APPENDIX 1 Floodplain Management Strategies & Guidelines

Transcription

1 APPENDIX 1 Floodplain Management Strategies & Guidelines A. Port Phillip Flood Management Plan (2012) B. Draft Flood Management Strategy Port Phillip and Westernport (2015) C. Revised Draft Victorian Floodplain Management Strategy (2015) D. Principles for Provision of Waterway and Drainage Services for Urban Growth (2007)

2

3 Flood Management Plan For City of Port Phillip and Melbourne Water March 2012

4

5 Table of contents Approval 1 1 Executive Summary 2 2 Background 4 3 Purpose 5 4 Objectives 6 5 Scope 7 6 The Municipalities Waterways and Drainage System The City of Port Phillip Waterways and Drainage Networks Flood History and Issues Flood Data, Information and Intelligence The Existing Knowledge Base 13 7 Flood Risk The Tolerability of Existing Flood Risk Existing Flood Risks within the Municipality Future Flood Risks Medium to Long-Term Pressures on the Drainage System 17 8 Flood Management and Mitigation Drainage Strategy Flood Modelling and Mapping completing the knowledge base Asset Management Planning Controls Capital Works Flood Emergency Response Planning Community Education and Awareness Flood Warning System Flood Proofing Drainage studies and guidelines 31 9 Roles and Responsibilities Improvement Plan Monitoring and Review How this document was developed Acknowledgements 51 ABBREVIATIONS & ACRONYMS 52 REFERENCES 53 APPENDIX A ROLES AND RESPONSIBILITIES 55 APPENDIX B - FLOOD RISK ASSESSMENT 58 APPENDIX C DATA, DRAINAGE SYSTEM UPGRADES & STUDIES 62 APPENDIX D FLOOD HOT SPOTS LIST AND MAP 73 Flood Management Plan for City of Port Phillip & Melbourne Water i

6 Approval This plan has been developed by the City of Port Phillip and Melbourne Water in consultation with the Victoria State Emergency Service. The plan will continually evolve as improved information becomes available to help manage flood risks across the Port Phillip municipality. As lead stakeholders for managing flood risks across the region, Melbourne Water and City of Port Phillip will endeavour to implement the recommendations made in this plan and also to review and update it as required on annual basis. Flood Management Plan for City of Port Phillip and Melbourne Water 1

7 1 Executive Summary The Flood Management Plan (FMP) has been developed in partnership between the City of Port Phillip and Melbourne Water as part of a joint focus on managing existing, residual and future flood risks within the City of Port Phillip. The genesis for that focus is provided in Melbourne Water s Port Phillip and Westernport Region Flood Management and Drainage Strategy (2007). Approximately 35% of the City of Port Phillip is three metres or less above sea level and the terrain is relatively flat. Flooding issues that have occurred within the City of Port Phillip include floods caused by high tides, floods due to pipe blockages and floods associated with intense rainfall events. The Flood Management Plan details the flood risks within the City of Port Phillip, particularly identifying any areas previously flood mapped, known hot spot or problem areas. Within its 20 km 2 municipality, Council has calculated that its flood zone affects 300 properties over an area of 38 Ha and the Special Building Overlay (SBO) impacts on 1,583 properties over 690 Ha. Additionally, modelling undertaken by Melbourne Water has identified approximately 9,052 properties within the City of Port Phillip that are affected by flooding from the catchment. Of these properties, 7,588 are considered to be at extreme risk; 636 are high risk; and 828 are medium risk. Areas and known hot spots of most concern within the municipality are the Elwood Canal (including Elster Creek extending to Koornang, Caulfield and Moorabbin) and Shakespeare Grove Main Drain. The Flood Management Plan details the potential impacts on flood risk from climate change within the City of Port Phillip. The predicted change in rainfall patterns within the Port Phillip and Westernport area is likely to lead to more frequent flash flooding and overland flow events associated with localised storm activity. At the same time, sea levels are expected to rise resulting in additional flooding pressures within the City of Port Phillip. Even a smaller sea level rise of 10 to 20 cm, which may occur over the medium term (i.e to 2045), is likely to impact on the drainage system within the City of Port Philip. The Flood Management Plan outlines roles and responsibilities and describes, at a high level, Council s and Melbourne Water s key flood management planning and management activities. There are a number of flood issues and knowledge gaps that have been identified in the Flood Management Plan that need to be addressed within the City of Port Phillip in order to effectively manage flood risks. These include a need for additional drainage asset information, flood modelling and mapping that does not take into account climate change impacts, need for more information to be made available to the community on flood risks and preparedness, need for major flood and emergency planning and flood management responses to climate change. An Improvement Plan has been developed which identifies the actions required to address the key issues and knowledge gaps identified in the Flood Management Plan. Actions include:

8 Development of a high level flood management framework or policy to communicate how the flood and climate change related Plans fit together Improvements to drainage asset management planning and information Ongoing communication networks to better share knowledge Investigate opportunities to mitigate extreme flood risks A more holistic approach to flood modelling and mapping Continue to understand climate change impacts on flood risk and effective drainage, with consideration of urban consolidation, sea level changes, tide levels, and potential changes to rainfall intensities Update and maintain planning scheme overlays to help prevent inappropriate development in flood prone areas Management of underground car parks Flood community education Flood emergency planning The Improvement Plan is detailed in Section 10 (page 35). The City of Port Phillip, Melbourne Water, VICSES and other flood management stakeholders have recognised the need for an integrated and sustainable approach where responsibility for activities is assigned on the capability of the agency to deliver. While key agencies can demonstrate the provision of specialised flood management skills in the planning for, response to and recovery from flooding there are opportunities to strengthen regional flood management arrangements through greater collaboration and more efficient use of resources. The Plan was developed by City of Port Phillip and Melbourne Water staff who worked in collaboration, with input from other agencies (particularly VICSES) through a series of interviews, file reviews, meetings, site visits and workshops, to gather the background information, identify flood risk management and mitigation activities, and arrangements, undertake a gap analysis and develop an improvement plan. This document was developed by the people listed in Section 12 (page 47), which includes workshop attendees and other contributors. The collaborative development of this Flood Management Plan and the Flood Response Plan for Port Phillip provides a basis for improved coordination and collaboration involving both technical and financial contribution in the future. Flood Management Plan for City of Port Phillip and Melbourne Water 3

9 2 Background This Flood Management Plan has been prepared in partnership between the City of Port Phillip and Melbourne Water as part of a joint focus on managing existing, residual and future flood risks within the City of Port Phillip. The genesis for that focus is provided in Melbourne Water s Port Phillip and Westernport Region Flood Management and Drainage Strategy (2007). The Port Phillip and Westernport Region Flood Management and Drainage Strategy (Melbourne Water, 2007), prepared by Melbourne Water in consultation with government departments, councils, emergency service organisations and other agencies, recognises that no single organisation and no single approach can deliver an effective response to flood management issues. A coordinated and collaborative approach by flood managers and communities is required. The five key objectives of the Strategy are: Objective 1: Completing the knowledge base (flood mapping and understanding social impacts) Objective 2: Potential long term future pressures on existing drainage systems (development in established areas and climate change) Objective 3: An agreed approach to managing existing regional flood problems (understanding intolerable flood risks) Objective 4: Enhanced community education, flood awareness and preparation Objective 5: Agreed responsibilities and improved collaboration between flood management agencies (integrated framework and flood management plans) One of the key outcomes from the strategy is the commitment from Melbourne Water to work with each Municipality within the region to produce a detailed local Flood Management Plan. This document represents the delivery on that commitment for the City of Port Phillip. 4 Flood Management Plan for City of Port Phillip and Melbourne Water

10 3 Purpose The Purpose of the Plan is to: Assist the City of Port Phillip and Melbourne Water to undertake their flood management responsibilities and ensure that suitable measures have been (or are being) implemented where possible to manage the existing and future risks associated with flooding. Ensure the objectives of the Port Phillip and Westernport Region Flood Management and Drainage Strategy can be effectively implemented in the City of Port Phillip in a coordinated and effective manner at a local level, within an integrated flood management framework. Assist the City of Port Phillip address their climate change concerns and commitments to future flood management and drainage effectiveness through linkage with the City of Port Phillip s Climate Adaptation Plan - Climate Adept City. Fostering preparedness for flood events and enhancing the ability to respond to floods in an informed and appropriate manner within the City of Port Phillip and its communities. While the Plan has due regard for current flood related legislation and supporting policies and strategies, it recognises that no single organisation and no single approach can deliver an effective response to flood management issues. It also recognises that it is not possible to make the City of Port Phillip completely free from flooding. A residual flood risk will remain that needs to be managed. Flood Management Plan for City of Port Phillip and Melbourne Water 5

11 4 Objectives The objectives in developing and maintaining this Flood Management Plan are to: Ensure that drainage and flood management matters within the Municipality are effectively managed and coordinated through flood management agency collaboration and partnership; Facilitate coordination and cooperation in the implementation of the five key objectives outlined by Melbourne Water (2007) with particular attention to existing flood risks; Promote improved collaboration between councils, Melbourne Water and SES Victoria; Understand flood risks and identify extreme/intolerable flood risks and hot spot areas; Identify gaps and improvement actions that are needed to address these risks and better prepare for and manage floods; Clarify the roles and responsibilities of stakeholders in addressing existing flood risks; and Continuously review drainage design and effectiveness needs with regard to future projected flooding impacts from a changing climate (including coastal inundation). 6 Flood Management Plan for City of Port Phillip and Melbourne Water

12 5 Scope While management of and preparedness for floods arising from waterways and drainage systems involves many different agencies, this plan is largely aimed at outlining the key activities, roles and responsibilities for Melbourne Water, the City of Port Phillip and the Victorian SES within a total system framework that recognises their joint responsibility for the management and ownership of the drainage system. Flood Management Plan for City of Port Phillip and Melbourne Water 7

13 6 The Municipalities Waterways and Drainage System 6.1 The City of Port Phillip The City of Port Phillip lies on the northern edge of Port Phillip Bay, to the south of the Melbourne central business district. It is approximately 20 km 2 in area with 11 km of foreshore and it has a population of 85,000. Approximately 35% of the Municipality is three metres or less above sea level and the terrain is relatively flat. The following figure shows the extents of the City of Port Phillip and the suburbs in the Municipality. The City of Port Phillip is bordered by the Cities of Glen Eira, Melbourne, Stonnington and Bayside. Figure City of Port Phillip Municipality The predominant land use is residential with a high proportion of flats and high rise accommodation. However, there are significant pockets of light and medium industry, notably in South Melbourne and Port Melbourne. The area has been extensively developed which reflects its location as an inner suburb of Melbourne. There are also areas of commercial offices, particularly along St Kilda Road and Queens Road. Albert Park Lake and the surrounding park land is also located in the municipality. 8 Flood Management Plan for City of Port Phillip and Melbourne Water

14 6.2 Waterways and Drainage Networks The City of Port Phillip drainage infrastructure was largely installed in the late 1800 s to the mid 1900 s, to standards and requirements applicable at the time. Since the installation of the drainage system the City of Port Phillip has seen intense development and in many situations the existing drainage does not cater for the requirements of today or meet today s design standards. The residential, industrial and commercial areas mainly consist of a piped drainage network (250 km) or concrete channel (2km) that conveys the stormwater to Port Phillip Bay or the Yarra River. The location and details of each drain and associated infrastructure are available on Geographic Information Systems (GIS) at the City of Port Phillip or at Melbourne Water. Melbourne Water is responsible for the installation and maintenance of drainage systems, including drain capacity and flood mitigation works, for catchments greater than 60ha 1. There are numerous pits and pipes along arterial roads and highways that are the responsibility of VicRoads. The Code of Practice for Operational Responsibility for Public Roads outlines how these drains are identified. On the next page is a map of the City of Port Phillip showing the main drains and the 100 year Average Recurrence Interval (ARI) (i.e. 1% Annual Exceedence Probability) flood extent for rivers and underground drains 2. The City of Port Phillip has surveyed and mapped all of its drains in three separate projects between 1998 and This survey information was input to Council s GIS system. These drainage maps contain some errors and omissions and ongoing work is required to improve their accuracy. 1 Melbourne Water is also responsible for managing Melbourne s waterways. 2 Map shows flood extent for Melbourne Water assets only. Flood extent does not reflect council owned drains or assets. Flood Management Plan for City of Port Phillip and Melbourne Water 9

15 Figure 6-2 Map of the City of Port Phillip showing the main drains and the 100 year ARI flood extent for rivers and underground drains 10 Flood Management Plan for City of Port Phillip and Melbourne Water

16 6.3 Flood History and Issues There have been three different types of flood issues that have occurred in the catchment that the City of Port Phillip and Melbourne Water have needed to manage: A. Flooding caused by high tides reducing the capacity of the stormwater drains to discharge runoff into Port Phillip Bay (for examples see Figure 6.3). B. Flooding due to pipe blockages from tree roots, sand, seaweed, tidal sand movement, debris on grates, runoff unable to get into pipes, broken pipes, etc (for examples see Figure 6.4). C. Flooding associated with intense rainfall events, which creates runoff greater than the capacity of the existing drain network (for examples see Figure 6.4). The frequency and consequences of these types of flooding has and will continue to vary. Typically the more severe flooding has occurred less often, but has had greater consequences, including causing flood damage and creating hazards. More frequent events have also caused damage and created hazards. However, more often more frequent events have resulted in nuisances such as water in streets. The recent flood history in the City of Port Phillip has been documented in two ways: 1. The City of Port Phillip maintains a customer service register which includes information reported to Council regarding drainage and flooding problems. The City of Port Phillip has produced maps showing the reported locations of drainage problems and flooding for the year s 2003 to 2010 inclusive (see Appendix D). 2. Council has a contractor that has maintained their drainage infrastructure since the year 2000 and responds to drainage issues and reported flooding with actions including traffic management and clearing of drain blockages, as well as regular maintenance. The locations where drainage / flooding problems are known to occur have been documented for this project as Flood Hot Spots. See Appendix D for a table and map of the flooding and drainage hotspots that have developed from opinions expressed at a workshop (Workshop #1, 17th May 2010) and a meeting held with the City of Port Phillip maintenance crew (4th June 2010). Flood Management Plan for City of Port Phillip and Melbourne Water 11

17 Marine Parade outfall submerged Barkly Meredith East Elwood Canal at Marine Parade Marine Parade (pit full) Elwood Canal at Marine Parade Elwood foreshore Figure 6.3 Flooding caused by high tides reducing the capacity of the stormwater drains to discharge runoff into Port Phillip Bay Main Drain Lynott Street east Wright Street north-side between Page & Richardson Streets Victoria Street on corner with Richardson Street Page Street at Kerferd Road north-west corner inlet McGregor Street between Canterbury & Richardson Streets Blessington Street Outfall B Figure 6.4 Flooding due to pipe blockages and flooding associated with intense rainfall events, which creates runoff greater than the capacity of the existing drain network 12 Flood Management Plan for City of Port Phillip and Melbourne Water

18 6.4 Flood Data, Information and Intelligence The Existing Knowledge Base Overview A summary of the flood related information for the City of Port Phillip catchment has been collated from studies/reports completed by the City of Port Phillip, Melbourne Water and DSE between 1998 and the present. The studies/reports detail hydraulic/hydrology modelling, monitoring data, records of floods, records of drainage/flood complaints, GIS information/plans, planning scheme overlays, council s MEMP (Municipal Emergency Management Plan), survey, cost estimates for implementing of recommendations, prioritised work programs and asset information. From this analysis a table has been developed detailing each report and its available information. The Flood Study Overview table (Appendix C) details the following information: The name of the study completed, the date it was completed and which company completed the works and initiated the works. The purpose and aim of the study. The methodology. The data collated and used. The main assumptions. The area covered. Outcomes and recommendations. A list of project deliverables. Maps available. Missing information. The City of Port Phillip has an extensive record of GIS information. A summary of this information is provided below. See Appendix C for a detailed list of the available data. Council drains and other drainage assets 100 year Average Recurrence Interval (ARI) flood extents for some Council drains. Municipal boundary. Suburbs/town names. Major and minor roads. Contours and digital terrain data Flood Management Plan for City of Port Phillip and Melbourne Water 13

19 Planning scheme maps Aerial photographs Property maps and details Melbourne Water also has a set of data for the City of Port Phillip area which includes: Catchment boundaries. 100 year Average Recurrence Interval (ARI) flood extents for Melbourne Water main drains and waterways Melbourne Water Main Drains and other main drain assets Contours and digital terrain data Waterways. The City of Port Phillip and Melbourne Water share this information with each other for the purposes of understanding drainage and flooding in the municipality and fulfilling their roles in managing drainage, waterways and flooding. Data and Knowledge Gaps There are aspects of the existing data/knowledge that is either not fully up to date, or where gaps in the data have been identified. These include: Asset Management: There is a need for improvement in the quality of information about drainage assets (particularly larger drains in the network (i.e. >600mm) to reflect what is on the ground and plan for asset renewal and form assessments of flood risks. There are some gaps in Council drainage asset information and Council is working on eliminating these gaps. Flood Modelling: Flood mapping was done ten years ago and does not include climate change scenarios. Flood mapping was undertaken using one dimensional hydraulic modelling techniques. Current two dimensional modelling techniques are expected to be better suited to representing flooding patterns in the City of Port Phillip (draft results are being developed for Melbourne Water for the Elwood Canal, Byron Street Main Drain and Shakespeare Grove Main Drain that use two dimensional flood modelling techniques). The Australian Rainfall and Runoff published in 1987 is currently under review, once completed the updated data will be used as required. 14 Flood Management Plan for City of Port Phillip and Melbourne Water

20 Climate change impacts on flood risk including sea level changes and potential changes to rainfall intensities have not been assessed (draft results are being developed for Melbourne Water for the Elwood Canal, Byron Street Main Drain and Shakespeare Grove Main Drain that include consideration of climate change effects). Historic mapping studies would not have considered a full range of ARI events or various tide levels nor urban consolidation. As a result analysis of depth and velocity is not currently possible for a range of ARI events. Planning: There is a need for future planning for flood damages prevention and response to climate change. There is a lack of clear direction within council on what is required in the design of underground car parks to protect them from floods. Community Education: There is a lack of information on flood risks and advice on how to prepare for and respond to floods. This may affect community awareness of the risk and preparedness for flooding. Emergency Planning: Lack of coordination and awareness of flood information will hinder flood mitigation and reduce efficiency of responses. These are described in the Improvement Plan (see Section 10), which describes known gaps and actions to address these gaps. Flood Management Plan for City of Port Phillip and Melbourne Water 15

21 7 Flood Risk 7.1 The Tolerability of Existing Flood Risk Melbourne Water uses a Flood Risk Assessment Framework (Melbourne Water, 2009) to identify and assess flood risks, based on a triple bottom line assessment, considering economic, social and safety factors. The Framework was developed in consultation with metropolitan councils and other stakeholders to provide a more transparent process to help people understand the decision making and flood mitigation prioritisation process. The Flood Risk Assessment Framework classifies flood risks, by catchment, as low, medium, high or extreme. Extreme flood risks are those considered to be intolerable. While flooding is a natural occurrence, in some cases the risks from flooding may be considered intolerable that is, so high that measures should be put in place to reduce the risks. For intolerable risk flooding a range of control measures will be considered with the aim of reducing the risk to a more tolerable level. Measures to be considered will include both engineering works and non-structural approaches. In most cases the risk will be reduced but not removed; a residual risk will remain. The City of Port Phillip has two catchments within its municipality that are identified as having extreme flood risk - Elwood Canal (including Elster Creek extending to Koornang, Caulfield and Moorabbin) and Shakespeare Grove Main Drain. Since catchments and Municipal boundaries do not necessarily coincide, it is possible that matters giving rise to or contributing to flood risk may be outside the Municipal boundary. Under such circumstances, Melbourne Water will ensure that the issue will be recognised and considered within the flood risk prioritisation; particularly in cases where the risk is assessed as being intolerable. 7.2 Existing Flood Risks within the Municipality Modelling undertaken by Melbourne Water to date has identified 9,052 properties within the City of Port Phillip that are affected by flooding from the catchment. Of these properties, 7,588 are considered to be at extreme risk; 636 are high risk; and 828 are medium risk. Within its 20 km 2 municipality, Council has calculated that its flood zone affects 300 properties over an area of 38 Ha and the SBO impacts on 1,583 properties over 690 Ha. The current list of Melbourne Water flood risks, by catchment, within the City of Port Phillip is provided at Appendix B. A map of the flood risk by catchment area, colour-coded by risk level is also shown in Appendix B. 16 Flood Management Plan for City of Port Phillip and Melbourne Water

22 The riverine and/or flash flood risk within the municipality has been assessed as High in the Port Phillip Municipal Emergency Management Plan (MEMP); based on the likely damage to property and environment, and number of people displaced. The MEMP may require review to update the risk assessment, and the identified treatment plans. The development of this Plan has involved identification of flood hot spots or a known flood problem area. A flood hot spot is an area of known flood problems, with a history of repeated flooding of a road crossing or property, often highlighted through anecdotal information or customer complaints. Identified flood hot spots for City of Port Phillip are identified in Appendix D. Typically the Flood Hot Spots relate to locations where flooding occurs on a frequent basis and tend to be localised flooding relating to blockages rather than riverine flash flooding. 7.3 Future Flood Risks Medium to Long-Term Pressures on the Drainage System This section considers the medium to long term pressures on the drainage system from urban development and climate change. Greenfields Development and Urban Expansion The City of Port Phillip is predominantly residential with a high proportion of flats and high rise accommodation. There are also significant pockets of light to medium industry. The area is already densely developed and has practically a zero rate of green fields development and urban expansion. Urban Consolidation and Infill Development Typically urban consolidation increases runoff and can either create drainage problems or exacerbate existing problems. The City of Port Phillip is already densely developed and existing sites have increased in height but not necessarily increased in ground cover. The height of the building adds no further impact to the existing drainage system as the impervious area stays approximately the same. It should be noted there is an increase in the number of under ground car parks in the area. If the underground car parks are constructed in areas with existing street flooding there is potential that overland flow will be directed into the underground car park and cause flooding if the construction does not account for the existing flood risk. This could exacerbate the flood damage and increase flood hazards. Melbourne Water has investigated redevelopment services schemes for Elwood Canal and Shakespeare Grove Catchments. These investigations recommended mitigation options that would be unfeasible or extremely difficult to implement and therefore these schemes have not been implemented by Melbourne Water. Consultation and ongoing discussion with the Flood Management Plan for City of Port Phillip and Melbourne Water 17

23 Council on flood awareness and preparedness, and having flood management plans were thought to be more appropriate and achievable. There are no specific drainage redevelopment schemes in the City of Port Phillip. Council s development engineer reviews specific project proposals and make decisions on drainage requirements on a project by project basis. The City of Port Phillip does have the C13 Port Melbourne development contribution scheme. However, it is not tied to any drainage projects. Climate Change Climate change has the potential to increase flood risk within the Port Phillip and Westernport region and hence the Port Phillip municipality. While the latest predictions are for a long-term reduction in catchment yield (i.e. a reduction in runoff volumes) it is likely that the intensity of extreme rainfall events will increase. The change in rainfall patterns is likely to lead more frequent flash flooding and overland flow events associated with localised storm activity. At the same time, sea levels are expected to rise resulting in additional flooding pressures within the City of Port Phillip. Even a smaller sea level rise, which may occur over the medium (i.e to 2045) term, is likely to impact on the drainage system within the City of Port Philip. For the City of Port Phillip, potential impacts of climate change have been detailed in the City of Port Phillip s Climate Adaptation Plan - Climate Adept City. A summary of the potential impacts to increase flooding are listed below: 1. Sea level rise, storm surge & storm tide Sea level rises are currently tracking at the upper end of all projections, with a rise of 10 to 20 cm by 2025, 40 to 55 cm by 2050 and 80 to 120 cm by However, there remains considerable uncertainty related to these projections. The observed projected rises in sea level for the City of Port Phillip are largely consistent with global projections. Middle Park, St Kilda and Elwood Beaches are particularly susceptible to potential loss. Higher water levels in Port Phillip Bay, result in reduced outlet capacity for the drainage system, increased siltation and sand build up in drains, infrastructure instability, reduced water quality and higher stormwater contamination, beach erosion and loss of beaches, loss of some coastal properties assets, impacts on the City of Port Phillip s coastal recreational spaces, trails and paths, higher maintenance costs, deposition of debris on beaches. 18 Flood Management Plan for City of Port Phillip and Melbourne Water

24 2. Intense Rainfall A changing climate will increase the magnitude (intensity and duration) of rainfall, wind, surge and storm events. The current estimates of potential changes in rainfall intensity due to climate change have large ranges. The City of Port Phillip is likely to experience a 1 in 5 year or 1 in 100 year storm event more regularly. For example, if rainfall intensity increases by 5% then a 100 year ARI storm under current climate would have an Average Recurrence Interval of 80 years in the future. However, if rainfall intensity were to increase by 20% under climate change then a 100 year ARI storm under current climate would have an Average Recurrence Interval of 30 years in the future. In terms of pipe capacity a drain that currently has its capacity exceeded on average once every 5 years would be exceeded on average every 4 years if rainfall intensity increased by 5% and on average once every 2.5 years if rainfall intensity increased by 20%. Strong winds often increase the magnitude of accompanying stormwater surges and intense rainfall. More intense rainfall events may result in more flooding, beach erosion or loss of beaches, more storm damage to buildings, roads, powerlines and recreational spaces, higher maintenance and insurance costs, more blackouts and lack of road access from extreme weather and reduce water quality in Port Phillip Bay and waterways. Climate risks for the City of Port Phillip were assessed by using the NATCLIM s assessment of local climate risks and impacts (Planning for Climate Change 2007 NATCLIM) as well as data from the CISRO and the Intergovernmental Panel on Climate Change to develop climate and greenhouse emissions scenarios (See Climate Change in the City of Port Phillip An Initial Perspective). The local assessment data was then updated to reflect the most recent climate assessments (Fourth IPCC Assessment Report 2007, Copenhagen Diagnosis 2009, CSIRO 2009). The update demonstrates higher climate risks than previously anticipated, with all risk tracking at the upper end or projections. Given the location and characteristics of the municipality and proximity to the coast, the expected impacts of climate change may be very significant in the City of Port Phillip. The most significant impact may well be increases in sea level rise. The Victorian Planning Provisions include a requirement to consider a potential sea level increase of 0.8 metres by the year A sea level increase of 0.8 metres would have a significant impact on flooding in the City of Port Phillip, because as suggested previously, even a smaller sea level rise of 10 to 20 cm that may occur in the medium term (i.e. 2025) is likely to impact on the drainage system. A map (Figure 7-1) has been produced of the City of Port Phillip showing 1.6 m and 2.4 m AHD contours that correspond to ground levels compared to water levels under current and future frequency of tidal inundation (please note that this map doesn t include any adaptation or flood defence actions, nor does it consider potential beach or coastal erosion). According to the National Coastal Vulnerability Study (February 2006), the City of Port Phillip has over 9,000 Flood Management Plan for City of Port Phillip and Melbourne Water 19

25 addresses within 3km of the coastline and below 4m in elevation, and it is these properties that will be most at risk from beach erosion and subsequent flooding. The table below indicates that should sea level rise of 0.8 metres occur, then the high tides we currently observe on average to be once every 100 years will occur approximately every 1 to 2 years. However, even a smaller change in sea level rise of 0.1 to 0.2 metres is likely to affect the capacity of drainage within the City of Port Phillip. The potential impacts associated with these higher water levels in Port Phillip Bay are described above. In addition, the future flooding risks include frequent inundation of some parts of the municipality that have high density and heritage value. Over time, this will substantially alter the fabric and characteristics of the current building stock. Progressively higher AHD levels and redrafted Flooding Overlay SBOs will also mean dramatic infrastructure upgrade challenges for the City of Port Phillip. Key tide levels include: Average Interval Recurrence Current estimated tide levels (Melbourne Water) Future estimated tide levels with 0.8 m sea level rise 1 year 0.7 m AHD 1.5 m AHD 10 year 1.1 m AHD 1.9 m AHD 100 year 1.6 m AHD 2.4 m AHD There are many challenges and uncertainties of additional pressures on drainage and flood management resulting from coastal inundation, especially as the data and design solutions are still being determined. Currently there remains a need to determine the extent of the inundation and to identify vulnerable areas along the coastline of the City of Port Phillip. In addition, flood modelling needs to be updated and drainage networks need to be analysed to determined reduced drainage capacity in the medium (i.e. 2025, 2045) and long term (i.e. 2070, 2100) with climate change. Future flood risks will increase due to the combined impacts of coastal inundation and intense rainfall. Over the coming years, continued modeling of climate change impacts on flooding from both waterways and coastal inundation will be needed to gain a more comprehensive picture of the total future flooding risks to the City of Port Phillip. In early 2007, the City of Port Philip published a report Climate Change in the City of Port Phillip An Initial Perspective. The report showed that the city faces significant climate change impacts in coming decades that will need to be managed. Since then the City of Port Phillip has develop a Climate Change Adaptation Plan, which outlines five key actions for council to begin to climate proof the city. One of the five actions relates directly to flood management. Six key sub actions related to flood management have been identified: 20 Flood Management Plan for City of Port Phillip and Melbourne Water

26 Complete updated flood modelling to determine new drainage design parameters. This includes obtaining data from neighbouring cities to understand this city s total drainage needs; Conduct drainage network analysis and map reduced capacity under medium term (2025, 2045) and long term climate risk projection (2070, 2100) to determine total drainage capacity required; Introduce and pilot innovative drainage design in priority areas, with capacity to monitor and evaluate performance during flooding events; Develop a Master Plan that ensures integration between drainage strategies and the following three areas coastal protection actions, water conservation and reuse actions in council s Water Sensitive City and Open Space Water Management Plans, and maintaining and building local roads; Increase the use of flood calming devices to reduce flood events water sensitive urban design applications, retention basis and systems; and Reduce pressures on the drainage network by introducing new development and building requirements to reduce/prevent future flooding in properties. Likely requirements include increasing absorbent surfaces, stormwater storage and treatment and water sensitive urban design applications. In addition, many of the other sub actions within the Climate Change Adaptation Plan are highly relevant to flood management, planning and response, particularly a number of actions that address coastal inundation flooding pressures. The Climate Change Adaptation Plan has been carefully considered in the development of the Improvement Plan (see Section 10). The City of Port Phillip along with nine other councils formed the Association of Bayside Municipalities (ABM) which represents the councils that have frontage to Port Phillip Bay and also represents a population of greater then one million. The ABM is committed to enhancing local government s effectiveness in the sustainable management of the Port Phillip Bay environment. One of the projects the ABM has recently been involved in is working with DSE to acquire a Digital Elevation Model (DEM) of Victoria s entire coast, which involved data collection of sea depths and land coordinate points. The DEM shows the lie of the land 10 metres above and 10m below sea level. The data for the DEM as gathered using LiDAR technology, which is an airborne laser system. Flood Management Plan for City of Port Phillip and Melbourne Water 21

27 Figure 7-1 Map of the City of Port Phillip showing predicted current and future frequency of flood levels to sea level rise 22 Flood Management Plan for City of Port Phillip and Melbourne Water

28 8 Flood Management and Mitigation This section captures what has been done within the Municipality to understand, identify and treat flood risks as well as what is planned to further improve the management of existing, future and residual flood risks. Flood control measures can be structural or non structural. 8.1 Drainage Strategy A number of drainage studies have been completed over the past 10 years as detailed in Section 6.5, although no specific drainage strategy for the entire municipality has been created. There are relevant reports that inform the way City of Port Philip manages its drainage including this plan, the 2009 Stormwater Action Plan, the Melbourne Water Flood Management Strategy and the Climate Adaptation Plan Climate Adept City and these have been considered in the development of the Improvement Plan (see Section 10). 8.2 Flood Modelling and Mapping completing the knowledge base Introduction Accurate survey and modelling of floodplains and overland flow paths is required to determine flood depths and delineate areas subject to inundation on floodplains and along overland flow paths. This information is aimed at improving community safety through informed planning (ensuring that new development is designed to take into account floodplain and overland flow paths and associated flow depths) and emergency response. The mapped information is therefore required not only by Melbourne Water as the floodplain management authority, but also by municipal planning departments, emergency response organisations, other infrastructure providers, land developers, prospective land purchasers and existing land owners and occupiers. The City of Port Phillip in conjunction with Melbourne Water is initiating a flood mapping project aimed at mapping the overland flow paths for nominated storm intervals for all main drain catchments within the Municipality. Some pilot studies are underway using two dimensional flood modelling and considering climate change impacts on flood models. This is a critical first stage in achieving a safer community. The City of Port Phillip, in conjunction with other regional stakeholders and Melbourne Water, plans to initiate further coastal inundation modelling and mapping to determine risks to the City of Port Phillip associated with inundation from Port Phillip Bay as well as from stormwater. Catchment and coastal inundation data under various climate change scenarios will be brought together to understand total future flooding risks and drainage Flood Management Plan for City of Port Phillip and Melbourne Water 23

29 needs for the municipality. The flood information developed by the project will be used to give flood advice on properties affected by overland flow and / or flood inundation along Melbourne Water and City of Port Phillip drains, and to enable Melbourne Water and the City of Port Phillip to set capital works programs by identifying relative flood risks. The information will also be used to assist in determining land development requirements. In addition, the 100 year ARI flood extents determined through the project will be incorporated as a Special Building Overlay, Land Subject to Inundation Overlay, Floodway Overlay or Urban Floodway Zone as appropriate, in the Port Phillip Planning Scheme under the Victorian Planning Provisions. Mapping Program In the late 1990 s and early 2000, flood mapping studies were undertaken in the City of Port Phillip catchment area as detailed in Section 6.5 (refer to Appendix B for detail on each study). The studies produced scaled plans showing the extent of flood inundation for a 100 year ARI flood event, the flood mapping was primarily based on hydrologic modelling (RORB) and one dimensional hydraulic modelling only. To date, flood mapping for various tide levels, that includes a full range of ARI events and that includes ranges of depths and velocities to represent varying hazards across the flood prone areas has not been done. Also climate change impacts on flood risk including sea level changes and potential changes to rainfall intensities have not been assessed. Melbourne Water is undertaking flood mapping in for the Elwood Canal, Byron Street Main Drain and Shakespeare Grove Main Drain that use two dimensional flood modelling techniques. The mapping currently being done includes the consideration of climate change effects. The City of Port Phillip has engaged URS to carry out mapping for a range of ARI s for 5 year, 20 year, 50 year, 100 year and PMF. Council is also proposing to initiate coastal hazards vulnerability assessment (CHVA) with other stakeholders including Melbourne Water in order to determine impacts from coastal inundation. 8.3 Asset Management It is important that the existing drainage infrastructure within the City of Port Phillip operates as intended. This is especially important in the City of Port Phillip due to the density of development, flat terrain, drains located below sea level, risks of sand blockage for beach outlets and the age of the drainage infrastructure. Drainage and flood mitigation assets are maintained to a fit for purpose state to ensure they work as designed during a flood. All Melbourne Water drainage assets and waterways have an ongoing inspection and maintenance program. 24 Flood Management Plan for City of Port Phillip and Melbourne Water

30 Melbourne Water has significant drainage assets that require maintenance and renewal. Melbourne Water drainage assets are managed in accordance with the Asset Management Guidelines and Strategic Asset Management Plans, e.g. with the level of service of no failure/collapse of significant drain. Melbourne Water main drain conditions are assessed and reported annually in the State of the Assets Report. In the last few years Melbourne Water has undertaken work on the Shakespeare Main Drain outlet to reduce the risk of sand blockage and drainage and other problems. Work has also been completed on the Cowderoy Street Main Drain to assess corrosion and to undertake structural repairs. Melbourne Water waterways have ongoing programs to remove flow restrictions such as dumped rubbish, shopping trolleys and willow trees. The City of Port Phillip has an active road and pit cleaning service, but pipes are only cleaned on a reactive basis. Leaf blockage is a major problem in the municipality and it is thought that blockages and maintenance issues are the main reason for flooding rather than the actual level of service of the assets. There are continual silt and litter blockages, along with illegal connections. Given the relatively low lying and flat nature of much of the city the normal flows in the drains are often not sufficient to flush silt, leaves and litter out of the drainage pipe system. The City of Port Phillip has put in considerable effort into maintaining the performance of its drainage infrastructure over the last ten years or so, including: Reviewing the capacity of all of their drains in 1998 to 2000 and then upgrading high priority drains to provide a 5 year ARI level of service in the drain capacity Contracting the drain maintenance and repairs since the year 2000 with defined tasks and performance for regular inspection and clearing of drains. The current Council spending on these activities is approximately $440k drainage maintenance and $600k renewal It is expected that this expenditure will need to grow in the future to include more asset renewal as well as more maintenance and other operating expenses. Council has identified a need for further investment in asset management to improve its response to flooding issues within the municipality and has been responded to within the Improvement Plan (see Section 10). This includes additional and new costs for developing new drainage design solutions and gaining a drainage network that is deemed to capably provide effective drainage for future flooding risks from a changing climate. 8.4 Planning Controls Melbourne Water Melbourne Water is the Regional Floodplain and Drainage Authority for the Port Phillip and Westernport region. Thus all applications for subdivision and developments on flood prone land are referred by Council to Melbourne Water, Flood Management Plan for City of Port Phillip and Melbourne Water 25

31 as the authority responsible for the administration of the Planning Scheme, under Section 55 of the Planning and Environment Act, This includes consideration of flooding and projected rises in mean sea levels. However, this does not extend to factors contributing to coastal physical vulnerability such as storm surge and erosion. Melbourne Water has developed interim guidelines to assist in assessing development proposals affected by tidal inundation and flooding associated with sea level rise (Melbourne Water 2010). New flood levels for areas affected by predicted sea level rise to be applied for planning purposes are an increase on existing year flood levels of 200mm by 2040 and 800mm by These new flood levels should be used in accordance with the principles and core requirements contained in Melbourne Water s Guidelines for Development in Flood-Prone Areas. The Melbourne Water Guidelines link directly with the Department of Sustainability and Environment Draft Guidelines that direct/assist authorities assessing development in coastal flood risk areas such as within the City of Port Phillip (DSE 2010). Council The City of Port Phillip Planning Scheme contains a Special Building Overlay (SBO) which applies to land liable to overland flows from urban piped drainage systems (see Figure 8.1). Figure 8.1 also shows the 100 ARI flood extent. The 100 year ARI flood extents determined through the flood mapping project initiated by the City of Port Phillip in conjunction with Melbourne Water (see Section 8.2) will be incorporated as additional Special Building Overlays, Land Subject to Inundation Overlays, Floodway Overlays or Urban Floodway Zones as appropriate, in the Port Phillip Planning Schemes under the Victorian Planning Provisions. In addition, Council intends to update their Special Building Overlay controls in response to climate change and informed by flood/inundation mapping that will incorporate climate change scenarios (see Improvement Plan Section 10). In addition, to the update of the Special Building Overlay, there is the possibility that new flood information may also be incorporated into the development of a new climate change overlay. New formal arrangements and interagency coordination would be required to develop and support the development of a new overlay such as this. The State Government will be responsible for appropriate planning controls on climate change affected areas which will provide direction to Melbourne Water and the City of Port Phillip. The City of Port Phillip has no specific drainage redevelopment schemes in place at this time. They have the C13 Port Melbourne development contribution scheme but it is not tied to drainage projects. The development engineer considers specific projects if referred to him and makes decisions on drainage requirements as needed. 26 Flood Management Plan for City of Port Phillip and Melbourne Water

32 Figure 8.1: City of Port Phillip SBO and 100 ARI Flood Extent Flood Management Plan for City of Port Phillip and Melbourne Water 27

33 8.5 Capital Works Drainage Improvement Capital Works Programs Both Council and Melbourne Water have capital works programs for drainage works in the City of Port Phillip. City of Port Phillip Council have a $600,000 budget for renewal and enhancement of the Council drainage network that has been predominantly spent on renewals and replacement of minor drains in critical areas aiming at a 1 in 5 year stormwater capacity. Council s Water Plan and its implementation plans identify key actions to address local stormwater pressures on council drainage including delivering stormwater harvesting in open space areas within the City of Port Phillip. Council intend to develop a capital program to deliver stormwater harvesting projects in 2010/11 and beyond. Additionally, Council s Open Space Water Management Plan identifies the use of alternative water sources (such as stormwater harvesting) and such measures could help to address council s need for drainage improvement. Future capital works planning requires a body of work based on up to date information, climate change and the capabilities of the system (particularly in the area of flood modelling and mapping) to give better direction. Melbourne Water Melbourne Water has a 5 year Water Plan that documents their proposed capital works program. Melbourne Water puts projects into the Water Plan (and onto annual Capital Works programs) based on a number of criteria, including: Works to reduce flood risk Works to renew assets Works to improve stormwater quality, etc. Actions from this Flood Management Plan and from subsequent flood modelling and drainage analyses are expected to find the need to increase capital expenditure on drainage works in the City of Port Phillip. Planning horizons may need to be increased to look forward to at least understand the potential budget requirements for works to enable the drainage works in the City of Port Phillip to cope with the need for renewal, for works to mitigate existing flooding risks and also for works to mitigate future flooding risks due to climate change. In particular a capital works plan is expected to need to be developed to cope with predicted sea level rise in coming decades. 28 Flood Management Plan for City of Port Phillip and Melbourne Water

34 8.6 Flood Emergency Response Planning Planning is crucial to ensuring an effective proactive emergency response to flooding when it occurs. Planning must be conducted within the legislated framework as well as having a process that is established and well understood by all stakeholders. Further, planning must be based on a sound understanding of flood risk. In addition, communication and consultation are essential in achieving ownership of flood emergency plans by all stakeholders, especially the community. Ownership of flood emergency plans ensures that stakeholders are more likely to respond to floods in accordance with strategies and arrangements detailed in the plan. Municipal Emergency Management Plan (MEMP) and Flood Emergency Plan Flood response and recovery arrangements are detailed in the Municipal Emergency Management Plan (MEMP) and its sub plan, Flood Emergency Plan. VICSES has implemented a Regional Flood Response Plan which, together with the State Flood Response Plan, will facilitate a consistent and coordinated approach to flood response within the City of Port Phillip in the lead up to, during and after a flood event. In developing this Flood Management Plan, a range of information relating to flooding from waterways and overland flows within the Municipality has been collated. The intelligence in this information can be used as a basis for the further development of a Flood Emergency Plan with VICSES. The Flood Emergency Plan is consistent with the VICSES regional plan and is maintained by and available from the Municipal Emergency Response Officer (MERO). All information and intelligence developed and collated as part of this Flood Management Plan and as a result of the studies and work that flow from its implementation should, as a matter of course, be made available for consideration and incorporation into the Flood Emergency Plan. Similarly, during and immediately after a flood it is important that key aspects of the event are recorded so that the Flood Emergency Plan and its associated actions can be improved and future flood damage better contained. Arrangements for data collection and collation are detailed in the Flood Emergency Plan. 8.7 Community Education and Awareness The City of Port Phillip, Melbourne Water and VICSES are working together to create flood awareness within the Port Phillip community. VICSES are working in conjunction with the City of Port Phillip to engage with the community to increase awareness of flood safety through the implementation of short and long term education programs including StormSafe and FloodSafe. Flood Management Plan for City of Port Phillip and Melbourne Water 29

35 This includes working to ensure that community members: Are aware of the flood threat in their area and the level at which their property might be inundated; Understand that works within an overland flow path or on a floodplain will have some impact on flood behaviours and the need to ensure that such works do not create additional flood problems elsewhere; Have access to material about how to protect themselves and their property against flood (e.g. personal flood planning); Know the location of or how to find out the location of evacuation centres; Are aware of the importance of advising Police when they make their own decisions to evacuate; and Are aware of the general contents of the MEMP Flood Emergency Plan. Council also recognises the need to work to ensure that residents, business owners / operators and visitors are aware of the flood risk and of appropriate flood response actions. The City of Port Phillip has initiated the following actions through its Climate Adaptation Plan Climate Adept City: The development of a Local Community Action Plan, with the objective of working with local communities to develop a locally relevant, communitybased climate resilience action plan, which will include flood management elements; and The development of strategies for increasing community awareness and action during emergency events such as flooding. The incorporation of flooding zones and overlays into the planning scheme raises community awareness of flooding issues. The notification of the amendment, along with the inclusion of flood maps as overlay controls makes flooding information readily accessible to the community and ensures that site constraints and likely development requirements are flagged to developers and property owners. Planning information, including flooding overlays is disclosed to prospective purchasers through planning certificates issued under Section 199 of the Planning and Environment Act, 1987 and included as a compulsory part of the vendor s statement issued under Section 32 of the Sale of Land Act, Flood Warning System Melbourne Water has a 24 hour alarm based flood warning system whereby waterway levels and rainfall are evaluated against trigger levels and communicated to Bureau of Meteorology when exceeded. BOM will subsequently issue a flood warning to the community and key agencies (such as VICSES). There are nine waterways in the Port Phillip and Westernport region that Melbourne Water provides warnings for. Due to the time required (approximately six hours) flood warning systems on waterways are not of benefit in the City of Port Phillip as flash flooding from the drainage system in 30 Flood Management Plan for City of Port Phillip and Melbourne Water

36 the main source of flooding. However, the height of the Yarra River does impact flooding in the municipality. VICSES has Standard Operating Procedures (SOP) for flood operations, such as SOP 009 Notification Process for Flood Warnings, where in response to the information provided by the BOM; information is passed to relevant agencies on the basis of a Flood Watch or Flood warning. The SOP lays out the communication and notification responsibilities. 8.9 Flood Proofing The Climate Adaptation Plan - Climate Adept City proposes to develop guidelines and local requirements to encourage and accelerate the development of climate proof buildings including flood resistant buildings. This will target demonstration projects and the development of design specifications for trialling in areas deemed as a priority Drainage studies and guidelines Melbourne Water and City of Port Phillip have undertaken drainage studies and developed guidelines to address flooding. Guidelines for Development in Flood prone Areas Melbourne Water has developed guidelines to assist property owners, developers, designers and builders to understand the broad principles and specific requirements that apply to property development in flood-prone areas within the Melbourne metropolitan area. The guidelines address requirements in both floodplain and overland flow path areas and supplement the Land Development Manual (Melbourne Water, 2009c). Water Sensitive Urban Design Guidelines Melbourne Water and City of Port Phillip (in conjunction with other Councils) have prepared Water Sensitive Urban Design (WSUD) Guidelines that set out Council s expectations for WSUD projects within the municipality, to inform developers and consultants. The document provides information on the approvals process, design considerations, suitability of WSUD types in different conditions and considerations for construction, protection, maintenance and handover of WSUD assets (Melbourne Water et al, 2009). Drainage Studies Relevant drainage and flood related studies are detailed in Appendix C. Flood Management Plan for City of Port Phillip and Melbourne Water 31

37 9 Roles and Responsibilities Agreed Responsibilities Flood management in the context of waterways and drainage systems is complex and includes elements of prevention, preparedness, response and recovery. The tools used to reduce exiting and future flood risk and manage residual flood risk comprise a variety of structural and non-structural measures: engineering works to improve flood protection 3, land use and other planning controls, flood warning systems, programs of education, response and recovery, etc. No single agency or stakeholder is able to deliver on all these measures. Collaboration between agencies is essential for the development of coordinated and integrated flood management programs and activities. A clear understanding and common agreement on respective roles and responsibilities is essential to effective collaboration, particularly between Melbourne Water, City of Port Phillip and VICSES. Table 9-1 provides the weight of Melbourne Water s, City of Port Phillip s and SES Victoria s flood management roles in relation to prevention, response or recovery, which is represented by the number of ticks. Table 9-1: Weight of Flood Management Roles Organisation Prevention Response Recovery Melbourne Water City of Port Phillip Victoria State Emergency Service A summary of key stakeholder roles and responsibilities is provided in Appendix A. Of the organisations noted in the table presented in Appendix A it is Melbourne Water and the City of Port Phillip that have major roles in flood management within the City of Port Phillip. In addition, the Victoria State Emergency Service has an important role in supporting emergency planning, response and recovery. Additionally, the Bureau of Meteorology also has a role related to flood forecast and warning as well as longer term climate predictions and analysis and water information. Other Australian Government organisations noted have a funding/financial assistance role. Organisations noted within the State of Victoria are more broadly related to emergency planning, response, recovery or funding 3 It is not practical or feasible to build infrastructure capable of alleviating all flooding. 32 Flood Management Plan for City of Port Phillip and Melbourne Water

38 role apart from the Environment Protection Authority, which assess the environmental impact of floods. Under the Water Act 1989 Melbourne Water is the designated care taker of rivers and creeks and the drainage and floodplain management authority for the Port Phillip and Westernport region. In this role, Melbourne Water is responsible for providing a safe level of flood protection for the community (refer to Appendix A for further details). Melbourne Water is required to meet the Statement of Obligations issued by the Minister for Water under the Water Industry Act These obligations include the requirement to provide a safe and effective system for dealing with storm run-off, a reduced risk of flooding in priority areas and the prevention of inappropriate development in flood-prone areas (Melbourne Water 2008). Local government is primarily responsible for the planning and provision of services and facilities for the local community, and for providing and maintaining community infrastructure. Unlike Melbourne Water, the City of Port Phillip does not have any statutory responsibility for floodplain management. However, the City of Port Phillip has a significant role in managing the stormwater drainage system through its role as a planning authority and emergency management agency. Under the Local Government Act 1989, public drains are vested in Council S198 and a function of Council is to provide and maintain community infrastructure S3D the City of Port Phillip is required to ensure that resources are used efficiently and effectively and services are provided in accordance with Best Value Principles to best meet the needs of the local community. The City of Port Phillip is also responsible for providing and maintaining community infrastructure (Victorian Parliament 1989). Under the Emergency Management Act 1986, the City of Port Phillip must prepare a municipal emergency management plan and appoint a Municipal Emergency Resource Officer. Responsibility for the immediate response to a flooding emergency rests with the Victorian State Emergency Service, but the City of Port Phillip coordinates recovery activities such as the clean-up of debris. When a more widespread municipal emergency is declared, the City of Port Phillip s Municipal Emergency Resource Officer coordinates the immediate response. In addition to the relevant key legislation that relates to flood management in the City of Port Phillip, there is a memorandum or understanding that was developed in 1927 between the Board of the (then) predecessor of Melbourne Water and Local Councils. Under this agreement, which is still recognised, responsibility/jurisdiction for drainage management is jointly shared and is determined by the area of the catchment, namely: for areas up to 60 hectares, responsibility rests with the relevant local council; and for areas over 60 hectares, responsibility rests with Melbourne Water. Flood Management Plan for City of Port Phillip and Melbourne Water 33

39 In the context of the Port Phillip and Westernport Region Flood Management and Drainage Strategy and this Flood Management Plan, the above leads to the following expectations: That Melbourne Water will: Provide Councils with technical and financial assistance in the preparation and maintenance of a Flood Management Plan (this document) that identifies existing flood risks, identifies intolerable risks including from climate change impacts and prioritises works and activities aimed at reducing that risk and improving regional flood management; Assist in the funding and management of prioritised works and activities identified in the Flood Management Plan and in their implementation (as required) at regional level; Provide financial and technical support to Councils and VICSES in order to enhanced community flood education, awareness and preparedness across the region; Continue to support Councils in land use management and other activities aimed at reducing existing and future flood risk and damages; and Provide Council with the results of studies and analyses as well as data gathered during and after flood events for inclusion in the MEMP Flood Emergency Plan. That Council will: Work with Melbourne Water to prepare and maintain a Flood Management Plan (this document) that identifies existing flood risks, identifies intolerable risks including from future climate change impacts and prioritises works and activities aimed at reducing that risk and improving regional flood management; Assist in facilitating the delivery of prioritised works and activities identified in the Flood Management Plan and in their implementation (as required) within the Municipality with due regard for inter-municipality issues; Incorporate flood mapping outputs into the Planning Scheme as appropriate zones and overlays and ensure that the flood provisions are sufficient and consistent with assessed risk and the aim of reducing existing and future flood risk and damages; Support VICSES in the delivery of programs aimed at enhancing community flood education, awareness and preparedness across the Municipality; and Maintain the Flood Response Plan (MEMP Flood Response Plan) as a joint owned plan with VICSES, through routine review and incorporation of intelligence extracted from flood related studies and analyses and knowledge gained through operational flood experience. 34 Flood Management Plan for City of Port Phillip and Melbourne Water

40 Improved Collaboration The City of Port Phillip, Melbourne Water, VICSES and other flood management stakeholders have recognised the need for an integrated and sustainable approach where responsibility for activities is assigned on the capability of the agency to deliver. While key agencies can demonstrate the provision of specialised flood management skills in the planning for, response to and recovery from flooding there are opportunities to strengthen regional flood management arrangements through greater collaboration and more efficient use of resources. The collaborative development of this Flood Management Plan and the Flood Response Plan for Port Phillip provides a basis for improved coordination and collaboration involving both technical and financial contributions. 10 Improvement Plan This Part of the Port Phillip Flood Management Plan lists those activities planned by City of Port Phillip in conjunction with Melbourne Water in order to reduce the risk of flooding and the associated level of intolerability. It reflects an understanding of the flood risks and proposes a program for mitigating those risks within Port Phillip that are assessed as being intolerable in the context of current standards, anticipated future climate change impacts and community expectations with appropriate regard for regional issues and priorities. The actions below outline the agreed approach to managing existing and future regional flood problems within Port Phillip. They were identified through a gap analysis performed on flood mitigation and management measures to identify gaps or areas requiring improvement. In the table, the lead agency responsible for the action is shown in bold. Where the action has a cost impact, this has been flagged in the table. Detailed costing analysis will need to be done for some of these. Flood Management Plan for City of Port Phillip and Melbourne Water 35

41 Action Plan Linkage to Flood Action Number Issue/Gap Location Priority (L, M, H) Cost impact? Timing Responsibility (lead in bold) Action Existing flood Management and Drainage Strategy (MelbWater, 2007) risk Future flood risk Knowledge Education, base awareness and Responsibilities and 1. Policy and Framework 1 There is a need for an High Dec CoPP Develop a high level flood management overarching framework or 2011 framework or policy to provide overview policy to communicate how the flood and climate change related Plans fit together 2. Asset Management 2.1 Survey of drainage assets and update GIS 2 The current Drainage Asset June CoPP Further develop the Drainage Asset Management Plan doesn t 2012 Management Plan to identify any gaps in identify gaps and assets or planning information improvements 3 There is a need to improve the CoPP Medium Yes a. June CoPP a. Develop a program for asset condition Y Y quality and extent of focus 2012 inspections. Determine indicative costing information about drainage Hot and make a budget bid. assets (particularly for council Spots b. June b. Implement an ongoing CCTV pipe drains >600mm). This will 2013 survey program to progressively improve 36 Flood Management Plan for City of Port Phillip and Melbourne Water

42 Linkage to Flood Action Number Issue/Gap Location Priority (L, M, H) Cost impact? Timing Responsibility (lead in bold) Action Existing flood Management and Drainage Strategy (MelbWater, 2007) risk Future flood risk Knowledge Education, base awareness and Responsibilities and assist in the development of asset data and condition information. asset renewal programs and in c. June c. Update GIS information. Records to assessing flood risks include location of pits/pipe inverts and diameters, drains, condition and age of There are gaps and system. Give Priority to the 36 identified connectivity issues in council s hot Spots. GIS drainage data due to d. June d. Update GIS information to include previous data collection 2013 flood scenarios maps (methodology and methodology that need modelling) for both coastal and resolution. catchment inundation. e. June e. Use Council s GIS system or a product 2013 such as waterride to store modelling results. 4 As above June 2012 MW Note: This action relates to Survey (CCTV) and Survey of Council Drainage System action within Council s Stormwater Action Plan. Review and provide GIS data to CoPP on hotspots associated with MW assets Flood Management Plan for City of Port Phillip and Melbourne Water 37

43 Linkage to Flood Action Number Issue/Gap Location Priority (L, M, H) Cost impact? Timing Responsibility (lead in bold) Action Existing flood Management and Drainage Strategy (MelbWater, 2007) risk Future flood risk Knowledge Education, base awareness and Responsibilities and 2.2 Development and implementation of maintenance program and ongoing update of GIS 5 There is a need for more allocation of funds to support the proactive and timely response to flooding issues associated with the maintenance of drainage assets to maximise capacity. It is currently predominately a reactive response. There is an ongoing need to obtain information about drainage assets (particularly drains >600mm) to reflect what is on the ground and plan for asset renewal and form assessments of flood risks. CoPP focus Hot Spots High a. June 2012 b. June 2012 c d. June 2013 CoPP MW a. Develop a maintenance program that includes proactive maintenance (cleaning) of pipes and drains and the ongoing inspections (CCTV) of drainage assets to determine their condition and serviceability. b. Give priority to 36 identified hot spots locations and areas with a potential for flood damage. c. Update GIS information with asset related data captured during maintenance work. d. Implement a risk based maintenance program. Note: This action relates to the Risk Based Maintenance Program action within Council s Stormwater Action Plan. Y Y Y 38 Flood Management Plan for City of Port Phillip and Melbourne Water

44 Linkage to Flood Action Number Issue/Gap Location Priority (L, M, H) Cost impact? Timing Responsibility (lead in bold) Action Existing flood Management and Drainage Strategy (MelbWater, 2007) risk Future flood risk Knowledge Education, base awareness and Responsibilities and 2.3 Knowledge sharing 6 Knowledge sharing is lacking CoPP High Initiate MW a. Identify contacts and roles and form a Y Y Y Y within council and between by June CoPP drainage group. key organisations in relation to 2012 VicRoa b. Meet annually to discuss priority drainage asset management. Ongoing ds drainage, flooding issues and flooding risks to infrastructure. c. This group to provide key input to the development of the CoPP Drainage Asset Management Plan. Note: This action relates to the Drainage Asset Management Plan and the Climate Adaptation Plan 2.4 Capital Works 7 There is no forward capital CoPP Medium a. Apr MW a. Verify flood risk ratings in Melbourne Y Y Y works program to address key focus 2012 CoPP Water s Flood Risk Matrix & identify hot spots and flood risk areas. Hot VicRoa extreme risk (sub)catchments. Spots b. June ds b. Investigate opportunities to mitigate 2013 extreme flood risks. c. c. Review hot spot areas and consider for Flood Management Plan for City of Port Phillip and Melbourne Water 39

45 Linkage to Flood Action Number Issue/Gap Location Priority (L, M, H) Cost impact? Timing Responsibility (lead in bold) Action Existing flood Management and Drainage Strategy (MelbWater, 2007) risk Future flood risk Knowledge Education, base awareness and Responsibilities and ongoing capital works based on priority risk rating. 8 There may be a need for CoPP Medium June CoPP a. Utilise Melbourne Water s Flood Risk Y Y Y specific capital works to focus 2013 MW Matrix, hot spots information, outcomes address some key hot Hot ongoing VicRoa of flood modelling and flood damages spots/flood risk areas Spots ds assessment (if undertaken) b. Investigate opportunities to address risks and develop a forward capital works program for drainage upgrades based on priority and risk. Note: This action relates to the Capital Works Identification action within Council s Stormwater Action Plan. 3. Flood Modelling and Mapping 3.1 Modelling approach 9 Lack of common and holistic CoPP Medium Initiate MW a. Ensure all inundation modelling Y Y Y approach to flood modelling. by Dec CoPP integrates both catchment and coastal 2011 inundation, and is periodically updated to Ongoing include the latest climate science on rainfall and sea level rise. 40 Flood Management Plan for City of Port Phillip and Melbourne Water

46 Linkage to Flood Action Number Issue/Gap Location Priority (L, M, H) Cost impact? Timing Responsibility (lead in bold) Action Existing flood Management and Drainage Strategy (MelbWater, 2007) risk Future flood risk Knowledge Education, base awareness and Responsibilities and b. Discuss and agree on priorities and approach to enable consistency across the region with all municipalities. c. Discuss and support each other with flood modelling and mapping project. d. Provide technical advice and ongoing coordination. Note: This action relates to the CoPP Flood Management framework and the Climate Adaptation Plan. 3.2 Completing the knowledge base 10 Climate change impacts on CoPP Medium a. June MW a. Continue to understand climate change Y Y Y Y flood risk including taking into and MW 2012 CoPP impacts on flood risk and effective account current and future drains b. g. drainage, as required by the CoPP climate change scenarios. Ongoing Climate Adaptation Plan. Urban consolidation, sea level b. Complete Elwood Canal, Byron Street changes, tide levels, and Main Drain and Shakespeare Grove Main potential changes to rainfall Drain flood mapping (that include intensities need to be consideration of climate change effects) Flood Management Plan for City of Port Phillip and Melbourne Water 41

47 Linkage to Flood Action Number Issue/Gap Location Priority (L, M, H) Cost impact? Timing Responsibility (lead in bold) Action Existing flood Management and Drainage Strategy (MelbWater, 2007) risk Future flood risk Knowledge Education, base awareness and Responsibilities and considered in any modelling. c. Undertake floor level surveys of buildings within the modelled flood prone areas and determine flood damages for each building based on depth and frequency of below or above floor flooding. d. Melbourne Water to liaise with CoPP regarding any changes/modelling updates and any other modelling requirements. e. Ensure mapping considers the latest science and suitable range of ARI events and modelling techniques. f. Model and map all flooding pressures (riverine/overland/sea level rise/storm inundation/tidal inundation, urban consolidation) together. g. Review/update Melbourne Water Flood Risk Matrix. 42 Flood Management Plan for City of Port Phillip and Melbourne Water

48 Linkage to Flood Action Number Issue/Gap Location Priority (L, M, H) Cost impact? Timing Responsibility (lead in bold) Action Existing flood Management and Drainage Strategy (MelbWater, 2007) risk Future flood risk Knowledge Education, base awareness and Responsibilities and Note: This action relates to the Hydraulic Modelling (existing conditions), Hydraulic Modelling (with climate change) actions within Council s Stormwater Action Plan and the Climate Adaptation Plan. 11 CoPP Medium Ongoing CoPP a. CoPP to engage with MW and seek Y Y Y Y CoPP MW guidance and advice (i.e. likely budgetary drains requirements, approach) for the completion of flood modelling of Council drains across City of Port Philip. b. City of Port Phillip to complete flood modelling for Council drains across City of Port Phillip (that includes consideration of climate change effects). Note: This action relates to the Hydraulic Modelling (existing conditions), Hydraulic Modelling (with climate change) and Database of Modelling Results actions Flood Management Plan for City of Port Phillip and Melbourne Water 43

49 Linkage to Flood Action Number Issue/Gap Location Priority (L, M, H) Cost impact? Timing Responsibility (lead in bold) Action Existing flood Management and Drainage Strategy (MelbWater, 2007) risk Future flood risk Knowledge Education, base awareness and Responsibilities and within Council s Stormwater Action Plan. 4 Major Flooding and Planning 4.1 Future flood damages prevention and response 12 Planning schemes need to be Dec MW Melbourne Water and CoPP to update MW kept up to date as modelling 2012 CoPP flood overlays (SBOs) in the Port Phillip and mapping is completed to Planning Scheme after the flood help prevent inappropriate modelling has been completed for Elwood development in flood prone Canal, Shakespeare Grove and Byron areas Street Main Drain, including public exhibition which will raise awareness. 13 There is a need for future CoPP Medium June CoPP a. Update CoPP flood overlays (SBOs) Y Y Y Y Y flood damages prevention and 2012 MW after the flood modelling has been response to climate change. Ongoing DPCD completed and raise awareness. b. Identify controls and manage risks in accordance with the Climate Adaptation Plan considerations once modelling is completed. c. Develop long term plan to decide on 44 Flood Management Plan for City of Port Phillip and Melbourne Water

50 Linkage to Flood Action Number Issue/Gap Location Priority (L, M, H) Cost impact? Timing Responsibility (lead in bold) Action Existing flood Management and Drainage Strategy (MelbWater, 2007) risk Future flood risk Knowledge Education, base awareness and Responsibilities and whether to protect, adapt or retreat once holistic flood modelling is completed d. Identify, plan and implement flood damages prevention strategies (links closely with CoPP community education program) Note: This action relates to the Climate Adaptation Plan; Update SBOs for Existing Conditions and Flood Damages (including floor level survey), Identification of stormwater reuse and WSUD options, Water Sensitive Urban Design (WSUD) and Update SBOs including allowance for Climate Change actions within Council s Stormwater Action Plan. Flood Management Plan for City of Port Phillip and Melbourne Water 45

51 Linkage to Flood Action Number Issue/Gap Location Priority (L, M, H) Cost impact? Timing Responsibility (lead in bold) Action Existing flood Management and Drainage Strategy (MelbWater, 2007) risk Future flood risk Knowledge Education, base awareness and Responsibilities and 4.2 Underground car parking 14 There is a lack of clear CoPP Medium June CoPP a. Ensure that the design of Y direction on what is required 2012 MW underground car parks in the design of underground VicRoa incorporates measures to protect car parks to protect them from ds them from the risk of flooding floods. from overland flow. b. Once flood modelling is completed, determine if basements will be disallowed in all future developments. 5 Community Education 5.1 Flood warning 15 There is a lack of information CoPP Medium June Vic a. Develop a Flood Education Strategy to Y Y Y on flood risks and advice on 2012 SES increase general community awareness, how to prepare for and CoPP action and resilience during flood events. respond to floods. This may MW Incorporates VICSES Flood Safe and affect community awareness Storm Safe Community Education of the risk and preparedness programs. for flooding. b. Review available flood/inundation scenario mapping and assess vulnerable 46 Flood Management Plan for City of Port Phillip and Melbourne Water

52 Linkage to Flood Action Number Issue/Gap Location Priority (L, M, H) Cost impact? Timing Responsibility (lead in bold) Action Existing flood Management and Drainage Strategy (MelbWater, 2007) risk Future flood risk Knowledge Education, base awareness and Responsibilities and communities under various scenarios. c. Incorporate a Communication Plan that identifies and prioritises target/vulnerable groups, key messages, information products needed and coordination of timely methods of information dissemination in the short and long term d. Implement ongoing community capacity building/education activities. 6 Emergency Planning 6.1 Emergency Protocols 16 Lack of coordination and CoPP Medium June CoPP a. Utilise the best available flood Y Y Y Y awareness of flood information 2012 Vic risk/issue information and knowledge will hinder flood mitigation and SES including hots spots, and mapping and reduce efficiency of responses. future impacts from climate change (eg coastal inundation maps), to develop a Flood Emergency Plan (FEP). Include coordination with Traffic Control Centre. Flood Management Plan for City of Port Phillip and Melbourne Water 47

53 Linkage to Flood Action Number Issue/Gap Location Priority (L, M, H) Cost impact? Timing Responsibility (lead in bold) Action Existing flood Management and Drainage Strategy (MelbWater, 2007) risk Future flood risk Knowledge Education, base awareness and Responsibilities and b. Implement Flood Emergency Plan. Note: This action relates to the Emergency Response Planning action within Council s Stormwater Action Plan. 48 Flood Management Plan for City of Port Phillip and Melbourne Water

54 11 Monitoring and Review This Flood Management Plan is a live document. As such it will need to be reviewed each year to ensure that it continues to accurately reflect flood risks and their treatment within the Municipality as well as prevailing statutory and policy requirements. It should also be revised at least every five (5) years to reflect achievement of work program objectives and changes to work program priorities. While Melbourne Water will assist with the revision process, it will need to be driven and managed by Council. Unless scheduled otherwise, it is suggested that the review and revision processes should occur immediately before the annual budget cycle so that maximum opportunity can be made of available funding sources and processes in partnership with stakeholder entities. Melbourne Water will be responsible for initiating review and updates with the City of Port Phillip. Melbourne Water and City of Port Phillip will track and report to each other on actions in the Improvement Plan on an annual basis. Document control This version Version Number 1 Date March 2012 Frequency of Review Five yearly or earlier as required Next Review Due March 2017 Responsible Officer Erin Davie Team Leader Flood Strategy Implementation Document history Version Date Comments/changes Issue 1, Rev 0 21 June 2010 Draft Plan Issue 1, Rev 1 24 August 2010 Final Draft Plan Issue 1, Rev 2 21 April 2011 Final Plan Issue 1, Rev 3 September 2011 Revised Final Plan Issue 1, Rev 4 14 November 2011 Revised final plan Version 1 22 March 2012 Version 1 Flood Management Plan for City of Port Phillip and Melbourne Water 49

55 12 How this document was developed The Plan was developed through a series of interviews, file reviews, meetings, site visits and workshops, to gather the background information, identify flood risk management and mitigation activities, and arrangements, undertake a gap analysis and develop an improvement plan. This document was developed by the following people: Name Position Organisation Atilio Numa Coordinator Infrastructure Development CoPP Caroline Chandler Senior Sustainable Environment Officer CoPP Clare Gibson Manager Assets CoPP Damien Burgess Manager Infrastructure Services CoPP Darren Findlay Coordinator Beach & Street Cleaning CoPP Darren Martin MERO CoPP David Elson Coordinator Asset Planning CoPP Eli Greig Strategic Planner CoPP Enrique Gutierrez Coordinator Infrastructure Maintenance CoPP John Williams Coordinator Asset Management CoPP Katrina Terjung Coordinator Strategic Planning CoPP Lalitha Ramachandran Senior Project Manager Sustainability CoPP Mohamed El-Saafin Asset Engineer CoPP Peter Jumeau Coordinator Infrastructure Maintenance CoPP Robert Reid Coordinator Operations & Service Delivery CoPP Sam Hewett Manager Property Services & MERO CoPP Sandra Wade Manager City Strategy CoPP Andrew Prout General Manager Victoria EnGenY Brendan Jolly Manager Civil Infrastructure Maintenance Fulton Hogan Bruce Rush Team Leader Town Planning Melbourne Water Denis Bonello Program Leader, Floodplain Mapping Projects Melbourne Water Erin Davie Team Leader Flood Strategy Melbourne Water Keith Boniface Section Leader Investigations and Surveys Melbourne Water Nicole Biscan Flood Strategy Melbourne Water Phillip Neville Manager Floodplain Services Melbourne Water Suresh Bajracharya Water Resources Engineer, Floodplain Services Melbourne Water Gus McEwan Manager Streets Ahead STREETSAHEAD Belinda Lovell Associate Scientist URS Australia David Fuller Senior Principal Water and Catchments URS Australia Melissa Yates Senior Civil Engineer URS Australia Rocco Vivarelli Senior Water Engineer URS Australia John Graves Regional Planning VicRoads Phil Burga Routine Operations and Maintenance VicRoads Alice Godycki Regional Officer Emergency Management Victoria SES Lance Jennison Regional Officer Emergency Management Victoria SES Mark Wetteland Regional Officer Emergency Management Victoria SES 50 Flood Management Plan for City of Port Phillip and Melbourne Water

56 13 Acknowledgements Melbourne Water acknowledges the contribution of employees of City of Port Phillip, VICSES, VicRoads and the URS project team, in preparing this plan. Flood Management Plan for City of Port Phillip and Melbourne Water 51

57 ABBREVIATIONS & ACRONYMS The following abbreviations and acronyms are used in this Flood Management Plan: AEP ARI CEO DSE MEMP MERO PMF SBO VICSES WSUD Annual Exceedence Probability Average Recurrence Interval Chief Executive Officer Department of Sustainability and Environment (successor body to DNRE) Municipal Emergency Management Plan Municipal Emergency Resource Officer Probable Maximum Flood Special Building Overlay Victoria State Emergency Service Water Sensitive Urban design 52 Flood Management Plan for City of Port Phillip and Melbourne Water

58 REFERENCES ABS (Australian Bureau of Statistics) (2006): Census of Population and Housing. Auditor General Victoria: Managing Stormwater Flooding Risks in Melbourne. Australian Parliament (1955): Meteorological Act 1955 Australian Parliament (2007): Water Act 2007 City of Port Phillip (1999), prepared by Fisher Stewart: St Kilda Drainage Study. City of Port Phillip (2002), prepared by Hyder: South Melbourne Drainage Study. City of Port Phillip (1998), prepared by GHD: Port Phillip Flood Mapping Study. City of Port Phillip (1999), prepared by Fisher Stewart: Port Phillip Drainage Improvement Program. City of Port Phillip (2007), prepared by NATCLIM: Planning For Climate Change. City of Port Phillip (2009), prepared by URS Australia: Stormwater Action Plan. City of Port Phillip (1999), prepared by Australian Water Technologies: The Surface Water Management Plan City of Port Phillip: Draft Open Space Water Management Plan City of Port Phillip (2009): Draft Water Plan, Toward a Water Sensitive City City of Port Phillip (2010): Municipal Emergency Management Plan City of Port Phillip (2010): Climate Adaptation Plan Climate Adept City CSIRO (2009): The Effect of Climate Change on Extreme Sea Levels in Port Phillip Bay, a project undertaken for the Department of Sustainability and the Environment. DSE (2010): A Guide for Coastal Floodplan Management Authorities: Assessing development in coastal flood risk areas (DRAFT) DSE: Climate Change in Port Phillip and Westernport and Victoria Drainage Strategy DSE (2008): Victorian Coastal Strategy 53 Flood Management Plan for City of Port Phillip and Melbourne Water

59 Melbourne Water (2010): Planning for sea level rise, Interim guidelines Assessing development in areas prone to tidal inundation from sea level rise in the Port Phillip and Westernport Region Melbourne Water (2009a): Flood Risk Assessment Framework. Melbourne Water (2009c): Land Development Manual. Melbourne Water (2008): Water Industry Act 1994 Melbourne Water Corporation Statement of Obligations Melbourne Water (2007a): Port Phillip and Westernport Region Flood Management and Drainage Strategy, November Melbourne Water (2007b): Principles for Provision of Waterway and Drainage Services for Urban Growth. Melbourne Water (2004): Melbourne s Rivers and Creeks. Melbourne Water, Bass Coast Shire Council, Baw Baw Shire Council, Cardinia Shire Council, Mornington Peninsula Shire Council and South Gippsland Shire Council (2009): Water Sensitive Urban Design Guidelines. Melbourne Water (2005): Elster Creek Catchment Study Melbourne Water (2005): Flood Management Drainage Strategy Part 1, 2, 3 and 4 SCARM (2000) Floodplain Management in Australia: Best Practice Principles and Guidelines Victorian Parliament (2005): Victorian State Emergency Services Act 2005 Victorian Parliament (1994): Water Industry Act 1994 Victorian Parliament (1989): Water Act 1989 Victorian Parliament (1989): Local Government Act 1989 Victorian Parliament (1986): Emergency Management Act Flood Management Plan for City of Port Phillip and Melbourne Water

60 APPENDIX A ROLES AND RESPONSIBILITIES A large number of organisations at different levels are directly involved in managing various aspects of flooding within Victoria, as set out in the table below (as at June 2010). Level Organisation Core role National Bureau of Meteorology Dept of Transport & Regional Services Emergency Management Australia Department of Social Security Flood forecast and warning Warnings of weather conditions likely to cause flash flooding Water information Climate data and prediction Financial assistance for planning, warning & mitigation initiatives Emergency management planning and coordination Financial and other support services for affected areas State of Victoria Victoria Police Victoria State Emergency Service Department of Human Services Environment Protection Authority Department of Sustainability & Environment Department of Planning and Community Regional emergency planning and response coordination Responsible for flood response as well as assisting council with their Municipal Emergency Management Planning, can assist council with education, awareness, warning systems and emergency management planning. Impart expertise in emergency recovery management, and can assist with the development of Municipal Emergency Management Plans and public health sub plans. Assess environmental impact of flood emergencies Has the primary responsibility for the development of strategies and policy in relation to flood and stormwater management at a statewide level Land use and development policy 55 Flood Management Plan for City of Port Phillip and Melbourne Water

61 Level Organisation Core role Development Department of Justice State-wide Emergency Management Policy Financial assistance and grants for those affected by flooding Regional Melbourne Water VicRoads Primary responsibility for identification of flood extents, providing flood warning advice for major waterways, controlling development in floodplains, providing advice on flooding to local councils and the community, developing plans, and undertaking actions to minimise flooding and flood damage in the Port Phillip and Westernport region. Drainage for major arterial roads Emergency response Local City of Port Phillip Establish and maintain a Planning Scheme that includes relevant flood provisions (i.e. administer and enforce planning provisions and building regulations for flood affected land) Manage flooding issues to reduce risks and impacts Ensure flood information is available to inform decisions Manage local urban (street and property) and upstream drainage Management of open spaces along waterway corridors Maintain and enhance local flood information Develop and implement flood emergency response plans Support community education and awareness on flood risks 56 Flood Management Plan for City of Port Phillip and Melbourne Water

62 Primary and secondary responsibilities in delivery of flood management State Legislature State Treasury Department of Sustainability and Environment Regional Floodplain Authority Local Council VICSES Bureau of Meteorology Department Justice / Vic Police Department Human Services Department of Planning and Community Development Building Commission Other institutions and the community Address legal / institutional gaps Analyse and map flood risks Publish flood risk details Provide flood intelligence data Implement development controls Education and awareness Contingency planning Flood warnings and alerts Emergency response Smart urban renewal Runoff reduction 57 Flood Management Plan for City of Port Phillip and Melbourne Water

63 APPENDIX B - FLOOD RISK ASSESSMENT Below is the risk assessment matrix result for this municipality, by catchment, from the Melbourne Water Flood Risk Assessment Framework and Matrix, noting the catchments with medium, high or extreme ( intolerable ) risk rating. Projects to mitigate flood risk will need to be categorised, discussed and prioritised with due consideration of Council and Melbourne Water priorities, aims, work programs and targets - in other words a program needs to be developed for their implementation. The resulting program will need to also recognise residual risks and propose management measures that are likely to include improved community awareness, flood response planning and preparedness. Any proposed land use planning or controls to be implemented or investigated should be included in the program. Table B-1 Flood Risk Matrix Results for City of Port Phillip Source: Melbourne Water Flood Risk Matrix 2010 Catchment name ELWOOD CANAL (including Koornang, Caulfield, Moorabbin SHAKESPEARE GROVE M.D. COWDEROY STREET M.D. HANNA STREET MD # commercial/ industrial properties within 1% AEP flood extent # residential properties within 1% AEP flood extent # properties total Risk score (out of 10) Risk rating (medium, high, extreme) Extreme Extreme High High PRINCES STREET M D Medium ROSNY STREET M.D Medium 58 Flood Management Plan for City of Port Phillip and Melbourne Water

64 Figure B-1 Map of 100 year ARI flood extent showing catchment areas, colour coded by risk level 59 Flood Management Plan for City of Port Phillip and Melbourne Water

65 Figure B-2 Localised map of the extreme flood risk catchments Elwood Canal 60 Flood Management Plan for City of Port Phillip and Melbourne Water

66 Figure B-3 Localised map of the extreme flood risk catchments Shakespeare Grove Main Drain 61 Flood Management Plan for City of Port Phillip and Melbourne Water

67 APPENDIX C DATA, DRAINAGE SYSTEM UPGRADES & STUDIES Table C-1 Available GIS DATA CoPP boundary MW catchment boundary Coastline Major catchment Primary catchments River basin catchments Channel structures and node Melbourne Water Drains catchment Drains underground structures and nodes Channel centreline and alignment Drains alignment Waterways centreline and alignment Natural wetlands Water bodies Council drainage network all pipes and pits Retarding basins RORB Nodes, Reach alignments, catchment boundaries, sub catchment boundaries for Essex Street Main Drain, Beatty Avenue Main Drain, RORB Nodes, Reach alignments, catchment boundaries, sub catchment boundaries for Elwood Canal, Byron St Main Drain, Elsternwick Main Drain, Elwood Diversion Drain, Meek Street Drain Cadastre Properties Roads names and alignments Street numbers Aerial photos of the catchment LIDAR Sub 1m, 1m, 5m and 20m contours Planning scheme zones Heritage overlay Public acquisition overlay Port Phillip 500m buffer 100 year flood extent waterways 100 year flood extend underground drains Areas not flood mapped Port Phillip special building overlay Land subject to inundation overlay Ind value with risk rating Tidal Inundation Current: 1.6m Tidal Inundation Future: 2.4m Tidal Inundation Future + Freeboard: 3.0m 62 Flood Management Plan for City of Port Phillip and Melbourne Water

68 CITY OF PORT PHILLIP STUDIES Between 1999 and 2002 three major drainage studies based on the pre-amalgamation Council areas were completed. The studies focused on the capacity of Council s underground drains to contain the stated service level of a 5 year ARI rain event. These studies also included survey and mapping of Councils underground drainage system. Not all drain details were able to be obtained due to factors including tide levels, drain blockages and the building over of drainage pit covers. Study: St Kilda Drainage Study 1999 Fisher Stewart May 1999 (Volume 1: Drainage Improvement Plan) (Volume 2: Modelling Results for Existing Conditions and Optional Upgrades) (Volume 3: Maps Folder and CD) Purpose/Aim: Drainage Study of the St Kilda Catchment. Identify all catchments, conduct field surveys and produce record plans of the existing stormwater system; Analyse and identify capacities, limitations and inadequacies of the existing systems; Make recommendations which will minimise road flooding and property damage within the neighbourhood and surrounding districts and to upgrade the stormwater drainage system, including the design of drainage systems; and Compile a prioritised listing and associated cost estimates for implementation of the recommendations. Methodology: Catchment modelled using HydroWorks and InfoWorks. Fifteen sub-catchments were identified for analysis. Each of these was modelled using HydroWorks. Synthetic storm events with an average return period of 1 in 5 years and of varying durations were routed through each catchment to determine the critical storm duration. Each system was then analysed to determine the pipes unable to contain the design storm runoff. Survey information was entered into an electronic database ready for production of maps. The property boundary fences were assumed to coincide with the cadastral base provided by the City of Port Phillip. Connectivity, grades and diameters were checked using InfoWorks. Once satisfied that the drainage network information was complete the catchment areas were delineated. Calculation of the contributing areas for the St Kilda catchments was undertaken using Info Works. The cadastral background (obtained from the CPP) was imported and overlain with the drainage model. Areas were delineated, based on the slope of the catchment, for all points of entry to the system. Data Used: Asset data - Field surveys and CPP drainage plans Cadastral background CPP Hydraulic roughness of pipes CPP 63 Flood Management Plan for City of Port Phillip and Melbourne Water

69 CITY OF PORT PHILLIP STUDIES Design Rainfall Australian Rainfall & Runoff Vol I and I Land Use - Field observations Percentage impervious/pervious - Standard values from Fisher Stewart Contributing areas - Calculated in Info Works Runoff routing coefficients - Wallingford procedure empirically based values Melbourne Water main drain plans - Melbourne Water Assumptions: Upgrades to network only. Spill Volume not rerouted. It was assumed all upgrades undertaken during the option analysis phase were on-line replacements. ie. No duplication and no major re-arrangement of the network by cross linking, except in rare cases. Only drains experiencing flooding were assumed to warrant upgrading Colebrook-White roughness of O.6mm for bottom of pipe and O.3mm for top of pipe was globally assumed for the St Kilda drainage system. No attempt made to route the spill volume through the system as this was outside the scope of the project. The model simplistically allows for the spill volume to re-enter the system when the hydraulic grade line recedes and capacity exists. Area Covered: St Kilda Catchment The St Kilda Catchment lies within the borders of the City of Port Phillip and covers an approximate area of 800 Ha. The catchment is predominantly residential. Overall, approximately 10% has been identified as commercial which has also been assumed to include industrial areas. Outcomes / Recommendations: Total required upgrade works exceed $8.6 million. Priority list of works provided in report. Plans showing the upgrading works are contained in Volume 3 - Map Folder. It was recommended that further work be undertaken to enhance the priority setting basis including works from Port Melbourne. Project Deliverables: Report on field survey methodology; Digital copy (MapInfo format) of all field survey data and subsequent assumptions made at the data capture stage. A full listing of the fields supplied has been included in Volume 1; Hard copy coloured catchment plans for the existing conditions of each drainage sub catchment at a scale of 1: (3 copies); Report on design parameters used in the modelling process; Costed and prioritised improvement works program for the drainage system; and Hard copy drainage improvement plans (1 copy). 64 Flood Management Plan for City of Port Phillip and Melbourne Water

70 CITY OF PORT PHILLIP STUDIES Maps Available:..\8 Refs\Maps\St Kilda Drainage Study 1999 Catchment Plan for Existing Stormwater Drainage Plans.pdf Additional Information Required: Volume 3: Maps Folder and CD. Study: South Melbourne Drainage Study 2002 Hyder February 2002 Purpose/Aim: Identify catchments in the neighbourhood Develop a map base including field survey of all existing drainage information, levels and development of plans Analyse and identify pipe capacities, limitations and inadequacies of the existing drainage network Make recommendations within the neighbourhood to minimise road flooding and property damage Compile a Priority List of recommended works throughout the study area Methodology: Catchment modelled using Drains and 4D. Hyder undertook a detailed analysis of the Council drainage system in the City of Port Phillip. The broad outline of the tasks cared out is described below. 1. Receive drainage network data from surveyor 3. Convert entire drainage network from spreadsheet into the format required by 4D using customised macro. 5. Divide drainage network model in 4D into separate models for each main catchment. 7. Export 4D catchment plans into AutoCAD and plot catchments and catchment labels. 8. Export 4D drainage network models into a spreadsheet for transfer into DRAINS software. 9. Add information into the spreadsheet created above, including missing invert levels and cover levels, standardising pipe sizes, pipe types and pit types. 11. Create a drainage network fie in DRAINS from the spreadsheet with pipe and pit data for each catchment for this project. 13. Analyse existing network in DRAINS. 14. Determine pipe size upgrades in DRAINS 15. Prepare drainage upgrade plans (using Microstation) showing existing and proposed pipe sizes. 16. Prepare priority listing on Excel, detailing the extent of recommended pipe upgrades and an estimated cost. Data Used: - Assumptions: Values of pipe roughness as agreed with Council: Manning s n = Colebrook-White ks = 0.15 mm Area Covered: - 65 Flood Management Plan for City of Port Phillip and Melbourne Water

71 CITY OF PORT PHILLIP STUDIES Outcomes / Recommendations: A total of approximately $28 Million of drainage improvement works is required to ensure the South Melbourne drainage network has the capacity to pipe the 5 year AR storm event. Table 6.1 from report, page 30. Project Deliverables: Report Priority Listing of all recommended works A1 colour plans of the municipality highlighting the recommended works Colour catchment plans DRAINS output plans including pit and flow information Digital copies of all outputs Maps Available: None Provided Additional Information Required: Appendix B - SeparateA3 Report Titled "South Melbourne Drainage Study, Priority Lists" Appendix G Recommended Works Plans" Study: Port Phillip Drainage Improvement Program, CoPP 1999 Fisher Stewart January 1999 (Superseded) Purpose/Aim: Provide a prioritised and costed drainage improvement program for Port Melbourne. The report has been provided to assist the City of Port Philip (CPP) undertake capital planning for 1999/2000 and beyond Methodology: A comparison of predicted capacity against a 1 in 5 year design storm for residential areas and a 1 in 10 year design storm for industrial areas has been included. All pipes showing surcharge as a result of the design storm, and all pits experiencing overflow have been identified. The total spill for each catchment has been estimated. In an attempt to eliminate all flooding under the design storm, pipe upgrades have been adopted and the drainage network remodelled. All works have been costed using a defined cost model previously approved by council, and a works priority has been provided using a simple cost/benefit model which ignores non flooding factors such as location, accessibility, community disruption, further urban development etc Data Used: Upgrades to network only. Spill Volume not rerouted. It was assumed all upgrades undertaken during the option analysis phase were on-line replacements. ie. No duplication and no major re-arrangement of the network by cross linking, except in rare cases. Only drains experiencing flooding were assumed to warrant upgrading No attempt made to route the spill volume through the system as this was outside the scope of the project. The model simplistically allows for the spill volume to re-enter the system when the hydraulic grade line recedes and capacity exists 66 Flood Management Plan for City of Port Phillip and Melbourne Water

72 CITY OF PORT PHILLIP STUDIES Area Covered: Hydraulic analysis of all drains in Port Melbourne. Detailed outcomes provided, however, need data to match node numbers to geographical locations Maps Available:..\8 Refs\Maps\Port Melbourne Drainage Improvement Program 1999 Catchment Areas.pdf Geographical reference of model nodes required. Study: Port Phillip Drainage Improvement Program, CoPP 1999 Fisher Stewart January 1999 (Superseded) Purpose/Aim: Provide a prioritised and costed drainage improvement program for Port Melbourne. The report has been provided to assist the City of Port Philip (CPP) undertake capital planning for 1999/2000 and beyond. Methodology: A comparison of predicted capacity against a 1 in 5 year design storm for residential areas and a 1 in 10 year design storm for industrial areas has been included. All pipes showing surcharge as a result of the design storm, and all pits experiencing overflow have been identified. The total spill for each catchment has been estimated. In an attempt to eliminate all flooding under the design storm, pipe upgrades have been adopted and the drainage network remodelled. All works have been costed using a defined cost model previously approved by council, and a works priority has been provided using a simple cost/benefit model which ignores non flooding factors such as location, accessibility, community disruption, further urban development etc. Assumptions: Upgrades to network only. Spill Volume not rerouted. It was assumed all upgrades undertaken during the option analysis phase were on-line replacements. ie. No duplication and no major re-arrangement of the network by cross linking, except in rare cases. Only drains experiencing flooding were assumed to warrant upgrading No attempt made to route the spill volume through the system as this was outside the scope of the project. The model simplistically allows for the spill volume to re-enter the system when the hydraulic grade line recedes and capacity exists. Area Covered: Hydraulic analysis of all drains in Port Melbourne. Outcomes / Recommendations: Detailed outcomes provided, however, need data to match node numbers to geographical locations. Maps Available:..\8 Refs\Maps\Port Melbourne Drainage Improvement Program 1999 Catchment Areas.pdf Additional Information Required: Geographical reference of model nodes required. Maps Study: Planning For Climate Change, 2007 NATCLIM 2007 NATCLIM conducted a detailed climate change risk assessment of part of St. Kilda, which is applied in this study to assist with future planning for climate change in the City of Port Phillip. The report also provides detailed mapping of at risk areas and lists prioritised recommendations for the necessary next steps. By anticipating potential climate change issues and adapting 67 Flood Management Plan for City of Port Phillip and Melbourne Water

73 CITY OF PORT PHILLIP STUDIES accordingly, City of Port Phillip is actively reducing its vulnerability to climate change. Purpose/Aim: Toward Zero: Sustainability Strategy Assist with future planning for climate change in the City of Port Phillip. The purpose of climate risk management and mitigation measures is to minimise identified risks by decreasing their overall risk scores. Therefore, measures are designed to decrease the likelihood of a potential risk occurring and / or to decrease the magnitude of the consequence should a risk occur. Methodology: Australian Standard, AS/NZS 4360:1999, and Methodology outlined in Climate Change Impacts and Risk Management: a Guide for Business and Government Data Used: Risk assessment based on climate data available at the time of the report and as referenced in the report. Climate Variables Studied Include: Temperatures (higher mean/maximum & extreme) Intense rainfall Lightening Wind Heatwaves Higher potential evaporation Wind gusts / wind speed Hail storms Storm surge Decreased annual rainfall Sea level rise Cold snap Assumptions: Climate data available at the time of the report and as referenced in the report. Area Covered: City of Port Phillip Including: - The St Kilda Foreshore including the Pier and St Kilda beach - Luna Park - St Kilda Botanic Gardens - The Esplanade - Catani Gardens - St Kilda Marina - Fitzroy and Acland Streets - Ormond Village Outcomes / Recommendations: The climate change risk assessment systematically identified the potential risks associated with changes to a range of climate Variables and provided a list of methods to management / reduce the risk of each risk. Project Deliverables: Recommended Risk Management Measures: 1. Create a Risk Assessment Tool 2. Create a Planning Tool 3. Create an Infrastructure Management Tool 4. Improve Data & Systems 5. Adapt Community Enabling/Emergency Services 6. Build Staff Capacity 7. Advocate at the Community, State and Regional Level 8. Collaborate with External Stakeholders Maps Available: At risk areas (Maps not displayed in provided report, sheets left blank where figure should be) Additional Information Required: Maps not displayed in provided report, sheets left blank where figure should be Study: Stormwater Action Plan URS Australia Flood Management Plan for City of Port Phillip and Melbourne Water

74 CITY OF PORT PHILLIP STUDIES Purpose/Aim: The purpose to the Stormwater Action Plan is to create Council Actions for managing flooding risks and the Council drainage system. Methodology: Review the existing information, workshop with staff regarding the current issues and gaps, assess and prioritise tasks and produce an action plan that documents an agreed approach to a project to update flood mapping and drainage risk assessments across the City of Port Phillip. Data Used: Previous reports (998 to present) from DSE, City or Port Phillip, Auditor General and Melbourne Water. Assumptions: Data available at the time of the report and as referenced in the report. Area Covered: The entire catchment of the city of Port Phillip Outcomes / Recommendations: A table of all the actions identified during workshop with the different departments of the City of Port Phillip. It details each action by: -Description -Benefits to City of Port Phillip -Benefits to subsequent actions Cost Actions are prioritised Project Deliverables: - Data Review - Identification of Issues - Identification of Actions Prioritisation Implementation Study: Stormwater Management Plan for the City of Port Philip Australian Water Technologies in 1999 The plan provided a direction for the environmental management of stormwater within Port Phillip. The plan also presented an integrated approach to stormwater management, which maintains the traditional function of preventing adverse flooding, but also places emphasis on improving water quality and environmental amenity of stormwater systems. Other related documents Draft Open Space Water Management Plan Draft Water Plan, Toward a Water Sensitive city 2009 Municipal Emergency Management Plan 2010 Draft Climate Adaptation Plan Climate Adept City Melbourne Water Study: Elster Creek Catchment Study, CoPP 2005 Purpose/Aim: To treat stormwater flows in Elster Creek Catchment Investigation into structural opportunities to treat stormwater from Elster Creek and Elwood Canal and the associated economic costs Methodology: Phase 1: Preliminary Activities Phase 2: Assessment of pollutant types and loads (incl proposed development) 69 Flood Management Plan for City of Port Phillip and Melbourne Water

75 Phase 3: Water Quality Issue Assessment Phase 4: Treatment Train Solutions and Options Phase 5: Reporting MUSIC Modelling Data Used: Construction cost estimates Water quality sampling results Assumptions: Future residential development planning information. Land use type mapping. Area Covered: Eslter Creek Catchment Area Outcomes / Recommendations: WSUD practical implementation layout and associated costs. Project Deliverables: Water quality treatment plan and prioritised allocation of funding for stormwater treatment measures Maps Available: Existing land use Proposed water quality treatment locations Study: Flood Management Drainage Strategy, Melbourne Water (and others) 2007 Part 1 Purpose/Aim: How to improve the management of flood risk in the Port Phillip and Westernport Region. Long term aim is to minimise all currently known intolerable flooding risks to public health and safety, property and infrastructure, and increase community understanding and preparedness for floods Melbourne Water will continue to map flood affected areas and will sponsor research into the intangible social and human health impacts of floods, to develop an improved flood risk assessment tool that takes these costs into account when determining flood risk priorities and responses Methodology: 5 Flood Management Objectives: 1. Completing the knowledge base 2. Potential long-term future pressures on existing drainage systems 3. An agreed approach to managing existing regional flooding problems 4. Enhanced community education, flood awareness and preparation 5. Agreed responsibilities and improved collaboration between flood management agencies Data Used: Annual Exceedence Probability (AEP) Average Recurrence Interval (ARI) Part 2 Purpose/Aim: Education History / Overview of flooding in Port Phillip and Westernport Region 70 Flood Management Plan for City of Port Phillip and Melbourne Water

76 Methodology: History of flooding Estimation of damage Economic impact Identification of flood management authorities Description of shared responsibilities Data Used: Economic: 1 Report 103 Economic Costs of Natural Disasters in Australia, Bureau of Transport and Regional Economics (2001) Part 3 Purpose/Aim: Description of the proposed methodology to achieve Flood Management Objectives 1-3, as listed in Part 1 Methodology: List of 1-3 of Melbourne Waters 5 Flood Management Objectives and their associated social impacts, challenged and actions Data Used: Intergovernmental Panel on Climate Change s Fourth Assessment Report 2007 Melbourne Water Climate Change Study Implications of Potential Climate Change for Melbourne s Water Resources (2005), CSIRO Part 4 Purpose/Aim: Description of the proposed methodology to achieve Flood Management Objectives 4-5, as listed in Part 1 Methodology: List of 4-5 of Melbourne Waters 5 Flood Management Objectives and their associated social impacts, challenged and actions Assumptions: Assumed climate forecasts are accurate Area Covered: Port Phillip and Westernport Region Maps Available: Some schematic diagrams and supporting graphs. Outcomes / Recommendations: Flood management framework for authorities Auditor General, Victoria Study: Managing Stormwater Flooding Risks in Melbourne The Auditor General s report on Managing Stormwater Flooding Risks in Melbourne identifies that metropolitan Melbourne continues to be exposed to the risks of significant flood related damage from significant storm events. Reducing this exposure will require a range of responses from improving community education, upgrading drainage systems, introducing better planning controls and addressing legislative gaps. The report highlights that the Department of Sustainability, Melbourne Water Corporation and local government need to work collaboratively to raise stormwater flood protection levels for 71 Flood Management Plan for City of Port Phillip and Melbourne Water

77 metropolitan Melbourne. This review identified the need for all local Councils to have programs in place to manage urban flooding risks for their drainage systems through a combination of structural and non structural programs. DSE Study: Climate Change in Port Phillip and Westernport And Victoria Drainage Strategy DSE is the Victorian State Government Department that advises the Victorian Water Minister. DSE is therefore interested in a range of issues that relate to drainage and flooding in all of Victoria, including the City of Port Phillip. Two key projects for DSE at the moment are likely to impact on the actions of the City of Port Phillip: Climate change impact studies on rainfall and sea levels (with input from CSIRO and Bureau of Meteorology). Victorian Drainage Strategy. The Climate Change in Port Phillip and Westernport document is a summary of how the climate change of Port Phillip and Westernport is expected to change during the 21st century based on a range of greenhouse gas emissions scenarios (a copy of this document has been previously provided). Heavy rainfall intensity for Melbourne is projected to change from -50.6% to 73.4%. Global sea levels are projected to rise between 0.18 to 0.59m by 2095, with a possible additional contribution from ice sheet melts of 0.1 to 0.2m. The Victorian Drainage Strategy is still being prepared by DSE. Some consultation has occurred with various organisations and individuals and a draft report is expected to be released once the draft is ready for external release. Study: Victorian Coastal Strategy 2008 The Victorian Coastal Council released the most recent Victorian Coastal Strategy in This strategy aims to guide policy and actions in a range of coastal management issues. One of the most significant risks to the Victorian Coast is climate change which has the potential to cause increased coastal flooding as well as other impacts such as increased coastal erosion and damage to infrastructure. The Victorian Coastal Strategy, 2008 discusses approaches to manage climate change predictions of increases in sea level as per the following excerpt from the Victorian Coastal Council s website ( 72 Flood Management Plan for City of Port Phillip and Melbourne Water

78 APPENDIX D FLOOD HOT SPOTS LIST AND MAP Figure D-1 Drainage Problems 73 Flood Management Plan for City of Port Phillip and Melbourne Water

79 Figure D-2 Flooding Problems 74 Flood Management Plan for City of Port Phillip and Melbourne Water

80 Table D-3 Flood Hot Spots List 75 Flood Management Plan for City of Port Phillip and Melbourne Water

81 Figure D-3 Flood Hot Spots Map These notes have been developed from opinions expressed at a workshop (Workshop #1, 17th May 2010, between City of Port Phillip, Victorian SES, Melbourne Water, URS, EnGenY) and a meeting held with the City of Port Phillip maintenance crew (organised by Gus McEwan with EnGenY, 4 June 2010). Number Location Main Comment Cause A=Tidal B= Blockage/ Poor infrastruc ture C= Intense rain 1 Pier Street B (No outlet) Pipe doesn t have an outlet, unfinished pipe construction. Frequently floods, whenever it rains, street/gutter flooding. High rise complex of flat gets into car parks and almost into building. 2 Corner of Reserve B Tree root problems, currently 2 small pipes, possibly one bigger pipe could be constructed. Floods with heavier rains, depends on how often roots cleaned. 3 Blessington/ Marine Parade A Sand tidal. David Elson at Council aware of this, new access pit to be constructed. Underground car park flooded, severe flooding in road-over the footpath. Jan herald sun photo, significant flooding into buildings, cars were floating. URS flood mapping and options report done in Edwards Avenue B Buried pit, soil/tree debris/branches. Getting fixed near future. Contained in street with wide footpath. 5 Walter Street B Blockage, tree roots. Cleaned and performing better. Street flooding (heavily traffic road so not good to have this amount of flooding in the street) 6 Gladstone Lane/Montague St A Tidal, frequently street flooding lane always muddy looking. Cars can t park in lane and cars getting damaged and wet, flooding getting into buildings. 6A Montague St B Blockage over grates, underpass. Noted at 76 Flood Management Plan for City of Port Phillip and Melbourne Water

82 Number Location Main Comment Cause A=Tidal B= Blockage/ Poor infrastruc ture C= Intense rain Underpass workshop #1. Quite deep water ponds in underpass particularly in intense short duration rainfall. Flooding affects traffic. Problems investigated over last 10 years and concept design options and cost estimates considered by Council. 7 Johnston/ Munro A Heavy rain, water can t get into pipe. Internal building flooding as downpipes can t discharge into street drain. Occurs when high tide and high rainfall. Tidal mud/debris pushed up pipe. 8 Post Office Place A Flooding of inside road lane, flooding usually contained in road. Haven t been able to access pit not sure where pipe goes, some sand in the pipe. 9 Bay Street B Needs regular jetting as a result of debris big litter problem from shops. Both sides of road flooded, flooding contained within the street. 10 Albert/Ferrars Place B Water ponding can t get away due to tree roots. Car damage with cars parked on the street. 11 York Street B Debris blockage over grates, underpass. Noted at workshop #1. Quite deep water ponds in underpass particularly in intense short duration rainfall. Flooding affects traffic. 12 Dorcas St/Kings Way B Blocked pit, small pipes within pit easily blocked. 13 Kings Way C (March 2010) Cars flooded. Houses and shops flooding up to door and inside in some instances as a result of intense rain. 14 Kings Way C (March 2010) Street flooding as a result of intense rain. 15 Town Bay Street B Angled outlet pipes in pit get blocked. Flooding up to footpath, people can t walk past the town hall. 77 Flood Management Plan for City of Port Phillip and Melbourne Water

83 Number Location Main Comment Cause A=Tidal B= Blockage/ Poor infrastruc ture C= Intense rain 16 St Kilda Road B Problem with tree roots. Preventative maintenance problem is very active at this location. Flooding particularly at one pit, flooding within the street. 17 Albert Road B Broken pipe. Flooding at the corner, car parking bays affected. 18 Albert Road B Dirt Road causes blockage through dirt/debris. Flooding within the street. 19 Albert Road B Historical problems with tree roots. Has been fixed and no recorded problems since. 20 Roy Street B Poor infrastructure/blockage. Street flooding, flooding in not particularly heavy rain. Frequent nuisance flooding, numerous complaints. 21 Armstrong/ Richardson St B Tree roots problems. Flooding onto the footpath, takes a decent rain for flooding to occur. 22 Mills Street A Street car parks flooded. Good sized pipes with capacity exist at this location. May need to check capacity from previous drainage study. 23 Beach side of Beaconsfield B Insufficient pits at low points. Bumpy road and water collects in low points. Parade 24 St Kilda Rd/Union Rd B Inbound pipe is broken and collapsed causing street flooding. Outbound pipe is blocked by litter and debris, commonly blocked resulted in flooding in some properties. In workshop #1 noted that MW drain under capacity. 25 Raleigh/St Kilda Rd B Problem with blockage due to tree roots. Flooding contained within the street. 26 Union/Queen B Mud/litter causing blockage. Flooding within the street, flooding occurring less than in the past. 27 Acland/Carlisle B McDonald s side of roundabout, people find it 78 Flood Management Plan for City of Port Phillip and Melbourne Water

84 Number Location Main Cause A=Tidal B= Blockage/ Poor infrastruc ture C= Intense rain Comment hard to walk across the road when it floods. Palm tree roots cause blockage. 28 Dickens St A Similar to Blessington/Marine, affected by tidal influence. Maintenance crew not sure where pipe goes. 29 Kingsley St B Difficult access to pit for cleaning. Fear of losing equipment and getting stuck in pipe. Street flooding, into property but not buildings. 30 Foam St B Thick reeds in MW waterway (Elwood Canal) contribute to blockage risk at drainage pipe outlets. 31 Elwood Canal A,C Flooding at streets discharging into canal, flooding is irregular, one street floods in one storm but not in next storm. Dictated by tide, regular flooding not significant and the area is a flood zone. 32 Canterbury Rd B Problems with concrete tree bases holding back flow. Flooding contained within street. 33 Stuart St B Stuart St pit blockage, problem beside building in walkway. Has been identified to be fixed. 34 Cowderoy St - On workshop map but no known problems in a long time. Flood overlay and recent repairs discussed at Workshop #1. 35 Beacon Cove (Princes St to Beach Rd) B,C On workshop map. Historical problems along Beach Road. Improvements have been made over time. Starting to get problems due to tree roots as trees establish themselves in new developments. 36 Gladstone/ Ferrars St A On workshop map, maintenance crew haven t seen flooding for a long time, improvements made due to development in South Wharf area. 79 Flood Management Plan for City of Port Phillip and Melbourne Water

85 80 Flood Management Plan for City of Port Phillip and Melbourne Water

86

87 Draft Flood Management Strategy Port Phillip and Westernport

88 This strategy reflects the work and expertise of floodplain managers across the region. Melbourne Water prepared this strategy with governance and oversight from a Project Control Board representing key stakeholders. ACKNOWLEDGEMENTS Our Flood Strategy Project Control Board included representatives from: Bureau of Meteorology City of Kingston City of Melbourne City West Water Department of Environment, Land, Water and Planning Department of Health and Human Services Emergency Management Commissioner (Chair) Insurance Council of Australia Melbourne Water Metropolitan Planning Authority Municipal Association of Victoria South East Water Victoria State Emergency Service Wyndham City Council Melbourne Water thanks everyone for their involvement; it means we now share a vision and an understanding of the challenges facing our region and the best ways to address them.

89 Contents PREFACE 2 SECTION 1 Introduction 3 Why we need a flood strategy 3 About the Port Phillip and Westernport region 5 Building on progress so far 6 SECTION 2 A shared vision for Port Phillip and Westernport 7 Targets 8 SECTION 3 Flooding in our region 10 The impact of floods 11 Managing large and small floods 16 How flooding is managed 18 Who participates in floodplain management? 19 SECTION 4 Objectives, targets and actions 20 Understanding the risk and sharing information 21 Taking action to manage current and future risks 27 Working together to improve our effectiveness 34 SECTION 5 Delivering this strategy 36 Review process 36 Endorsement and participation 37 Oversight 37 Monitoring and reporting 37 Implementation 37 APPENDIX 1 Flood management roles 38 GLOSSARY 40 ACRONYMS 42 BIBLIOGRAPHY 42 Draft Flood Management Strategy Port Phillip and Westernport 1

90 Preface Melbourne Water prepared this draft strategy by consulting widely. Consultation included discussions and workshops with many stakeholders including state government departments, councils, emergency service organisations, and communities. Most government agencies with a role in flood management for the Port Phillip and Westernport region contributed their expertise. This strategy reflects the effort and activities of floodplain managers across the region.(throughout this strategy we refers to all relevant flood management agencies.) Your feedback on this draft including our proposed direction, actions and targets, will inform development of a final strategy. Research Testing key directions Draft strategy Final strategy CONSULTATION 2 Draft Flood Management Strategy Port Phillip and Westernport

91 Floodwater is dangerous never drive, walk or ride through floodwater. SECTION 1 Introduction Why we need a flood strategy Flooding is natural and inevitable. Like fire and other natural hazards, it is a part of the Australian landscape. Floods are a natural occurrence in the Port Phillip and Westernport Region. We can t stop them happening, but we can plan for and manage the risk. This strategy sets out how we will work to understand, avoid and reduce flood risks, and how we can support flood-emergency preparation and response, across the region. It sets out a vision for the Port Phillip and Westernport region, and creates a framework to help guide the work of the many organisations managing flood risks to deliver on this vision. This strategy will inform current and future approaches to research, flood planning and investment, and engaging with communities. While this strategy discusses all aspects of flooding in our region, its key focus is flood prevention and risk-reduction activities. These are often referred to as floodplain management. These activities support other aspects of general flood management including emergency response and recovery, and planning for natural environments and liveability. This strategy is part of the Victorian all hazards, all agencies approach to emergency risk assessment, prevention, preparedness, response and recovery. Draft Flood Management Strategy Port Phillip and Westernport 3

92 The focus of this flood management strategy RESPONSE Personal response plans Sandbagging Monitoring Evacuation PREVENTION Warnings Information Education Urban planning Legislation and regulation Land use controls Structural works Asset management Temporary accommodation Relief centres Planning Preparedness Training Community awareness Funding Advocacy Insurance Rebuilding Community action Restoration Advocacy RECOVERY Community Support programs Counselling Personal support Material aid (There is more information about the organisations contributing to prevention, response and recovery throughout this document. Appendix 1 shows a summary of flood management roles.) 4 Draft Flood Management Strategy Port Phillip and Westernport

93 SECTION 1 About the Port Phillip and Westernport region Our region is home to over four million people. It is densely covered with homes, businesses, agricultural land, and infrastructure. The region s population is expected to almost double by This means that floods have the potential to affect a great number of people and assets. The Port Phillip and Westernport region, Victoria Our region covers approximately 13,000 square kilometres, extending from high in the Yarra Ranges to the east, to Ballan in the west, to Kinglake in the north, and south to include Mornington Peninsula, and Phillip and French Islands. Approximately 130,000 properties are known to be affected by floods. (More information about the number of properties at risk is available on page 11.) The consequences of floods are serious for people living in affected areas, and can have major economic repercussions for the state. 2 As the region continues to grow, we need to manage the risks to avoid new or increased hazards to people, and minimise property and environmental damage, economic costs, and disruption to communities. Our region is unique in Victoria because of the many different organisations that work together to manage flood risks, including 38 councils, retail and wholesale water authorities, and policy, planning and emergency management agencies. 1. Plan Melbourne 2013, Victoria in Future Victorian Economic and Financial Statement 2011 The region includes five major river basins: the Werribee, Maribyrnong and Yarra Rivers, Dandenong Creek, and the Westernport river systems. Legend: Region Major waterways River basins Established urban area Growth corridors Draft Flood Management Strategy Port Phillip and Westernport 5

94 Building on progress so far This strategy builds on progress delivered under the 2007 Flood Management and Drainage Strategy. Outcomes of the 2007 strategy include: Improved knowledge Improved knowledge of regional flood risks through ongoing flood modelling and mapping, development of a standardised risk assessment framework, and ongoing inclusion of flood information in planning schemes and growth corridor plans. Improved understanding Improved understanding of the potential future pressures on existing drainage systems resulting from predicted climate change and increased development in established urban areas. Local flood management plans and improved collaboration Progress toward agreed approaches to the management of existing regional flooding problems and improved collaboration, through development of local flood management plans for every municipality in the region. Reduction of intolerable flooding Reduction of intolerable flooding by 10% across the region through measures to decrease either likelihood or impact, including a number of major drainage system upgrades, education programs, and warning systems. Local flood and drainage infrastructure upgrades Delivery of a wide range of localised flood and drainage infrastructure upgrades to support local risk reduction and development. Enhanced community education, awareness and preparedness Enhanced community education, flood awareness and preparedness in partnership with VICSES and councils. Expanded network of streamflow gauges and flood warning services An expanded and maintained network of streamflow gauges, and ongoing provision of targeted flood warning services in partnership with BoM and VICSES. Updated flood mapping and ongoing development advice Ongoing updates to planning schemes to include flood mapping, and ongoing development advice to councils and landowners where new developments could be affected by flooding. The experience and working relationships developed through delivering the 2007 strategy have highlighted challenges for the region, and opportunities to keep improving our service. Challenges and opportunities include: Infrastructure upgrades Infrastructure upgrades have been targeted at the highestpriority and best-value locations, and designed to be as cost-effective as possible; however, they are generally very expensive. As we work to address risks in areas where infrastructure upgrades are more difficult, the cost of traditional infrastructure works could outweigh the benefit. We need to consider all available tools to build resilience and deliver good value flood risk management, tailored for each location and community. Catchment scale issues Catchment scale issues including integrated water management, land use and development planning, and drainage management are critical to effective flood management. They can be key drivers of both flood risks and flood solutions. Coordinating activities in all these areas will support good outcomes in the long term. Supporting emergency response and recovery preparation As we cannot remove all flood risks, well-prepared and aware communities and emergency response services are essential; they can help reduce the impact of floods and speed up recovery, improving resilience. Floodplain management activities need to support emergency response and recovery preparation, and help build resilience. To meet emerging challenges and to continue delivering services effectively, the flood managers contributing to development of this strategy have identified ongoing communication, greater collaboration, and more transparent decision making and planning by all stakeholders as key areas for focus. 6 Draft Flood Management Strategy Port Phillip and Westernport

95 SECTION 2 A shared vision for Port Phillip and Westernport VISION Together we are aware, responsive and resilient. Communities, business and government understand flooding, plan for challenges, and take action to manage risks. OBJECTIVE 1 The right information is available at the right time to people who need it OBJECTIVE 2 Flood risks are addressed to reduce impacts and get the best social, economic and environmental outcomes OBJECTIVE 3 Land, water and emergency planning agencies work together to manage flooding Flood data and risk information is produced and shared to meet regional priorities and needs. Flood decision makers have up-to-date information, and the skills and capacity they need to be effective. Communities understand their flood risks and how they can manage them. OUTCOMES Flood risk management programs are delivered for the best value, focusing on highest-priority areas first. Future risks are identified and included in flood management planning. New developments and suburbs are well planned, to avoid increases in flood risk. Risks associated with climate change and urban development are planned for and managed. Ongoing floodplain management activities are supported by clear roles and responsibilities. Land, water and emergency planning activities are well coordinated to help reduce risks. Draft Flood Management Strategy Port Phillip and Westernport 7

96 Targets Targets have been developed to track critical indicators of progress toward the vision and objectives. While each target has a primary relationship with one objective, they work together as a group to track how implementation of the overall strategy is delivering the vision and the three objectives. The objectives and targets track the outcome of work by many organisations. Objective 2021 targets* More information 1. The right information is available at the right time to people who need it 2. Flood risks are addressed to reduce impacts and get the best social, economic and environmental outcomes 1a 65% of catchments and coasts are flood-mapped, and current and future risks are assessed to an agreed standard, starting with priority catchments; information is made publicly available. 1b 100% of available public flood risk information is made accessible to help everyone understand and manage their flood risks. 1c 30% of people directly affected by flooding are aware of their flood risks and know what to do. (Effort is targeted at highest-risk areas first). 2. Agreed flood management approaches are being delivered in 100% of highest-priority areas to address the likelihood or consequences of flooding. Progress in mapping and understanding flood risk, and sharing information, is an essential outcome. This strategy outlines actions to ensure ongoing mapping and risk assessment produces the right information for our region, and that it is shared. We aim to complete all remaining mapping and risk assessments as soon as practical, and continue to update them over time. Flood information will be made as accessible as possible to the general public through improved design and availability, supporting people to find and use the information they need. Research indicates that public awareness of flood risk is low, and many people do not realise they could be at risk. Targeted awareness-raising will be undertaken to improve awareness and preparedness, reducing flood risks and impacts. We will work to increase awareness in highest-risk areas first, and improve awareness everywhere over time. This target tracks our progress in developing and implementing agreed flood management solutions in the areas where they are needed most. Actions in this strategy outline how priorities will be agreed, and how flood management decisions will be made, to make best use of available funds. 3. Land, water and emergency planning agencies work together to manage flooding 3. By 2021, locally and regionally appropriate flood management approaches will be collaboratively developed for 40% of catchments and coasts, taking into account current and future risks. This target measures our progress in planning for the present and future across the entire region. All stakeholders influencing flooding will need to work together to ensure flooding is managed across the region, and take actions required now to ensure risks do not get worse in future. * Baseline data is now being collated. Targets and Melbourne Water s contribution to delivering them will be finalised using this data and feedback on this draft strategy. 8 Draft Flood Management Strategy Port Phillip and Westernport

97 SECTION 2 These targets require input from all flood management stakeholders. Melbourne Water s estimated contribution is outlined below. Melbourne Water will also continue a wide range of related flood management activities including actions outlined in this strategy to continue delivering effective floodplain management services for the region outcomes Melbourne Water contribution to 2021 targets Key terms 100% of catchments and coasts are flood-mapped, and current and future risks are assessed to an agreed standard; information is made publicly available. 100% of available public flood risk information is made accessible to help everyone understand and manage their flood risks. 100% of people directly affected by flooding are aware of their flood risks and know what to do. Agreed flood management approaches are delivered in all catchments and coasts, taking into account local and regional needs, and current and future risks. 1a MW will lead mapping and risk assessments to agreed standards, for prioritised catchments across the region. A whole-of-catchment approach will be taken wherever possible. 1b MW will lead a review and update of all MW-generated flood information and sharing processes. 1c MW will contribute to development and delivery of a regional community planning and education program delivered by VICSES, targeting areas identified as most urgent or at greatest risk. 2. MW will continue to develop and implement flood management approaches in the region s highest priority areas. We will work with all stakeholders to achieve this target. Developing and agreeing on appropriate approaches in each location will require input from all participating stakeholders. 3. MW will support development of flood management solutions across the region, in collaboration with councils, VICSES, and other stakeholders. Delivery of this target will require participation by everyone. Highest-priority areas Highest-priority areas will be developed for the region in collaboration with government stakeholders and communities. (More on this process is outlined in actions on pagse 21 and 28). Flood awareness Flood awareness describes public and community knowledge of local risks and the possible impacts of flooding, and individuals understanding of how they can manage their own risks. Locally and regionally appropriate flood management approaches Appropriate approaches to minimise current or future flood risks in a local area, considering regional needs. Flood management approaches are developed by flood managers working with local communities to determine the most effective and viable methods to reducing flood risks and their impacts. (See the glossary on page 40). Draft Flood Management Strategy Port Phillip and Westernport 9

98 Car stuck in floodwater, Narre Warren. Floodwater is dangerous never drive, walk or ride through it. Image by David Dashwood SECTION 3 Flooding in our region This section outlines the impact of flooding in our region, and the framework we use for managing flood risks. A short history of flooding in Port Phillip and Westernport Aboriginal inhabitants of our region harvested food and other resources from waterways and floodplains. Floodplains retain important cultural significance. Later European settlement and urban development occurred within floodplains due to their fertile soils and access to water. This has placed buildings and people in the path of flooding. We have also increased the volume of floodwater by clearing forests and developing land; water now flows more swiftly off the surface of cleared and paved landscapes, instead of filtering into soils. Drainage systems built as part of early developments were not designed to hold the volumes of water we now know can flow through our landscape. When there is more runoff than underground drains can carry, water overflows onto surrounding land, flooding roads and properties. Urban development standards for flooding were improved in the 1970s, when new suburbs were required to provide space for floodwaters to be stored, and to flow overland. Suburbs built after the 1970s have a much lower risk of flood damage. The history of the Port Phillip and Westernport region has been marked with many serious and damaging floods. In some locations small, frequent flooding causes significant local damage, inconvenience and disruption. 10 Draft Flood Management Strategy Port Phillip and Westernport

99 SECTION 3 The impact of floods Floods are dangerous to people. Drowning and injury are serious risks, and floodwaters can become contaminated with sewage and other pollutants that pose health risks to people. There are currently approximately 130,000 properties that we know are at risk of flooding in our region. 3 Of these, it is estimated that approximately 15,000 properties include buildings that are at risk of flooding over the floor level. 4 There are likely to be more properties at risk in areas where flood mapping is yet to be completed. More will be affected in the future if flood patterns change as a result of predicted climate change. The average annual damage (AAD) costs of flooding in the Port Phillip and Westernport region are extremely high. Insurance industry information indicates that floods are our most expensive natural hazard. 5 (The personal costs and regional economic effects of flooding are not included in this AAD figure because accurate dollar values cannot be easily determined using the data we have available.) The broader, indirect economic costs of floods have an impact on everyone. Floodwaters can cause significant damage when very deep or widespread, or when moving quickly. Flooding deep enough to cover floors can cause extensive damage to buildings and public infrastructure; however, such large events are quite rare. Smaller, more frequent floods do not generally cause as much physical damage, but the cumulative cost of repeated damage, disruption and social impacts (such as stress) can be very high. The personal and social costs of flooding are less visible than safety hazards and physical damage, but are also very significant. Those who have suffered in floods report longterm stress and disruption from the flood itself, and from losing homes, vehicles, valued personal possessions, and serious disruption to daily life. Floods and floodwaters can damage the natural environment, causing erosion, pollution, and ecological losses that may last much longer than damage to buildings and infrastructure. In some areas, floodwaters have environmental benefits; for example, providing natural seasonal changes in streamflow, replenishing water to natural floodplains, and supporting native vegetation. Flooding in Port Phillip and Westernport This diagram shows current Melbourne Water flood mapping for a 1% AEP flood event. It does not include flood mapping undertaken by other authorities. Legend: Floodplain Coastal floodplain Established urban area Growth corridors Melbourne Water region 3. This is the number of properties we know to be at risk from a 1% AEP flood event; that is, a flood with a 1% chance of occurring in any given year. These properties are at risk of floods that arise along waterways and regional drains. This number is drawn from flood mapping completed by Melbourne Water. More properties may be at risk along local drainage lines, and where mapping is yet to be completed. 4. This is a conservative estimate based on information currently held on Melbourne Water databases. The actual number of buildings that could be at risk of above floor flooding during a 1% AEP flood is likely to be higher, and will be determined as more data is collected and analysed. 5. Flood Risk Management in Australia 2008 Draft Flood Management Strategy Port Phillip and Westernport 11

100 Past risk assessment This diagram shows catchments where risk assessments have been made by Melbourne Water. Risk assessments are updated as better information becomes available. Risk assessment outcomes are shown for entire catchments, but the area actually at risk of flooding is much smaller. You can see a diagram of floodplains on page 11. Risk assessments are made using a Flood Risk Assessment Framework that allows the likelihood and consequences of floods to be quantified in a consistent way. The framework considers a range of issues including: the possible size of floods past flooding how hazardous floods could be the number of properties affected potential physical damage local issues such as possible effects on vulnerable communities flood management measures already in place. (More information about the framework and how we plan to update assessments and expand our approach to understanding flood risks is available on page 21). Many flood management projects have been completed to reduce risks across the region; more information about regional flood management projects can be found at: Legend: Urban growth boundary Catchment with extreme flood risk Catchment with high flood risk Catchment with medium flood risk Risk yet to be assessed Flooded foot path, Lower Yarra 12 Draft Flood Management Strategy Port Phillip and Westernport

101 SECTION 3 HISTORY OF FLOODING Below is a timeline showing some of the flooding that has occurred over the last 123 years and the changes in our approach to flood risk management. Port Phillip and Westernport Flooding Timeline The Great Flood 1934 Over 200mm of rain fell in 48 hours over the Yarra Catchment Elizabeth St flooding mm of rain fell in 1 hour 1974 Maribyrnong River 110mm of rain fell over 48 hours 1983 Werribee 60mm of rain fell in 24 hours 1994 Highest tide reading at St Kilda Marina m 1996 Bunyip - 42mm of rain fell in 24 hours 2003 Darebin, Banyule, Whitehorse and Manningham 106.5mm of rain fell in 2.5 hours Severe localised storms across eastern & north eastern suburbs Widespread riverine flooding across the Melbourne region up to 125mm of rain fell in 24 hours 2006 Northcote and Coburg 75.2mm of rain fell in 30 minutes 2014 Melbourne CBD, Elwood, Werribee and Bunyip region up to 150mm of rain fell in 14 hours Koo Wee Rup, 80mm of rain fell over 2 days Second highest tide reading at St Kilda Marina m Draft Flood Management Strategy Port Phillip and Westernport 13

102 What happens when it floods Flooding is a part of the natural environment. We can t stop it, but we can manage the risk. 1 Natural Floodplain Flooding can benefit natural landscapes. 2 Riverine flooding occurs where we ve built in natural floodplains when rainfall exceeds the capacity of a river or creek it overflows onto the surrounding land. 3 Flooding is a risk to safety. It can damage homes, causing stress and personal loss. 4 Flooding can happen in places you might not expect. Overland flooding happens when rainfall exceeds the capacity of our drains and pipes. 5 Flooding costs everyone and not just financially. Even if you aren t flooded, public transport and roads can be blocked, stopping people getting where they need to go. Flooding can cause damage to workplaces, businesses and public infrastructure. These issues have broad economic impacts. 6 Very high tides caused by storms can result in coastal flooding. Climate change could make this worse. The Port Phillip and Westernport region is at risk of flooding and if we don t continue to manage these risks it could get worse. Within our region we know of approximately 130,000 properties at risk of flooding. Flooding is our most expensive natural hazard. 14 Draft Flood Management Strategy Port Phillip and Westernport

103 Flooding on Elizabeth Street, 1972 Flooded house, Elwood A VICSES worker exits a flooded underground carpark, St Kilda Road closures due to flooding, Narre Warren Image by David Dashwood Draft Flood Management Strategy Port Phillip and Westernport 15

104 Managing large and small floods This strategy will help flood managers address all kinds of flooding, from the small and frequent floods to very large, infrequent floods Types of flooding and their effects: COMMON TERMS Minor Moderate Major SIZE Smaller Bigger FREQUENCY Occur often Occur less often RISK Maybe smaller Maybe bigger Drainage system operating Drainage system overflows Overland flooding Riverine flooding WHAT S HAPPENING Stormwater FLOODING is contained in the drainage IMPACTS system and rivers and creeks Coastal and storm surge Stormwater overflows into streets and possibly properties. Inconvenience and disruption, some damage Major overflow and widespread flooding. Damage to property and environment. Major disruption. Social impacts. Social, environmental and economic impacts (See the glossary on page 40 for an explanation of terms in this diagram.) 16 Draft Flood Management Strategy Port Phillip and Westernport

105 SECTION 3 Common terms to describe severity of floods There are a range of terms used to describe the scale or severity of floods. The terms below are used to describe the size of floods, and are often used in flood warning services and other public communication about flooding. Minor flooding Minor flooding causes inconvenience. Low-lying areas next to waterways are inundated. Minor roads may be closed and low-level bridges submerged. In urban areas inundation may affect some backyards and buildings below the floor level, and affect some bicycle and pedestrian paths. In rural areas removal of stock and equipment may be required. Moderate flooding In moderate flooding main traffic routes may be affected. Some buildings may be affected above the floor level. Evacuation of flood affected areas may be required. In rural areas removal of stock is required. Major flooding Extensive rural areas and/or urban areas are inundated. Many buildings may be affected above the floor level. Properties and towns are likely to be isolated and major rail and traffic routes closed. Evacuation of flood-affected areas may be required. Utility services may be impacted. Types of flooding where water comes from Overland flooding Overland flooding occurs when runoff from storms exceeds the capacity of our drains and pipes, and overflows onto surrounding properties. Overland flooding can happen very quickly. Floods that rise very rapidly are often known as flash floods. Riverine flooding Riverine flooding occurs when runoff from storms exceeds the capacity of a river or creek and overflows onto surrounding land. Coastal and storm surge flooding Very high ocean tides occurring during storms can cause flooding along coasts and the lower reaches of rivers, particularly when combined with high rainfall. Local flooding can cause disruption. Floodwater is dangerous - never drive, walk or ride through floodwater. These definitions are taken from the Bureau of Meteorology s Definitions of Terms Used in Flood Warnings (See the glossary on page 40.) When describing the risk of floods, Melbourne Water currently uses the terms Extreme, High and Medium. These labels are applied where flood risk (including both the likelihood and consequence) has been assessed by Melbourne Water. The following sections outline how the current approach to understanding flooding and risk will be updated to better reflect all kinds of flooding. Draft Flood Management Strategy Port Phillip and Westernport 17

106 How flooding is managed Although we cannot fix all flooding, we can work to reduce the likelihood of flooding in some locations, and minimise the impact when a flood does happen by being well prepared and ready to manage the consequences. Flood risks in Port Phillip and Westernport are managed according to national and state best practice guidelines set out in the Revised Draft Victorian Floodplain Management Strategy and Managing the floodplain a guide to best practice in flood risk management in Australia. 6 The table below summarises the floodplain management process in our region. The floodplain management process Understand the risk Objective 1 Mapping and assessing risks LAND & WATER & Sharing information INFRASTRUCTURE with those who need it WATERWAYS Engaging communities to understand risk and build resilience The right information is available at the FLOODPLAIN EMERGENCY right time MANAGEMENT to people who need it MANAGEMENT State Victorian Climate Water supply policy and Victorian Floodplain Victorian Emergency Manage existing Change risksadaption Plan IWM policies and plans Objective Management 2 Strategy Management Framework Victorian Waterway State Flood Management Strategy Emergency Plan Manage known risks making best use of resources Flood risks are addressed to reduce impact Regional Avoid new risks Plan by Melbourne managing development Regional Healthy and get Regional the best Flood social, economic Central and environmental Flood Waterways and outcomes Management Emergency Plan Plan ahead for future risks Stormwater Strategies Strategy Implementation Work Localtogether Precinct to improve Structure our Plans effectiveness Municipal water Objective Municipal 3 Flood Municipal Planning strategies Management Plans Policies (where applicable) Clarify roles where necessary Improve coordination across all flood managers Municipal Emergency Management Plans Land water and emergency planning agencies work together to manage flooding This strategy sits within a framework of related policies and strategies that work together to help prevent and manage flooding, and support response and recovery. LAND & INFRASTRUCTURE WATER & WATERWAYS FLOODPLAIN MANAGEMENT EMERGENCY MANAGEMENT State Regional Victorian Climate Change Adaption Plan Plan Melbourne Water supply policy and IWM policies and plans Victorian Waterway Management Strategy Regional Healthy Waterways and Stormwater Strategies Revised Draft Victorian Floodplain Management Strategy Regional Flood Management Strategy Victorian Emergency Management Framework State Flood Emergency Plan Central Flood Emergency Plan Implementation Local Precinct Structure Plans Municipal Planning Policies Municipal water strategies (where applicable) Municipal Flood Management Plans Municipal Emergency Management Plans 6. Revised Draft Victorian Floodplain Management Strategy, 2015, Managing the Floodplain: a guide to best-practice flood risk management in Australia, Draft Flood Management Strategy Port Phillip and Westernport

107 SECTION 3 Who participates in floodplain management? Many organisations have a role in preparing for and managing flood risks, including activities in prevention, preparation, response and recovery; such as: Melbourne Water (regional drainage and floodplain management authority): > coordinates planning and delivery of flood management services at a regional level > manages waterways > contributes to development and implementation of integrated water management (IWM) knowledge and tools. 38 councils: > manage local urban planning and building local drainage > support local community resilience > contribute to regional flood management > develop and implement local flood plans and IWM infrastructure as appropriate. Retail water authorities: > manage urban water resources > undertake technical research > develop and implement IWM infrastructure and tools with other stakeholders. Victorian State Government departments and agencies: > set policies and state guidelines for floodplain management, urban planning and development, and water resource management > support recovery from floods. Emergency services agencies: > lead emergency preparation and response > deliver community, education, awareness and preparation programs. Federal Government organisations: > set national policies and guidelines for flood and emergency management > coordinate national research and data > provide some funding for flood prevention and recovery activities. Communities, individuals and businesses: > responsible for understanding personal and local risks, and taking appropriate preparation and risk management steps > can contribute to development of local flood management plans and projects. Melbourne Water retarding basin holding flood water, Narre Warren South. Image by David Dashwood Draft Flood Management Strategy Port Phillip and Westernport 19

108 Yarra River in flood SECTION 4 Objectives, targets and actions Understanding the risk and sharing information OBJECTIVE 1 The right information is available at the right time to people who need it This section covers: Mapping and assessing risk Sharing information with those who need it Engaging communities to help them understand their risk and build resilience RELATED TARGETS 1a By 2021, 65% of catchments and coasts are flood-mapped, and current and future risks are assessed to an agreed standard, starting with priority catchments; information is made publicly available. 1b By 2021, 100% of available public flood risk information is made accessible, to help everyone understand and manage their flood risks. 1c By 2021, 30% of people directly affected by flooding are aware of their flood risks and know what to do. 20 Draft Flood Management Strategy Port Phillip and Westernport

109 SECTION 4 Understanding the risk The first step to manage flooding is to understand risk. Risk is the combination of the likelihood and consequence of flooding. 7 We can model and map potential flooding to understand where floodwaters are likely to flow, how fast they might rise and fall, and how often. We can estimate the local impact using information about local communities and infrastructure. We can then calculate risk in a particular location by combining the likelihood of flooding and information about the local consequences of floods. In our region, a Flood Risk Assessment Framework (FRAF) is used to analyse detailed information about the possible size and impact of floods in each catchment in a standardised and systematic way. In this way, we can quantify and compare risk in different locations. This information allows us to prioritise our efforts and consider what kinds of management approach may be appropriate in each location. Next steps Flood mapping Melbourne water undertakes flood modelling and mapping along regional waterways and drainage assets. Modelling has been completed across growth corridor catchments, and some mapping has been undertaken in approximately 64% of established urban catchments and rural catchments. This work has focused on urban and intensively farmed areas where floods are expected to cause most damage. Detailed risk assessments have been completed in catchments where mapping is available, and where higher risks are more likely. Ongoing mapping and risk assessment is needed to fill gaps and upgrade data in line with new standards as they emerge. Possible flooding from storm-tides and future sea level rise has been mapped for the whole Port Phillip and Westernport coastline. 8 (More information about future coastal risks is provided on page 33.) Melbourne Water has a rolling program of mapping in place to fill the gaps in regional flood mapping, and update existing data to provide a more comprehensive picture of current and future risks across each catchment. Flood mapping and risk assessment is yet to be completed for areas with low populations or little urban development, and for many local drainage systems. 1. Prioritising and completing flood mapping and risk assessment studies to address the most urgent information gaps. This includes understanding what level of information is required from rapid-response maps to highly detailed flood mapping. Actions Lead Key participants 1.1 Facilitate and lead development of a new flood mapping prioritisation tool for the whole of our region, in collaboration with stakeholders, including communities. A new tool will address both urgency and levels of detail required, to ensure fit for purpose information is produced. 1.2 Regularly prioritise mapping and risk assessment projects in consultation with stakeholders and local communities. (Prioritisation will be undertaken on a whole of catchment basis where possible). MW MW Councils, VICSES, DELWP, MAV, MPA Councils, VICSES 1.3 Continue delivering priority mapping and risk assessment projects in consultation with stakeholders (on a whole of catchment basis where possible). 1.4 Continue contributing local and technical expertise, requirements and knowledge to regional prioritisation, and to mapping and risk assessment projects. 1.5 Undertake additional local flood mapping and assessment if required due to local priorities, in consultation with stakeholders and local communities. MW Councils, MPA Councils Councils, VICSES MW, VICSES 7. Managing the Floodplain: a guide to best-practice flood risk management in Australia, The Victorian Coastal Inundation Data Set produced through the government s Future Coasts program models and maps current and possible future coastal flooding. Melbourne Water has completed additional coastal flood mapping for Port Phillip and Westernport. Draft Flood Management Strategy Port Phillip and Westernport 21

110 2. Agreed mapping and risk assessment standards and processes tailored to our region are needed to ensure we produce the right information as efficiently as possible. Actions Lead Key participants 2.1 Lead review and update of modelling, mapping and risk standards and processes for our region, in alignment with state and national standards and in collaboration with stakeholders. 2.2 Participate in review and update of regional flood study standards and processes to help ensure new approaches can be applied in local as well as regional scales. MW Councils DELWP, Councils, VICSES, BoM, other regional and technical authorities as required. 2.3 Continue sharing mapping and risk assessment outcomes with stakeholders. MW, Councils 3. Better data on existing drainage and flood assets and changing landscapes is needed to inform ongoing asset management, and to underpin all flood mapping and management projects. (Good records of infrastructure were not kept during the early development of our region.) Actions Lead Key participants 3.1 Continue and enhance collection and sharing of data of flood and drainage assets and land, to inform flood studies and asset management programs, and respond to new information requirements as they arise. Melbourne Water, Councils, Retail Water authorities (For assets under each agencies control) DELWP Outcome: Flood data and risk information is produced and shared to meet regional priorities and needs. Cleaning up after flooding at the Angler s Tavern, Maribyrnong 22 Draft Flood Management Strategy Port Phillip and Westernport

111 SECTION 4 Sharing information It takes the actions of many stakeholders to manage flood risks, and everyone needs to use good information. Detailed flood information is required for managing existing risks, and for good urban planning, emergency planning, community education, and adaptation. These activities are undertaken by many organisations. Critical infrastructure and service providers need information on flooding to enable them to design and provide resilient services. State government departments, councils, and emergency services all share flood mapping and risk information to support flood risk reduction and to plan for flood emergencies. Information is currently shared through many channels including: Annual flood updates for councils from Melbourne Water Collaborative development of Local Flood Management and Flood Emergency Plans Ongoing knowledge sharing and capacity building programs run by government and research organisations Flood information included in municipal planning schemes and policies MW provision of flood mapping information to the Victorian Flood Database Ongoing flood information updates from Melbourne Water to VICSES Flood warning systems Emergency planning processes Project-based information sharing between Melbourne Water, councils, BoM, and VICSES Development advice to landowners Statutory public information processes such as planning schemes, property information statements and flood level advice Provision of flood mapping to the insurance industry through the Insurance Council of Australia (ICA). Continued information sharing is essential, and there are opportunities to improve current processes. Community education and awareness programs are a critical aspect of information sharing. (The ongoing delivery and improvement of community awareness programs is addressed in more detail in the following section.) Next steps 4. Building knowledge and skills will help all stakeholders keep up with a changing environment, new research, and new flood management approaches and technology. This is necessary to continue delivering good value and effective services. Actions Lead Key participants 4.1 Identify and prioritise regional floodplain management knowledge and capacity gaps. 4.2 Lead and facilitate targeted research and stakeholder capacity building programs to address priority gaps. 4.3 Identify local or subject matter knowledge and capacity gaps, and coordinate with other authorities to help address them. MW MW VICSES, Councils DELWP, VICSES, Councils, MAV, technical and research authorities DELWP, VICSES, Councils, MAV MW, DELWP 5. Learning from floods when they do occur allows flood models and maps to be checked against real data, and supports ongoing improvement of emergency response and management processes. Ongoing information gathering from all participating authorities is required. Actions Lead Key participants 5.1 Review what data is being collected by different organisations during and after floods, and identify further opportunities to collect and share data. 5.2 Facilitate data and information sharing following floods, and use new information to review and update flood models and emergency planning. MW MW VICSES, Councils, MAV Councils, BoM Draft Flood Management Strategy Port Phillip and Westernport 23

112 6. Ongoing improvement of information sharing programs and technology is needed to ensure that up-to-date information is accessible and can be used by those who need it. This supports good flood management decision making by all stakeholders who influence floodplains. It enables insurance companies to understand true risks, helping them avoid defensive policy pricing. Actions Lead Key participants 6.1 Review current information storage and sharing processes, and identify where the type, format, and timeframe of information sharing could be improved. MW DELWP VICSES, Councils, MAV, Retail Water Authorities, 6.2 Regularly share updated regional flood data with relevant authorities and the insurance industry (through the ICA), to support strategic urban development, emergency planning, and appropriate insurance pricing. MW ICA Outcome: Flood decision makers have up-to-date information, and the skills and capacity they need to be effective. Building community resilience Communities and businesses have an important role in managing their own risks, reducing the local impacts and costs of flooding. Flood ready communities and individuals understand their risks, are prepared for flooding, and respond to warnings. They can make informed investment and insurance decisions to reduce their risk exposure. Flood ready communities that have taken steps to prepare for and manage risks are likely to experience less loss, damage, stress and disruption, and recover faster. Community flood awareness is currently supported through local flood guides and education programs. These are delivered by VICSES (Victoria State Emergency Service) in partnership with Melbourne Water, and by some councils. General flood information is also available in planning schemes, and through property information statements and flood level advice provided on request by Melbourne Water. Flood warnings are in place for flood risk areas along most major river systems. Pilot warning systems are in place in two locations at risk of severe flash flooding. Further early warning systems for urban flooding are currently in development using Bureau of Meteorology and Melbourne Water data. Resilience better enables cities, organizations, and communities better prepare for, respond to, and transform from disruption. 9 Flood awareness and readiness is an important aspect of resilience. 9. Rockefeller Foundation Draft Flood Management Strategy Port Phillip and Westernport

113 SECTION 4 Next steps 7. Ongoing community engagement and education programs are needed to help people understand what to do before and during a flood, and the benefits of being prepared. Effective engagement requires accessible, locally relevant information. 10 Sustainable resourcing for ongoing delivery, and regular evaluation and updates are required to ensure programs are effective. Actions Lead Key participants 7.1 Identify the highest priority locations and communities for flood risk awareness and engagement programs, with input from relevant authorities. VICSES MW, Councils, DHHS 7.2 Regularly evaluate and update regionally-funded education and awareness programs. MW, VICSES EMV, Councils 7.3 Continue to deliver targeted education and awareness raising programs and materials, with support and input from delivery partners. 7.4 Lead targeted education and support for vulnerable communities community service organisations, where necessary to deliver statutory or policy responsibilities, and address local priorities. VICSES DHHS MW, Councils Councils 7.5 Contribute local knowledge to regional education and awareness planning. Councils 8. Flood warnings can help communities to respond to floods effectively. Effective warning services for urban areas prone to flash flooding are a particular challenge for our region. This is because flash floods happen quickly, and are hard to predict in advance. Any warnings must be extremely accurate and rapid to give people time to respond. Actions Lead Key participants 8.1 Review regional flood warning services and processes to ensure: Alignment with relevant state and national standards and guidelines (eg Victorian Total Flood Warning Service guidelines) That they provide a fit-for-purpose service proportionate with regional risks, including flash flooding. 8.2 Continue to operate stream and rainfall gauging networks to support flood prediction and warning services. MW, BoM, VICSES MW EMV, DELWP, Councils 10. Findings from VICSES and Melbourne Water Education Program Evaluation Survey research, 2012 Draft Flood Management Strategy Port Phillip and Westernport 25

114 9. Build awareness through improved public flood information sharing. Making clear flood risk information accessible to people and businesses enables and encourages them to review their personal flood and property planning, and make appropriate flood insurance decisions. Actions Lead Key participants 9.1 Review statutory and routine information sharing processes such as local flood guides, Property Information Statements and Flood Level Advice for accessibility, and where necessary revise them in consultation with stakeholders. MW, VICSES DELWP, Councils Communities also need to be engaged in development and decisions about local flood management programs. (This is addressed in the next section.) Outcome: Communities understand their flood risks and how they can manage them. Flooding at Dights Falls on the Yarra 26 Draft Flood Management Strategy Port Phillip and Westernport

115 SECTION 4 Taking action to manage current and future risks OBJECTIVE 2 Flood risks are addressed to reduce impact and get the best social, economic and environmental outcomes This section covers: Manage known risks making best use of resources we have Avoid new risks Plan ahead for future risk. RELATED TARGETS 2. By 2021, agreed flood management approaches are being delivered in 100% of highest-priority areas to address the likelihood or consequences of flooding. Managing existing flood risks Flood management activities can range from major infrastructure works to protection of natural floodplains, urban planning, water harvesting, community education, emergency response and recovery, and insurance. These activities can have widely varying costs and benefits, and acceptability in different community settings. In taking action, flood managers must consider the overall cost and effectiveness, the number of people and properties that benefit, and the positive outcomes (for example environmental protection, recreation and green space, and local amenity) that could be provided. Available funding cannot remove all flood risks immediately, and some flooding is unlikely to ever be possible to remove. Starting with the highest-priority locations, we will investigate what can be done to reduce physical flood hazards, and reduce or manage consequences. Communities are an essential contributor to the development of local flood management options. They provide local knowledge and priorities, and contribute to decision making on how local flood infrastructure should be designed to complement local urban settings and community uses. Melbourne Water has worked with a range of stakeholder agencies to develop a risk assessment framework to prioritise catchments for flood management activity. This has informed our program of work over the last five years. Many councils have also undertaken works to reduce local risks, and provide education and emergency response programs to help speed recovery. Even where flooding can be reduced through physical works, a lower risk may continue to exist, and in some areas it is not feasible to reduce the likelihood of physical flooding. A range of other tools must also be used to reduce the consequences of floods. Other measures to reduce risks include: Flood emergency response planning across the region, undertaken by VICSES using input from government and communities Community education and awareness programs, enabling local preparation and risk management such as insurance Stream and rainfall monitoring networks and flood warning systems. Draft Flood Management Strategy Port Phillip and Westernport 27

116 Choosing the right approach Though we can t prevent all flooding we can manage some of the risks. Managing flood risks can reduce costs to individuals and the community. Be prepared Emergency organisations and communities prepare for floods e.g warnings and insurance. Benefits Low cost activities can reduce personal risk Issues Requires people to be aware and take responsibilty for their flood risk. Plan and build wisely Don t build in the path of flooding and build safely. Benefits Very low cost Very effective Green space for community recreation Stops redevelopment making things worse. Collect and store rainwater where it falls For example using rain tanks. Benefits Can provide benefits beyond flood protection e.g water supply Issues Only works in some places Needs careful management Upgraded infrastructure For example building retarding basins, channels and bigger pipes to contain flood water. Benefits Where feasible it can be very effective at reducing risk Issues Very expensive Can be very disruptive There are many different tools to manage flood risks, but not all measures are equal. We need to weigh up the costs and benefits of each measure when deciding what to do. Benefits Costs Next steps 10. To identify the highest priority areas for action over the next five years, we will review and update our current prioritisation framework to better account for the wide range of current and future flood risks we face. Risk assessment and planning will be updated through a rolling program to ensure we are planning for long-term and short-term requirements. Actions Lead Key participants 10.1 Review and update the framework for identifying highest priority areas for flood management action (including current and future risks), in collaboration with stakeholders and communities, to enable transparent prioritisation at regional and local scales Regularly prioritise regional flood risk areas in collaboration with partner organisations, and communicate priorities to all stakeholders including communities Contribute local knowledge and priorities to development of a regional flood prioritisation framework, and development of priority lists Prioritise and plan for local risks as required, and share related information with MW and VICSES. MW MW Councils Councils Councils, VICSES, DELWP, MAV, EMV, EPAA Councils, VICSES MW, VICSES 28 Draft Flood Management Strategy Port Phillip and Westernport

117 11. To develop the right mix of responses for each priority risk area, flood studies must consider the full range of flood management options, local catchment and environmental conditions, community priorities, and the costs and additional benefits (such as water supply or amenity) in each location. To deliver agreed flood management solutions for each location, regional authorities need to work together to develop business cases, funding sources, and delivery plans. Actions Lead Key participants 11.1 Continue to work with local authorities and communities to develop and implement flood management options for regional priority flooding Continue to work with community and government stakeholders when addressing local priority flood risks, to develop and implement locally and regionally appropriate options Review and update local Flood Management Plans and Flood Emergency Plans to include new information, priorities, and agreed flood management solutions Contribute specialist and technical information to regional and local flood management planning as required. MW Councils Councils, MW Retail Water Authorities, BoM Councils, VICSES, BoM, DELWP, Retail Water Authorities MW, VICSES, Retail Water Authorities VICSES 12. Engaging local communities in flood management projects is essential to ensure flood management solutions are locally appropriate, and support communities to understand their local risk. Actions Lead Key participants 12.1 Engage residents, business and relevant government agencies in development of flood management options and decision making. MW, Councils VICSES, Retail Water Authorities, MPA 13. Ongoing management of flood and drainage infrastructure is necessary to ensure systems remain safe, and continue to function to agreed operating standards. Maintenance and upgrade activities need to consider flood and drainage functions together, to get the best performance from our assets. All asset managers need to work together and share information to ensure planning and management is undertaken on a whole-of-catchment basis. Actions Lead Key participants 13.1 Melbourne Water will continue planning for and managing flood and drainage assets servicing regional catchments*, and sharing this information with relevant stakeholders Councils will continue planning for and managing flood and drainage assets servicing local catchments*, and sharing this information with relevant stakeholders. MW Councils Councils, VICSES, Retail Water Authorities, MPA MW, VICSES, Retail Water Authorities *More information on local and regional catchments is included in the glossary on page 40. Outcome: Flood risk management programs are delivered for the best value, and focus on highest priority areas first. Future risks are identified and included in flood management planning. Draft Flood Management Strategy Port Phillip and Westernport 29

118 Avoiding new risks by managing urban development Avoiding new risks associated with urban development is critical. The population of Port Phillip and Westernport is expected to grow by 3.5 million by 2050, adding 1.6 million new households. 11 Unless managed well, this urban growth could increase flood risks. Avoiding new risks in mapped floodplains Because we have good knowledge of where flooding is likely to occur, we can ensure new development is designed and located to avoid placing new buildings and infrastructure at risk. State planning policies and regulations require planning authorities to consider the 1% annual exceedance probability flood when assessing new development in floodplains. Development of established lots Development of established lots within floodplains and flow paths is currently managed by putting planning controls in municipal planning schemes (e.g. Special Building or Land Subject to Inundation Overlays) to identify flood-prone land. Overlays enable Melbourne Water and councils to assess new developments so that buildings will have a lower risk of flood damage, their occupants will be safer, and increases in nearby flood levels are avoided. Planning controls work together with building regulations to ensure new development responds to identified flood risk. When flood mapping is added to planning schemes, communities are notified to ensure they can participate in the planning scheme amendment process and provide additional local knowledge to mapping as required. Information for developers on how to meet the safety requirements for building in floodplains is available in Melbourne Water s guidelines for development in flood-prone areas. New greenfield subdivisions New greenfield subdivisions are required to locate development outside floodplains 12, ensuring new properties are safe, and preserve the storage and safe passage of floodwaters through landscapes. They are required to avoid increasing flood levels downstream. This is achieved through the appropriate location and design of lots and roads commensurate with flood risks, protection of natural waterways, planning for appropriate land uses within floodplains, and design of flood infrastructure including channels and retarding basins. Urban runoff management objectives for new residential subdivisions are prescribed in standard C25 of Clause of all planning schemes. In Port Phillip and Westernport, flood and drainage planning for new greenfield developments is generally integrated with water quality and waterway protection planning during the Precinct Structure Plan (PSP) process for growth corridors. Works and infrastructure are generally delivered by developers through Melbourne Water Development Services Schemes. Detailed flood management requirements for new greenfield development are set out in Melbourne Water s Land Development Manual. Annual exceedance possibility (AEP) This is the likelihood of a flood of a given size happening in any one year. AEP is usually expressed as a percentage; for example if a flood of a particular size (volume of water) has an AEP of 5%, that means there is a 5% (or 1 in 20) chance of a flood of that size happening in any given year. Greenfield development Development of new residential and commercial areas on undeveloped land located on the metropolitan fringe. In our region much greenfield development occurs in designated growth corridors. Infill development Development of higher-density buildings within existing urban areas. This includes building a second dwelling on a residential backyard, or replacing one building on a lot with more or larger buildings. Infill development happens in residential and commercial areas. This is sometimes called urban consolidation. Infill development also includes major re-developments such as conversion of old industrial sites to residential land. These are sometimes known as brownfield developments. 11. Plan Melbourne 2013, Victoria in Future For planning purposes, the floodplain is defined as the area that would be inundated in a 1% AEP flood. Flood plains can sometimes be modified to reduce their size, provided flood carrying and storage capacity is retained. 30 Draft Flood Management Strategy Port Phillip and Westernport

119 SECTION 4 Next steps 14. Ongoing management of planning schemes and development is needed as new information and standards are developed. Melbourne Water works with councils to ensure any new flood mapping is included in local planning schemes. Where necessary councils can also add local policies to their planning schemes to help manage flood risks. Actions Lead Key participants 14.1 Ensure current flood maps are provided to councils and Planning Authorities as available, and support inclusion in municipal Planning Schemes as quickly as possible Maintain and continually improve regional planning and development guidelines and requirements for flooding. MW, Councils MW Councils, DELWP Councils, MPA, DELWP, VICSES, Retail Water Authorities 14.3 Maintain local planning policies in line with relevant flood plans and information. Councils MW 14.4 Incorporate flood information into PSPs. MPA MW, Councils 14.5 Continue to provide planning and development advice on request and as a statutory Referral Authority. MW 14.6 Ensure changes in Planning or Building systems are aligned. DELWP Outcome: New development and suburbs are well planned, to avoid increases in flood risk. Planning for future growth As the region grows, redevelopment and infill development is occurring across established urban areas. The increase in hard surfaces (roofs and paving) associated new development increases the volume of stormwater runoff across a catchment. Increased runoff can increase downstream flood risk, unless it is well managed. Next steps 15. To improve our understanding of the long term effects of urban infill development, we need to understand where new infill development is likely to occur and the cumulative effects in different catchments. Modelling and research of these issues is underway, and ongoing work is required, including input from planning, floodplain and drainage authorities. Actions Lead Key participants 15.1 Continue research to understand the possible flood effects of urban growth and consolidation, in different kinds of catchments across the region. MW, DELWP Councils, MPA, technical and research authorities as required 15.2 Contribute local development information to regional research and planning. Councils, MPA Draft Flood Management Strategy Port Phillip and Westernport 31

120 Integrated water management Integrated water management (IWM) is a way of considering the natural water cycle and all our water supply and management systems, together. It provides new opportunities to reduce flood risks. The aim of integrated water management is to contribute to a more sustainable, prosperous, liveable and healthy community. By planning and delivering flooding, drainage, waterway, water supply and sewage services together, there are opportunities to reduce costs, improve amenity and environmental outcomes, and help make our water supplies as secure as possible. Harvesting or simply slowing down the flow of water that runs quickly off hard surfaces can help to reduce flooding in some areas. Harvested water can be used to keep public spaces and gardens green. Using stormwater and floodwater increases our total water supply, and helps reduce the damage that storm and floodwaters can do to waterways and the bays. Land used to hold and slow flood waters can provide extra benefits by providing space for native plants and animals, and increasing the green open space available for recreation. Community participation in development of IWM tools is essential. It is required to understand the value of local benefits delivered, and to understand when it is appropriate for local residents to participate in delivering infrastructure that can help manage floods (such as rainwater tanks on properties). 16. New tools to manage catchment-scale development are needed to avoid flood risk increasing over time. Some existing tools, such as flood and drainage system upgrades, are extremely expensive. New tools for flood management, such as onsite or local water harvesting, are now being developed using integrated water management approaches. (See above). Ongoing research and collaboration is needed to better understand the effectiveness, costs and benefits of new flood management tools. Actions Lead Key participants 16.1 Continue researching costs and benefits of IWM tools for flood management Provide local and specialist knowledge to research programs and implementation planning for new flood management tools and approaches. DELWP, MW, Retail Water Authorities Councils, Retail Water Authorities Councils, MAV, MPA, technical and research authorities as required, EPA 17. Effective implementation of new flood management tools, particularly IWM approaches, will require sustainable funding, and may require updates to planning and building systems. State government, urban planning, water authorities and floodplain managers need to work together to resolve these issues. Actions Lead Key participants 17.1 Review approaches for planning, delivery and sustainable funding of flood management activities, including new principles for funding infrastructure incorporating IWM services Review the application of IWM flood management tools through existing planning systems, and identify whether adjustments or improvements are required to enable implementation Contribute local knowledge and experience to reviews of how planning systems can be better used to manage growth. DELWP, MW, Retail Water Authorities DELWP, MW Councils Councils, MAV, MPA, DHHS Councils, MAV, MPA, Retail Water Authorities 32 Draft Flood Management Strategy Port Phillip and Westernport

121 SECTION 4 Planning for climate change Climate change is expected to produce more frequent, heavy rainstorms in the south east of Australia. 13 This will likely to lead to bigger floods, more often. Sea levels are also expected to rise, increasing the risks of flooding from sea water in coastal areas. Flood managers have identified climate change as one of the most important challenges we face. Planning and adapting early is likely to cost us less, and be more effective. 14 Flood models and mapping currently produced by Melbourne Water include future scenarios accounting for the effects of climate change, using the current predictions of changes to local rainfall. Very high tides and storm surges can create coastal flooding now, and sea level rise is expected to increase this risk. The effects of sea level rise are being considered in state planning policy. The Victoria State Planning Policy Framework requires decision makers to plan for a rise of not less than 0.8 meters by Preliminary mapping of flooding along coasts in Port Phillip and Westernport Bays has been produced by Melbourne Water, and by the Victorian State Government. Local coastal hazard assessment has been completed for Westernport Bay, and planning for regional adaptation pathways for Port Phillip Bay is now underway. Melbourne Water has produced guidelines for assessing development in areas that are at risk of tidal inundation to support planning authorities in applying state policy and assessing development proposals. Next steps 18. Accurately forecasting the flood effects of climate change relies on using the best available data and standards. National guidelines on how to include climate change scenarios in flood modelling are in development. Updated standards will contribute to developing a regional understanding of the interaction of catchment and coastal floods and how this might affect risk. Actions Lead Key participants 18.1 Update catchment and coastal flood models in consultation with stakeholders to reflect new data, standards and forecasts as they become available, and share new information for coastal hazard assessment and climate change adaptation planning. MW BoM, ABM, Councils DELWP 18.2 Maintain relevant guidelines on development in areas at risk of tidal inundation, and provide advice to planning decision makers regarding land use and development proposals. MW Councils, DELWP 19. Contributing to regional hazard assessments and adaptation planning requires flood managers to work closely with the authorities leading this work. Adaptation plans help to increase certainty and support communities to respond to and manage the local effects of climate change. Ongoing mapping and research will be designed to support coastal hazard assessments and adaptation planning for the region. Actions Lead Key participants 19.1 Develop regional coastal risk assessments in collaboration with partner organisations. DELWP Melbourne Water, Councils ABM, VICSES Outcome: Risks associated with climate change and urban development are planned for and managed. 13. Victorian Climate Initiative Victorian Climate Change Adaptation Plan, Victorian Government Victoria State Planning Policy Framework & Victoria Coastal Council 2014 Draft Flood Management Strategy Port Phillip and Westernport 33

122 Working together to improve our effectiveness OBJECTIVE 3 Land, water and emergency planning agencies work together to manage flooding This section covers: Clearer roles and accountabilities Coordinated activity across catchments, and by all floodplain and emergency managers. RELATED TARGETS 3. By 2021, locally and regionally appropriate flood management approaches will be collaboratively developed for 40% of catchments and coasts taking into account current and future risks. Flood management in Port Philip and Westernport is undertaken and influenced by a large number of organisations. Flood managers in our region see improved cooperation and collaboration across all organisations and disciplines as one of the best ways to improve effectiveness. Australian 16 and Victorian 17 disaster and emergency management strategies confirm the importance of improving collaboration and cooperation to better plan for and manage risks. Establishing better coordination is a significant challenge; people working in prevention, urban planning, water supply planning, emergency response and recovery aspects of flood management must all work together, while supporting business and community participation. Next steps 20. Clarifying roles and responsibilities. There are some areas where stakeholders are not in agreement about roles and accountabilities, or where emerging issues will require roles and accountabilities to be reviewed. These include: aspects of state and local governments roles in planning and preparing for floods, implementation arrangements for some kinds of flood-management infrastructure, aspects of decision making for future risks, and how 60ha planning and management thresholds should be applied. Floodplain managers need to work with state government departments and each other to make sure roles are clear, and address funding and capacity requirements. Actions Lead Key participants 20.1 Clarify roles and responsibilities where the lack of clarity or lack of agreement on statutory and policy roles currently impedes floodplain management action Identify where lack of role clarity creates impediments to carrying out local and community asset planning and management. DELWP Councils MW, Councils, VICSES, BoM Outcome: Ongoing floodplain management activities are supported by clearer roles and responsibilities. 16. National Disaster Resilience Strategy 17. Victorian Emergency Management Strategy (interim) 34 Draft Flood Management Strategy Port Phillip and Westernport

123 SECTION Improved coordination across catchments including land, urban development and waterway planning will support more effective and efficient flood management. There are opportunities to improve how floodplain managers work with decision makers in related areas to ensure complementary outcomes from all our work. Actions Lead Key participants 21.1 Identify where more information sharing or collaborative planning can support coordinated activities across land, waterway, and water supply planning Continue sharing flood information with waterway, coastal and water supply managers, and consulting on specific projects Continue consulting with all relevant coastal, waterway and water supply managers on regional and local flood management projects. DELWP MW Councils, MW Councils, Water Authorities, MPA PPWCMA, MAV, DELWP 22. Floodplain managers support emergency response and recovery agencies to reduce risk and impact during and after floods. This includes producing information on risks and contributing to warning services. We can further support communities by ensuring floodplain management decisions consider emergency response needs, and long term resilience. Actions Lead Key participants 22.1 Work with stakeholders to identify opportunities to improve communication and collaboration Include new flood mapping and other relevant information in emergency response planning as it becomes available Continue making flood information available to essential service providers to enable them to consider and plan for flood risks and minimise service disruption Continue consulting with emergency services agencies when undertaking flood mapping and management projects Continue undertaking joint emergency response training exercises, with input from relevant stakeholders Continue leading regional and local emergency response and recovery planning, with input from relevant stakeholders (including communities). MW, VICSES, EMV VICSES, Councils MW, VICSES MW, Councils VICSES VICSES Councils, MAV, BoM MW, EMV EMV, Councils VICSES MW, Councils, EMV EMV, Councils, MW Outcome: Land, water and emergency planning activities are well coordinated to help reduce risks. Draft Flood Management Strategy Port Phillip and Westernport 35

124 Little River in flood SECTION 5 Delivering this strategy The vision, objectives, actions and outcomes outlined in this strategy have been developed in close consultation with floodplain management stakeholders. They reflect the work and responsibilities of many government authorities, and delivering them will require participation by everyone. This section provides an overview of the strategy governance processes. These processes will be developed further with input from participating stakeholders for inclusion in the final strategy. Governance processes will be coordinated by Melbourne Water with the input and participation of endorsing organisations. Review process The strategy will be reviewed every five years. Melbourne Water will also work with stakeholders to establish a dynamic framework for the ongoing update of the contents of the strategy to ensure it maintains relevance during the five-year period. 36 Draft Flood Management Strategy Port Phillip and Westernport

125 SECTION 5 Endorsement and participation Melbourne Water will be seeking endorsement of the final strategy by relevant organisations. Endorsees will agree to: Work together to deliver the vision, objectives and outcomes outlined in the final strategy Participate in strategy governance and reporting processes Advocate both within their organisation and externally for delivery of the vision, objectives and outcomes outlined in the final strategy. The endorsement process, which will take place in late 2015, will provide an opportunity to discuss: How each contributing organisation will participate (for example, through the review and update of local Flood Management Plans to include new strategy direction or participation/delivery of specific projects) Form and timing of progress updates or reports (for example, through existing corporate reporting processes). Oversight An implementation committee will be established with senior representation from each of the endorsing organisations. This committee will meet twice a year and provide oversight of the implementation of the strategy. Implementation A governance resource document, including a framework, will be developed to support endorsing organisations in the delivery of this strategy. The resource document and framework will set out: Detail of the strategy governance processes, including how Melbourne Water will: > Keep a record of endorsing organisations > Coordinate monitoring and reporting processes > Provide oversight of the implementation committee. Detail the monitoring and reporting processes, including: > How individual activity updates will be collated, and regional progress to deliver actions and work towards targets and outcomes will be monitored > Measurement metrics for strategy targets > How targets will be measured. Additional information on actions and outcomes, and how they have been identified and prioritised. Flooding over the road, Lilydale Monitoring and reporting Endorsees will participate in a monitoring and reporting process established by Melbourne Water. This process will be developed in consultation with key stakeholder organisations and be included in the final strategy. Melbourne Water will coordinate the monitoring and reporting process, with input from endorsees. The process will be designed to align with existing reporting processes and be as efficient as possible. Draft Flood Management Strategy Port Phillip and Westernport 37

126 Yarra River in flood APPENDIX 1 Flood management roles Federal Government Includes: BoM, CSIRO, Attorney-Generals Department Emergency Management Set national best practice standards and frameworks for floodplain and emergency management Support development of state strategies and build capacity Undertake weather forecasting and establish flood warning services Carry out technical research and generate data Contribute funding to flood resilience and recovery Regulate insurance industries. Victorian State Government Includes DELWP, DHHS, MPA Set state policies and strategy for managing floodplains and natural resources Set state policies and strategy for emergency response and recovery Lead regional flood relief and recovery Set state policy and standards for urban planning and building Develop local standards and tools for flood management (such as warning systems and messages, risk assessments, and adaptation frameworks). 38 Draft Flood Management Strategy Port Phillip and Westernport

127 APPENDIX 1 Floodplain management authorities Melbourne Water or regional Catchment Management Authority Prepare and implement regional floodplain strategies in line with national and state strategies Develop flood data and information Undertake flood risk assessments and risk-reduction studies Prioritise and implement regional risk-reduction projects in consultation with relevant stakeholders Support emergency response planning and provision of warning services in line with national and state standards and frameworks Advise and support planning authorities on planning for flood-prone land Manage urban development through statutory referral functions Support coastal adaptation planning by councils Contribute to flood clean-up and repair Own and maintain regional drainage infrastructure (in the Port Phillip and Westernport region this generally refers to drainage systems servicing a catchment of greater than 60ha) Manage drainage function and environmental health of waterways and floodplains Help to conserve and protect cultural heritage values of waterways and floodplains. Regional water authorities Manage flood risks to water supply infrastructure Participate in integrated water management research, projects and planning. Emergency services agencies Includes Police, VICSES, EMV Lead flood emergency planning Coordinate responses to flood emergencies Appoint and support local and regional emergency controllers Build and support community awareness and preparedness (with others) Participate in providing warning services (constructing messages and publishing warnings). Councils Administer local planning schemes and building regulations, applying and enforcing standards for land use and development on flood-prone land Develop local policies and for managing the newdevelopment related flood risks Support the conservation of natural and cultural values of floodplains through land use planning and land management Contribute to local community risk assessments Contribute to developing local flood management, emergency management plans Contribute to local flood mapping and risk reduction studies, and project prioritisation Support public awareness and access to flood risk and preparation information Support delivery of warning messages (where warning systems are in place) Provide and manage local drainage infrastructure (in our region this generally refers to infrastructure serving an area of less than 60ha) Help coordinate local relief, recovery and clean-up activities Lead local adaptation for climate change and sea level rise. Communities Contribute local knowledge to flood studies, risk assessment and risk-reduction projects Participate in reducing personal risks by understanding local risk, emergency preparation, and considering insurance Assist with local recovery from flood events. Insurance industry Contribute to setting industry standards on flood insurance Use current information to set premium prices. Draft Flood Management Strategy Port Phillip and Westernport 39

128 Glossary Adaptation Adjustment in response to actual and expected climate change and or effects, to reduce harm or take advantage of opportunities. Annual average damage (AAD) Represents the average yearly cost of flooding in a particular area. It is calculated by taking the total damage caused by all flooding over a period of time and dividing it by the number of years in that period. Annual exceedance probability (AEP) This is the likelihood of a flood of a given size happening in any one year. AEP is usually expressed as a percentage; for example if a flood of a particular size (volume of water) has an AEP of 5%, that means there is a 5% (or 1 in 20) chance of a flood of that size happening in any given year. Avoid Stopping or preventing a flood risk occurring or getting worse. Catchment A catchment is the area of land that drains through a particular waterway or site into a major waterway or regional pipe. The Port Phillip and Westernport Region includes two major catchments, the areas draining to Port Phillip and Westernport. These major catchments can be broken into many smaller catchments draining to particular waterways or pipes. Decision makers The people, organisations and agencies responsible for setting the priorities for flood management in the Port Phillip and Westernport region. Direct damage The direct physical damage caused by flooding. This includes damage to property, buildings, possessions, agricultural land and infrastructure. Flood Flooding is a natural phenomenon that occurs when water covers land that is normally dry. Flood-aware people People who understand their flood risks, and know what actions they can take to minimise them, such as building appropriately, taking out insurance and being emergency ready. Flood management options The range of methods and tools that can be used to reduce or manage the likelihood or consequences of floods. These include: > Urban planning and development to avoid placing buildings or people at risk of floodwaters, avoid increasing or changing the flow of floodwaters, and locate appropriate land uses within known floodplains > Flood emergency preparation and planning by individuals and emergency services organisations > Private risk-management such as insurance > Building and managing physical infrastructure to reduce or control floodwaters such as water storage and drainage infrastructure. Flood risk A combination of the likelihood of a flood occurring and the consequence of the flood when It does occur. Melbourne Water has developed a Flood Risk Assessment Framework (FRAF) that enables us to assess and compare risks at a whole-of-catchment scale. The FRAF rates risks as Extreme, High, or Medium. The current FRAF does not quantify risk at a local or property scale. Greenfield The development of new residential and employment precincts on undeveloped land located on the metropolitan fringe. Highest-priority areas Locations where floods have the potential to have a significant social, environmental or economic impact on the local community. This includes: Catchments with an Extreme Risk (includes assessment of critical infrastructure, number of properties and buildings affected, and vulnerable communities) And/or buildings flooded above floor &/or individual damage threshold And/or a community-informed understanding of what is highest priority (including willingness to pay). This definition will be supported by detailed assessment criteria that will be developed by flood management organisations helping to deliver this strategy. Hot-spot flooding An area that has a history of repeat flooding that causes disruption or damage to properties, buildings, roads or crossings. These areas are typically identified through advice from council and customer complaints. 40 Draft Flood Management Strategy Port Phillip and Westernport

129 Indirect damages The damage arising from disruptions to economic and social activities. Includes the cost associated with emergency response, clean-up, community support, as well as disruptions to transport, commerce and employment. Intangible damages Damages that are hard to quantify or measure in monetary terms. It includes impacts like stress, anxiety, loss of life and loss of memorabilia. Integrated water management (IWM) Is an approach which considers all components of the water cycle as a whole to maximise social, environmental and economic outcomes. It achieves this through the coordinated management of drainage, flooding, waterways, water supply and sewerage services. Local catchment A small catchment of less than 60ha. In some rural areas councils manage flood and drainage infrastructure for catchments of up to 200ha in size, due to historical arrangements. Floodwaters and stormwater from local catchments discharge into regional flood infrastructure, pipes and waterways. Locally and regionally appropriate flood management approaches The approaches chosen to minimise current or future flood risks in a local area, through flood managers working with the local community to determine the most effective and commercially viable approaches to reducing flood risks and their impacts. (This includes consideration of regional needs.) Minimise Measures taken to lessen the impact of a flood event. Mitigate Measures taken to reduce the likelihood or consequence of a flood event. Non-structural solutions Any non-physical measure used to reduce the consequences of flooding. This includes community education programs, training, insurance, planning and development controls, warning and emergency planning and emergency response. People directly affected by flooding People living, working or operating businesses within known flood-prone areas, who could sustain loss or damage. Prevention, preparation, response, recovery (PPRR) Prevention, preparation, response and recovery is an approach to emergency risk management that aims to reduce the likelihood and consequences of emergency situations like floods. An outline of the PPRR approach is: Prevention: the actions taken to reduce or eliminate the impacts of an emergency before it happens Preparation: the steps taken to minimise the consequences of an incident and ensure effective response and recovery times Response: activities undertaken to combat emergencies and provide rescue and immediate relief services. Recovery: taking steps to help affected people and communities achieve a proper and effective level of functioning. The PPRR approach is used by emergency services in Victoria to respond quickly and effectively to emergency flood events. Regional catchment A catchment, often including several local catchments, larger than 60ha or greater in size. (In some rural areas councils manage flood and drainage infrastructure for areas up to 200ha in size, due to historical agreements.) Residual risk The level of risk a community is exposed to after flood mitigation measures have been put in place. Resilient People or communities who have a strong understanding of their risks and take active steps to prevent or reduce the impact of floods. A resilient community is better able to withstand a crisis event and has an enhanced ability to recover from the impacts. Risk assessment The process used to determine the level of risk at a particular location by quantifying both likelihood and impact of floods. Flood managers use this process to determine management priorities. Structural solutions Physical measures used to minimise the likelihood and impacts of flooding. This includes channels, retarding basins and water storage, house raising, flood gates and more. Urban infill/consolidation The development of higher-density residential and commercial properties in existing urbanised areas of the city. Draft Flood Management Strategy Port Phillip and Westernport 41

130 Acronyms AAD Annual average damages ICA Insurance Council of Australia AEP Annual exceedance probability IWM Integrated water management BoM EMV DELWP DHHS FRAF Bureau of Meteorology Emergency Management Victoria Department of Environment, Land, Water and Planning Department of Health and Human Services Flood risk assessment framework MAV MPA MW PPRR PSP VICSES Municipal Association of Victoria Metropolitan Planning Authority Melbourne Water Prevention, preparation, response, recovery Precinct structure plan Victoria State Emergency Service Bibliography Australian Government Attorney-General s Department Emergency Management 2013, Managing the Floodplain: a guide to best-practice flood risk management in Australia, Handbook 7, 2nd ed, Australian Emergency Management Institute, Victoria. Bureau of Meteorology 2015, Flood Warnings Definitions and Terminology Council of Australian Governments 2011, National Strategy for Disaster Resilience, Commonwealth of Australia, ACT. Department of Environment, Land, Water & Planning 2015, Revised Draft Victorian Floodplain Management Strategy, Victorian Government, Melbourne. Department of Environment, Land, Water & Planning, Victoria Planning Provisions, Department of Environment, Land, Water & Planning, State Planning Policy Framework, Department of Environment, Land, Water & Planning, Victorian Coastal Inundation Dataset, Department of Environment and Primary Industries 2013, Improving our Waterways: Victorian Waterway Management Strategy, Victorian Government, Melbourne. Department of Transport Planning and Local Infrastructure 2013, Plan Melbourne: Metropolitan Planning Strategy 2014, Victorian Government, Melbourne. Department of Treasury and Finance 2011, Victorian Economic and Financial Statement 2011, Victorian Government, Melbourne. 42 Draft Flood Management Strategy Port Phillip and Westernport

131 Bibliography continued Emergency Management Victoria 2014, Interim Emergency Management Strategic Action Plan (2014/15), Victorian Government, Melbourne. Melbourne Water 2013, Healthy Waterways Strategy, Melbourne Water, Docklands. Melbourne Water 2013, Stormwater Strategy, Melbourne Water, Docklands. National Emergency Management Committee 2011, National Strategy for Disaster Resilience, Commonwealth of Australia, ACT. National Flood Risk Advisory Group 2008, Flood Risk Management in Australia, The Australian Journal of Emergency Management, Vol. 23 No. 4 Parliament of Victoria 2012, Environment and Natural Resources Committee Inquiry into Flood Mitigation Infrastructure in Victoria, Parliamentary Paper No 169, Victorian Government, Melbourne. Pilgrim, DH (ed) 1987, Australian Rainfall and Runoff A Guide to Flood Estimation, The Institution of Engineers, Barton, ACT Rockefeller Foundation 2015, Resilience Description, Victorian Climate Initiative 2014, Victorian Climate Initiative Annual Report 2013/14, Victorian Climate Initiative, Victoria. Victoria Coastal Council 2014, Victorian Coastal Strategy 2014, Victorian Government, Melbourne. Victorian Government 2012, Victorian Emergency Management Reform White Paper, Victorian Government, Melbourne. Victorian Government 2013, Victorian Climate Change Adaptation Plan, Victorian Government, Melbourne. Victorian Government 2014, Victoria in Future 2014, Victorian Government, Melbourne. Victoria State Emergency Services 2012, State Flood Emergency Plan, Victoria. Draft Flood Management Strategy Port Phillip and Westernport 43

132 Melbourne Water 990 La Trobe Street, Docklands, Vic, 3008 PO Box 4342 Melbourne Victoria 3001 Telephone Facsimile melbournewater.com.au ISBN Pending Copyright May 2015 Melbourne Water Corporation. All rights reserved. No part of the document may be reproduced, stored in a retrieval system, photocopied or otherwise dealt with without prior written permission of Melbourne Water Corporation. Disclaimer: This publication may be of assistance to you but Melbourne Water and its employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication. Several images by David Dashwood used under Creative Commons license

133 Victorian Floodplain Management Strategy Revised Draft

134 Acknowledgement of Victoria s Aboriginal communities The Victorian Government proudly acknowledges Victoria s Aboriginal communities and their rich culture; and pays its respects to their Elders past and present. The government also recognises the intrinsic connection of Traditional Owners to Country and acknowledges their contribution in the management of land, water and resources. Aboriginal Scar Tree near Avon River in Gippsland. Source: D ELWP The State of Victoria Department of Environment, Land, Water and Planning 2015 This work is licensed under a Creative Commons Attribution 3.0 Australia licence. You are free to re-use the work under that licence, on the condition that you credit the State of Victoria as author. The licence does not apply to any images, photographs or branding, including the Victorian Coat of Arms, the Victorian Government logo and the Department of Environment, Land, Water and Planning logo. To view a copy of this licence, visit Printed by On Demand Port Melbourne ISBN (Print) ISBN ISBN (PDF) Accessibility If you would like to receive this publication in an alternative format, please telephone the DELWP Customer Service Centre on , [email protected], or via the National Relay Service on , This document is also available on the internet at Disclaimer This publication may be of assistance to you but the State of Victoria and its employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication.

135 Contents Foreword 5 Executive summary 6 Section summaries Introduction 8 Part 1: Assessing flood risks and sharing information 8 Part 2: Avoiding or minimising future risks 8 Part 3: Reducing existing risks 9 Part 4: Managing residual risks Contribution to the development of the Strategy 12 2 Flooding in Victoria 13 3 The strategic approach 14 4 Purpose of the Strategy 15 5 A short history of floodplain management 15 6 Aligning with the Victorian and national approaches to disaster resilience 17 7 Aligning with the national flood warning arrangements 19 8 Adapting to a changing climate 20 9 Working with the environment to hold and slow floodwater 21 Part 1: Assessing flood risks and sharing information Flood risk metrics Annual exceedance probability (AEP) Population exposed to flood hazard Average annual damage Sharing flood risk information Flood data Flood maps Victorian flood databases Regional floodplain management strategies Involving all stakeholders Flood risk assessments Detailed flood risk evaluations (flood studies) Evaluating mitigation options Incorporating changing rainfall patterns into flood studies Taking account of Aboriginal cultural heritage in risk assessments Taking account of environmental watering 32 Part 2: Avoiding or minimising future risks Mitigating flood risks through planning and building The threshold flood risk in the built environment: the design flood event Victoria s land use planning system State and regional planning Local planning Planning for safe access during floods Existing planning coverage 38 Revised Draft Victorian Floodplain Management Strategy 3

136 13.7 Streamlining land use planning The building system Planning for stormwater management in Melbourne and regional centres Planning around coastal flooding The Interaction between coastal processes and coastal flooding Identifying risks at the regional level Supporting adaptation responses Planning for rising sea levels 43 Part 3: Reducing existing risks Flood warnings An overview of the future arrangements Flood warning services for all Victorians The Total Flood Warning System concept Assessing Total Flood Warning System service at state, regional and local levels Matching Total Flood Warning System services with community needs Review Working towards flash flood warning services Flood mitigation infrastructure An overview of the future arrangements Establishing new flood mitigation infrastructure Bringing existing regional urban infrastructure into formal management arrangements Bringing government-built rural infrastructure into formal management arrangements Maintaining levees that are not formally managed Dam operations Cross-border issues Flood mitigation activities on waterways An authorisation framework for flood mitigation activities on waterways Linkage with the rural drainage strategy Business continuity plans for critical infrastructure 65 Part 4: Managing residual risks Flood insurance Disclosing flood risk information Comprehensive flood mapping Vendor disclosure statements Integrated flood emergency management Incident control Managing residual water Planning for delivery of the Strategy Implementation plan Your chance to have a say Next steps 73 Acronyms 74 Glossary 75 Bibliography 80 Legislation 81 Revised Draft Victorian Floodplain Management Strategy 4

137 Foreword As Chair of the Interdepartmental Stakeholder Reference Group (ISRG), I am delighted to begin work on this new and important stage of consultation of the Victorian Floodplain Management Strategy. On behalf of the ISRG, I would like to thank everyone who contributed to the development of the Revised Draft Strategy. I also thank Environment, Climate Change and Water Minister Lisa Neville for her commitment to further engage with key stakeholders on the proposed policies, actions and accountabilities in the revised draft. The ISRG is interested in stakeholder views on the key revised areas including: revised rural levee policy to accommodate local government concerns an acknowledgement of Victoria s Aboriginal communities updates to the chapter relating to stormwater flooding in Melbourne and regional Victoria opportunities to identify hot spot areas subject to risk of stormwater flooding through regional floodplain management strategies and to pursue opportunities to provide flash flood warnings a new section relating to adapting to climate change to manage flood risk a new section on working with the environment to hold and slow floodwater clarification around emergency management roles and responsibilities clarification of responsibilities for maintenance of flood warning gauges consideration of the environmental benefits of flooding. We look forward to receiving feedback on this Revised Draft Strategy. In working together through this extended consultation process, I believe we will achieve an effective and balanced strategy for all stakeholders. Sharyon L. Peart Chair, ISRG The ISRG comprises representatives from agencies with floodplain roles and accountabilities including local councils and the Municipal Association of Victoria, catchment management authorities, the State Emergency Service, the Bureau of Meteorology and state government departments. Revised Draft Victorian Floodplain Management Strategy 5

138 Executive summary The Revised Draft Victorian Floodplain Management Strategy sets the proposed direction for floodplain management in Victoria. It builds on the technical basis of the 1998 Victoria Flood Strategy. The Revised Draft Strategy aligns with the Victorian Government s responses to the Victorian Floods Review and the parliamentary inquiry into flood mitigation infrastructure. It also aligns with the broader emergency management framework set out in the Emergency Management Act Importantly, it helps integrate floodplain management with the Victorian Waterway Management Strategy 2013 and the Victorian Coastal Strategy There are four key parts to this Revised Draft Strategy: 1. Assessing flood risks and sharing information provides the technical basis for assessing flood risk and commits to sharing flood risk information. It sets the framework to prioritise flood mitigation activities based on the level of flood risk. 2. Avoiding or minimising future risks endorses the use of planning controls to manage the potential growth in flood risk. It sets accountabilities in land use planning to avoid increased stormwater runoff from new developments and endorses planning benchmarks that consider predicted increases in sea levels. 3. Reducing existing risks clarifies the institutional arrangements to mitigate the risk and consequence of floods. It also explains how flood warning systems will be tailored to meet community needs. 4. Managing residual risks focuses on how access to better information can reduce the consequence of flood events. The response and recovery activities align the Revised Draft Strategy with the broader emergency management framework. Blue denotes areas affected by 1% AEP floods based on currently available mapping. HORSHAM PORTLAND Provide access to better quality mapping to support emergency services response and recovery. Pages MILDURA HAMILTON WARRNAMBOOL Assist councils to implement water management schemes for flood mitigation infrastructure. Page 52 SWAN HILL BALLARAT GEELONG Revised Draft Victorian Floodplain Management Strategy 6

139 Clarify the arrangements for flood warning systems, with DELWP as the oversight agency and providing direction for new flood gauges to be included as part of the water monitoring partnership. Pages Clarify the arrangements for the management of urban and rural flood mitigation Infrastructure. Pages Involve communities in flood mapping and management studies, local studies have been undertaken in a number of townships since the 2010 and 2011 floods. Pages WODONGA SHEPPARTON WANGARATTA BENDIGO! MELBOURNE!. BAIRNSDALE Plan for stormwater management to reduce smaller scale flooding over the medium to longer term. Pages TRARALGON Increase access to information to encourage flood insurance to be taken up commensurate with an individual s risk. Page 68 Provide guidance for preparing regional floodplain management strategies based on a risk assessment framework. Pages Encourage increasing land-use planning coverage for areas in the 1% Annual Exceedance Probability (AEP). Pages Revised Draft Victorian Floodplain Management Strategy 7

140 Section summaries 1-9 Introduction The introductory sections set the context for the Strategy. The focus is on communities and businesses becoming more involved in managing their own flood risks. This section highlights the environmental benefits of flooding and identifies opportunities to respond to a changing climate. A chapter on the history of floodplain management acknowledges the 1970s transition from structural mitigation efforts towards both structural and nonstructural measures. It recognises that the technical foundations of the 1998 strategy are still relevant. Part 1: Assessing flood risks and sharing information 10 Flood risk metrics Flood risk is a combination of the likelihood of a flood and its consequences when it does occur. Flood risk analysis involves understanding: the probability of flood events the population at risk the average annual damages associated with different events. Future flood maps will consider a range of floods and be updated periodically to take account of changes to flood risk. 11 Sharing flood risk information The Strategy identifies opportunities to share flood risk information with communities, businesses and emergency response agencies so that they can each better manage their risks. It recognises the value of local knowledge through community involvement in the flood studies that develop flood maps and gathering data before, during and after floods. Department of Environment, Land, Water and Planning (DELWP) will: set flood mapping standards to meet the purposes of a range of users maintain and continually improve Victoria s flood intelligence platform. 12 Regional floodplain management strategies Regional floodplain management strategies will provide the basis for assessing flood risk and setting regional priorities. DELWP is developing a risk assessment framework and guidance material to support catchment management authorities in developing regional strategies. This will include an assessment of: whether individual Total Flood Warning Systems (TFWS) are appropriately tailored to flood risks areas where flood risk is not considered in land use planning the potential needs for flood mitigation infrastructure areas that may require detailed flood risk evaluations Regional strategies will be developed in consultation with key stakeholders. It should be noted that while CMAs are currently in the early stages of developing regional floodplain management strategies, Melbourne Water will have a draft strategy prepared by mid Part 2: Avoiding or minimising future risks 13 Mitigating flood risks through planning and building Community resilience can be improved by using a mix of strategic and statutory planning tools. Land use planning and building controls are generally more cost effective than flood mitigation infrastructure, flood warning systems, flood education programs or flood emergency responses. The Strategy clarifies that the 1% Annual Exceedance Probability (AEP) flood will remain the design flood event to regulate new development and construction standards in Victoria, and that LGAs will remain responsible for ensuring that their planning schemes identify the areas at risk of a 1% AEP flood. Draft Planning Scheme Amendments will be prepared for the 1% AEP as outputs of local flood studies. Revised Draft Victorian Floodplain Management Strategy 8

141 This chapter applies a strategic and statutory approach to access flood-prone areas during floods. DELWP, in consultation with VICSES, the CMAs and Melbourne Water will develop guidance for the CMAs and Melbourne Water to draw on when advising LGAs on individual planning permit applications and strategic plans. 14 Planning for stormwater management in Melbourne and regional centres Integrated water management approach provides opportunities to manage urban flooding through, for example, stormwater and rainwater harvesting and reductions in the connection of hard surfaces to drainage systems. This chapter reiterates the existing requirements in Clause 56 of the Victorian Planning Provisions for new subdivisions to ensure that developments do not increase flows downstream of the site. There are also potential additional benefits to consider associated with the reuse of any stormwater captured as part of an integrated water management approach. 15 Planning around coastal inundation The primary causes of coastal inundation are storm surges combining with high tides (storm tides). Flooding can be worsened in estuaries by rainfall in coastal catchments and seasonal river mouth closures. This Strategy aligns with the Victorian Coastal Strategy (2014) and supports the draft regional coastal plans. LGAs will continue to make locally based decisions about managing the risk of coastal flooding in their role in assessing planning permit applications. Strategic local-based planning will be informed by relevant government policies and advice from local communities and experts on coastal flooding and coastal erosion. Part 3: Reducing existing risks 16 Flood warnings Effective flood warnings can help mitigate flood damage by providing communities and emergency response agencies with information about when a flood may occur and its likely severity. All Victorian communities receive a flood warning service, the nature of the service for a given community will be based on flood risks. Communities with high potential for flood damage already receive a more sophisticated level of service. This Strategy sets the framework to assess, establish, revise, operate, maintain and review Total Flood Warning Systems (TFWSs) tailored to flood risks and community need across Victoria. The Strategy identifies the roles of the various agencies involved in operating and maintaining a TFWS. 17 Flood mitigation infrastructure This section considers the management of flood mitigation infrastructure in Victoria. It is explicit about the role of LGAs in managing the infrastructure, and highlights the importance of managing infrastructure through formal management arrangements. The arrangements in place for Kerang and Nathalia, with the three levels of government contributing to the capital costs of the levee and LGAs paying for ongoing maintenance, should be seen as best practice where regional urban levees are required. Local communities should be involved in decision making about whether flood mitigation infrastructure is required. The Strategy identifies the circumstances where government may contribute to the capital costs of rural levees, sets out the process for assessing the need, and identifies the role of LGAs and the community in committing to the ongoing management and maintenance. DELWP will help LGAs and other authorities establish the administrative arrangements that will best enable them to manage flood mitigation infrastructure for the long term, including assistance on how to develop and implement formal management arrangements. Revised Draft Victorian Floodplain Management Strategy 9

142 LGAs may opt not to formally manage existing infrastructure. If so, their planning schemes must not assume that the infrastructure will provide any flood protection and they must plan for an emergency associated with its sudden and complete failure. For levees on Crown land, amendments to the Water Act 1989 have streamlined the approval process for landholders to manage those levees, with further amendments to the Planning Scheme making the administration even easier. This Strategy identifies Victoria s approach to cross-border collaboration to manage flood risks and coordinate emergency responses. 18 Flood mitigation activities on waterways The Victorian Waterway Management Strategy (VWMS) 2013 provides the framework for maintaining and improving the condition of Victoria s rivers, estuaries and wetlands. It aims to ensure that waterways continue to support environmental, social, cultural and economic values for all Victorians. Works on waterways undertaken for flood mitigation purposes (such as vegetation clearance, debris removal and sediment removal) need a CMA Works on Waterways permit. The Strategy proposes that DELWP will prepare guidelines for the CMAs to consider when assessing permit applications. Part 4: Managing residual risks 19 Business continuity plans for essential services The operators of essential-services infrastructure are responsible for developing and implementing sitespecific strategies to mitigate all risks to business continuity. The operators of essential-service infrastructure are accountable for: assessing the risks and consequences posed to their operations by flooding developing and implementing fit-for-purpose flood risk mitigation plans for each facility at risk of flooding developing fit-for-purpose flood response plans. 20 Flood insurance Governments have a role in ensuring that: individuals and communities affected by floods are able to recover and rebuild as quickly as possible people are able to choose where they live in an informed way (the relative size of flood insurance premiums in different locations provide an important signal) individuals and communities at risk of future flooding are aware of the risks and are able to obtain suitable protection against those risks, both in terms of having access to insurance and in benefiting from appropriate mitigation strategies. DELWP will work with the insurance industry to facilitate exchange of mapping and other flood risk information in order to ensure fair pricing of insurance. Revised Draft Victorian Floodplain Management Strategy 10

143 21 Disclosing flood risk information Floods with probability lower than the 1% AEP flood event will cause significant damage. While the costs of mandating higher floor levels for new buildings would be hard to justify outside the 1% AEP flood, it is important for people living and working in those flood-prone areas to be able make informed decisions about risk management. Emergency services and their communities need to be able to plan for flooding beyond the 1% AEP event. They need to be able to issue accurate and timely warnings. To encourage property owners to take an active interest in ensuring that their insurance premiums are tailored to their flood risks, the Victorian Government will seek to provide flood risk information beyond the 1% AEP. The Strategy supports Consumer Affairs Victoria in providing a trigger for individuals to complete due diligence relating to the flood risk before buying a property. 22 Integrated flood emergency management In Victoria, emergency management has been structured around three separate but interdependent components: Prevention: reducing or eliminating the incidence or severity of emergencies and mitigating their effects Response: combating emergencies and providing rescue and immediate relief services Recovery: assisting of people and communities affected by emergencies to achieve an effective level of functioning. State-wide accountability for these three components needs to be assigned and tailored for particular hazards and organisations. DELWP, Melbourne Water and the CMAs have primary responsibility to work with LGAs and VICSES on flood prevention activities. VICSES is the control agency for flood in Victoria, a function that, in a major flood, is exercised by the Emergency Management Commissioner. The Department of Health and Human Services currently has primary responsibility for coordinating recovery activities. 23 Incident control VICSES has a lead role in flood response, with advice from DELWP, CMAs, Melbourne Water and the Bureau of Meteorology. VICSES, with support from DELWP, is accountable for setting the requirements for flood interpretative services to support incident controllers during floods. VICSES is accountable for ensuring arrangements are in place to access flood specialist expertise during floods. Emergency management agencies need to work with Aboriginal people to help ensure Victoria s emergency management arrangements take into account the risks to Aboriginal cultural heritage. 24 Managing residual water DELWP is accountable for maintaining guidelines for managing water that remains after flood peaks have passed. The risks to health, community wellbeing and regional economies mean that key decisions may be needed on if and when to remove residual water and when to stop. Interventions should stop once the risks have been reduced to tolerable levels. 25 Planning for delivery of the Strategy This chapter outlines the next steps of the Victorian Floodplain Management Strategy. It provides details on how to make a submission and sets out the arrangements for implementation of the Strategy. The final Strategy will provide details on how the Strategy will be funded. Revised Draft Victorian Floodplain Management Strategy 11

144 Introduction 1. Contribution to the development of the Strategy The Strategy has been developed with input from key stakeholders in floodplain management and the broader Victorian community. It draws on extensive consultation after the floods in Victoria in and builds on the existing government policy in response to a review of the Flood Warnings in Victoria and the Government s Response to the Victorian Floods Review (VFR) (See Figure 1). Following the release of the Draft Victorian Floodplain Management Strategy on 26 June 2014, feedback was sought from the community and key stakeholders. The aim was to identify opportunities to improve the Strategy. People and organisations provided their feedback directly by attending one or more of the 12 information sessions held in various parts of Victoria. Many also provided a written submission. Figure 1: Documents contributing to the development of the Final Strategy 2010/ 2011 floods Victorian Floods review Dec 2011 ENRC Inquiry into flood mitigation infrastructureaugust 2012 Review of the Flood Warnings & Response Final Report by Neil Comrie AO, APM 1 December 2011 Release of Draft Strategy for public comment mid-2014 Government s response to the ENRC Inquiry into flood mitigation infrastructure October 2013 Government s response to the Victoria Floods Review November 2012 Release of Revised Draft Strategy mid-2015 Proposed release of Final Strategy end 2015 Victorian Floodplain Management Strategy Revised Draft Ongoing implementation of Final Strategy Review of Final Strategy Revised Draft Victorian Floodplain Management Strategy 12

145 Introduction In total, 76 written submissions were received. Local Government Authorities (LGAs)made up the largest cohort of submitters, followed by state and regional river, land and coastal managers, and members of the public. Also represented were water authorities, the insurance and other industries, professional associations, special interest and lobby groups, emergency services and Traditional Owners (see Figure 2). The range of responses meant that feedback was received on most aspects of the Strategy, but some key themes were repeated across multiple submissions. Importantly, the feedback also identified some gaps in the scope of the Draft Strategy. These submissions informed the development of this Revised Draft Strategy and highlighted the need to further test stakeholder input into the revised proposed policies, actions and accountabilities. Figure 2: Breakdown of submitters to the Draft Strategy 1% 1% 3% 8% 7% 17% 7% 16% 41% 2 Flooding in Victoria Flooding is a natural hazard in Victoria. Whether floods are caused by high rainfall, storm surges or inadequate drainage, they can severely disrupt communities by causing injury, loss of life, property damage, personal hardship and disruptions to regional economies. It is a question of when, not if, floods will occur. Fortunately, the location, the scale of effects and the probability of occurrence can be estimated, with reasonable accuracy, for a range of floods. Understanding flood behaviour enables us to assess the likely costs of flooding. It also enables us to assess the benefits of different options for managing the community s exposure to flood risk. Flood risks are created by people s interactions with floodplains. Those interactions expose people, animals and the built environment to flood hazards. The higher the probability of floods occurring, and the greater the consequences of those floods, the greater the flood risk. Because the probability of floods of different heights Community and extents member can be estimated, it can also be LGA considered in decision-making. Floods are potentially the most predictable disasters confronting State and Victoria. regional river, land and coastal managers This Revised Draft Victorian Floodplain Management Water authorities Strategy sets out a systematic approach to evaluating Professional Victoria s associations, flood risks. special It also provides a systematic interest approach and lobby to groups sharing flood risk information Emergency with services the individuals, communities, government agencies and other organisations responsible Traditional for managing owners the various aspects of flood risk. Insurance profession Industry 6% Community member LGA State and regional river, land and coastal managers Water authorities Professional associations, special interest and lobby groups Emergency services Traditional owners 41% Insurance profession Industry Revised Draft Victorian Floodplain Management Strategy 13

146 Introduction 3 The strategic approach The lessons from the 2010, 2011 and 2012 flood emergencies, and the history of flooding in Victoria, highlight the need for a modern framework to manage floods, protect communities and save lives. It is critical that steps are implemented in the immediate future to ensure exposure to flooding does not increase significantly. This was demonstrated by the 2011 flood in Brisbane, which, in many places, was smaller than the 1974 flood yet the damage was nearly 10-fold greater. This is a stark example of what can happen when development occurs without due consideration of flood risk. Enhanced effort in municipal planning, supported by increased knowledge of flood hazards, will go a long way towards securing resilience to floods. Flood overlays need to be updated as soon as possible after new flood maps are produced to maximise the returns on investment in flood information. Government has a role to play, but communities and businesses must also act to manage their own risks. Beyond planning controls, communities and businesses must use knowledge about flood hazards to guide the placement and ongoing protection of essential-service infrastructure such as roads, power sub-stations, gas lines and telecommunications infrastructure. There are no quick fixes in reducing the damage caused by widespread flooding. Two centuries of development on floodplains and low-lying areas mean that legacy issues will remain into the future. The constant message in emergency management reforms is that the job is a shared responsibility. In practice, the focus needs to be on specific accountability. Flood emergency management relies on absolute clarity about who is accountable for what. Clear accountabilities must not be blurred by shared responsibilities. Responsibility is about ownership of an endeavour. Accountability is about being answerable for the outcome of those efforts. Responsibility can be shared; accountability cannot. This Strategy focuses on identifying accountabilities. The State Government is actively reforming and integrating emergency management across multiple hazards (e.g. fire and flood). However, response and recovery assistance cannot offset the damage caused by such emergencies. The government is therefore driving a focus on structural and nonstructural mitigation options to reduce the need for response and recovery. This Strategy reflects that drive. Attempts over the past century to use engineering solutions to mitigate flooding have had mixed results. The risks associated with unmaintained, low-construction-standard levee systems are high. Spending funds on levees, and other flood mitigation infrastructure, without understanding their full costs and benefits, doesn t make sense. It is time to rethink and reset the approach, working more with the environment to allow wetlands to reduce the impacts of flooding by holding and slowing floodwater at appropriate times. More focus is required on providing certainty around the ongoing management and maintenance of flood mitigation infrastructure. Apart from the risks of levee failure, there remains a real likelihood that levees may overtop. Regular auditing of the infrastructure and its maintenance is required. These risks must be documented, communicated and incorporated into municipal emergency planning. Flooding within urbanised environments is a further legacy issue. Development on old creek lines and associated impervious urban surfaces have increased rainfall runoff, causing damage and disruption. Opportunities to reduce flooding through improved integration of water and urban planning need to be explored. The role of insurance in reducing exposure to flooding for communities and businesses, as well as government, cannot be over-estimated. However, insurance policies must be affordable and be priced to reflect the true nature of the risk. Once again, knowledge of the flood risk is fundamental. Insurance provides the opportunity to reduce the exposure to the consequences of legacy decisions; it will also guide future development on floodplains as improved understanding of flood behaviour influences premiums. Technology enables forewarning of potential floods to a much greater extent than ever before. Weather forecasting services are widely available and are broadcast on mainstream media. Individual stream gauge information is available online. Coupled with online weather radar services, this information helps people make judgements about looming floods. If the community flood risk is great enough, these basic services can be supported by more comprehensive flood warning systems. Revised Draft Victorian Floodplain Management Strategy 14

147 Introduction There will still be a need for localised flood warnings (driven by local knowledge and community networks), even in those areas of high risk where there are more sophisticated formal flood warning systems. Communities along more than 100,000 km of rivers and creeks in Victoria need different levels of warning service to reflect their different risks. Planned levels of warning service must be documented, maintained and communicated to communities to ensure they have the capacity to use the information provided during a flood. Local knowledge is invaluable in helping to better understand flood behaviour and the options for flood mitigation infrastructure. Local knowledge helps identify gaps in warning systems and provides a reality check when validating information on flood behaviour. It is government s role to provide opportunities to capture the wealth of local knowledge. Community consultation will continue with the development of regional floodplain management strategies; it will help identify gaps and set regional priorities. Community involvement in local flood studies will also help gauge the community s willingness and capacity to pay for ongoing mitigation costs. Understanding potential changes in flooding in a changing climate is evolving. Decision-making must be responsive to the latest scientific information. 4 Purpose of the Strategy This Strategy builds on lessons from the 2010 to 2012 floods and the history of flooding in Victoria. It aims to use those lessons to shape the future of effective floodplain management in Victoria. By providing a consistent statewide framework for the management of flood related issues, it aims to inform consistent decisions and actions over the next 10 years. The Strategy s vision and objectives are described in Figure 3 along with the expected outcomes. The effectiveness of this Strategy will be measured by how well it delivers those outcomes. 5 A short history of floodplain management Waterways and floodplain areas have always been important places for Aboriginal people to come together as families and communities for cultural, social and recreational activities. Access to floodplain areas is vitally important for these activities to continue and for future generations of Aboriginal people to learn about their culture. Traditional Owners talk about waterways moving back and forth across floodplains over time, effectively scattering artefacts and influencing the way cultural practices are undertaken. Victoria s early European settlers also valued access to rivers and streams for water supply, transport, fertile soils and waste disposal. Many settlements along rivers and streams grew into substantial but flood-prone communities. The settlers became increasingly aware of their flood risks in the late 1800s. Their initial response was to build levees that, at the time, were not subject to planning controls or engineering construction standards. Typically, these early levees were built to poor standards with unsuitable soils and significant failures were common during floods. Moreover, the nature of flooding was not well understood and levees were often constructed too close to waterways. They constricted the floodplains, causing high-energy, erosive flows rather than taking advantage of the floodplain s natural capacity to slow down, convey and store floodwater. Until the widespread major floods of , floodplain management in rural Victoria was largely a local government responsibility; state government agencies had very little involvement. The institutional arrangements were changed dramatically in 1975 when government agencies were given statutory functions to delineate flood prone land, and building regulations were strengthened. This approach was codified in the 1978 handbook, Flood Plain Management in Victoria. It ultimately led to the systematic use of flood studies, disciplined evaluations of flood mitigation and acquisition of the skills necessary to provide flood advice to LGAs. Even without today s sophisticated computer models, the flood studies of that time helped transform people s understanding of floods. Rather than continuing the practice of attempting to clear floodwaters as quickly as possible, engineers started to mimic nature by slowing the floodwater. They did this by building retarding basins and by recognising Revised Draft Victorian Floodplain Management Strategy 15

148 Introduction Figure 3: Vision, objectives and outcomes of the Draft Floodplain Management Strategy VISION Victorian communities, businesses and government agencies are aware of flooding and are actively taking measures to manage their flood risks to minimise the consequences to life, property, community wellbeing and the economy OBJECTIVES Encouraging communities to take action to manage their own risks (Reducing existing risks) Reducing legacy issues to minimise exposure to future flood risk and consequences (Reducing existing risks) Not making things worse (Avoiding or minimising future risks) Providing support to emergency services by focusing on prevention activities (Managing residual risks) OUTCOMES Resilient communities taking ownership of flood mitigation Local knowledge Incorporated in all aspects of planning for and responding to floods Local communities determining their own flood service needs, such as the need for mitigation infrastructure Communities accessing and acting on high-quality flood risk information Local communities actively involved in the flood studies being undertaken for their flood-prone towns Communities enabled to maintain levees on Crown land. Insurance affordability driven by an informed market Priority flood-prone areas in Victoria covered by highquality flood maps Flood mitigation infrastructure built and maintained where it is cost effective Ongoing management and maintenance arrangements for flood mitigation infrastructure Benefiting communities contributing to the capital costs, and the ongoing maintenance and management costs,of flood mitigation infrastructure Individuals maintaining levees on Crown land under streamlined arrangements. Development certainty underpinned by better coverage of land use planning tools Whole-of-water-cycle management helping to manage the long-term potential impacts of overland flooding in larger urban centres The Victorian Flood Database providing ready access to high-quality flood data. The Flood Intelligence Platform providing emergency managers with high-quality decision support services Community networks providing dependable flood information to emergency managers during floods Total Flood Warning Systems providing floodprone communities with services matched to their risks Accountability and auditing regime to provide a better understanding of risks of failure Emergency management planning underpinned by high-quality information. Revised Draft Victorian Floodplain Management Strategy 16

149 Introduction the benefits of maintaining access to the natural flood-storage capacity of floodplains. At the same time, LGAs started to introduce planning controls to avoid or at least minimise the growth in future flood risks. Gradually, Victorians recognised the need for an overall floodplain management strategy embracing a mix of structural and non-structural measures to deal with flood risks. In 1998, the landmark Victorian Flood Management Strategy codified the accumulated wisdom of best practices in floodplain management to that date. The 1998 strategy remains directly relevant to the contemporary challenges of floodplain management in Victoria. Its technical basis is still sound and will continue to be used into the future. This enduring foundation means that the challenges for the 2015 Victorian Floodplain Management Strategy are not technical, they are institutional. For example, there is an opportunity to strengthen the role of one of the 1998 strategy s programs, land use planning. Melbourne Water s collaborations with LGAs in Melbourne provide an example of how it is possible for land use planning to be applied throughout a region. There are still significant opportunities on large parts of Victoria s rural floodplains to increase the coverage of appropriate planning controls. This Draft Strategy must ensure that those remaining areas are covered. Two other 1998 strategy programs flood warning systems and flood mitigation infrastructure are driving reforms in Victorian floodplain management, triggered by the devastating consequences of the floods. The Victorian Floods Review (VFR) and the Parliamentary, Environment and Natural Resources Committee (ENRC) Inquiry into Flood Management Infrastructure enabled the Victorian Government to set processes in train that will ensure Victoria is better protected for the future. This Strategy proposes actions and policies that will help to implement the Victorian Government s response to those inquiries. It also develops institutional arrangements to ensure continual improvement in all aspects of floodplain management. 6 Aligning with the Victorian and national approaches to disaster resilience This Strategy marks a new era in floodplain management. It has been developed in consultation with all the agencies involved in floodplain management. It focuses on flood prevention and mitigation activities aligned with water portfolio functions under the Water Act But it is more than that: it specifies how those activities will dovetail with activities under other portfolios (see Figure 4). The 2009 National Strategy for Disaster Resilience describes a disaster-resilient community as one that works together to understand and manage the risks it confronts. It further states that disaster resilience is the collective responsibility of all sectors of society, including all levels of government, business, the non-government sector and individuals. The National Strategy initiated a national review of land use planning and building codes to consider ways to enhance disaster resilience in the built environment. The Victorian Floodplain Management Strategy responds to the National Strategy by: developing systems and processes to improve the quality of flood maps developing maps that show a range of flood probabilities, to better regulate land use in areas liable to flooding considering appropriate changes to land use planning and building codes ensuring that local inputs are considered when developing solutions to local issues. The 2012 Victorian Emergency Management Reform White Paper reinforces the all-hazards all-agencies approach to emergency management. Strategic priorities include building community disaster resilience and streamlining governance arrangements. Revised Draft Victorian Floodplain Management Strategy 17

150 Introduction Minister for Local Government Figure 4: Links to activities undertaken by other portfolios Minister for Environment, Climate Change and Water Minister for Planning Victorian Coastal Council Coastal Strategy DELWP # DELWP DELWP VICSES Minister for Emergency Services (Flood recovery activities for all emergencies is currently delegated to DHHS) STATE Regional Coastal Plans Support and Improve coastal management and planning in Victoria Victorian Waterway Management Strategy Regional Waterway Strategies # Aboriginal engagement requirements Victorian Floodplain Management Strategy #* Aligns with broader emergency management framework Sets floodplain management policy direction and accountabilities Regional Floodplain Management Strategies Policy and VPP (SPPF) Sets the framework for strategic direction for LUP in Victoria State Flood Emergency Plan #* Sets framework for preparedness and response arrangements for floods Regional Growth Plans Regional Flood Emergency Plans REGIONAL Local Councils CMAs # Coastal Adaptation Plans Prepare plans and hazard assessments of local areas to identify need for works and measures to manage risks Determine areas of priority in relation to waterway management Issue permits for floodplain management purposes and flood mitigation works Set regional floodplain management priorities based on state-wide risk assessment framework, in consultation with key stakeholders #* CMAs and/or local councils Local Flood Studies Identify flood mitigation responses Set strategic planning approach to land use in Victoria s regional areas identifies priority development areas Local Councils Local Councils Local Councils Set preparedness and operational arrangements for floods Collecting new flood recovery data (Feedback to state and regional level floodplain management strategies) LOCAL CMAs issue permits for mitigation works #* Role in providing community services Manage formal processes to construct and manage flood mitigation infrastructure #* Local Planning Policy Framework (LPPF) Municipal Strategic Statements set local objectives and strategic directions Apply appropriate zones and overlays to manage flood risks Municipal Emergency Management Plans Set the operational arrangements for floods in local areas Prepared with community input Shared responsibility between local and State Governments # Indigenous * Interface with broader Emergency Management Framework, flood, fire, tsunami, terrorism, etc Revised Draft Victorian Floodplain Management Strategy 18

151 Introduction The Emergency Management Act 2013 implements many of the reforms from the White Paper, repealing most of the 1986 Act. The reforms in the 2013 Act include: formally establishing the State Crisis and Resilience Council as Victoria s peak emergency management advisory body establishing Emergency Management Victoria (EMV) as the responsible agency for the coordination and development of whole-ofgovernment policy for emergency management in Victoria establishing the Emergency Management Commissioner (EMC) as the successor to the Fire Services Commissioner with an over-arching management role for major emergencies establishing the Inspector General for Emergency Management to provide assurance to the Government and the community regarding Victoria s emergency management arrangements. Victoria follows the National Approach set out in the Australian Emergency Management Handbook from a flood study to on ground action. 7 Aligning with the national flood warning arrangements The National Arrangements for Flood Forecasting and Warning are being developed as part of the Standardisation of Bureau of Meteorology (BoM) Services task force that reports to the Australia and New Zealand Emergency Management Committee. The document provides the Australian community and key stakeholders with a summary of how flood forecasting and warning services operate across Australia. The arrangements describe a collaborative approach involving all levels of government. They outline the roles and responsibilities of each level of government in providing and supporting an effective flood warning service, along with the legislative and administrative arrangements that influence the activities of the various agencies involved. The document includes a separate chapter for each state and the Northern Territory describing the specific arrangements and agency roles that apply in each jurisdiction. The Flood Warning Consultative Committee (FWCC) is an advisory body, reporting to BoM and participating state and local government agencies as required. The Victorian FWCC was formed in late 1989 and is chaired by BoM s Regional Director for Victoria; membership includes representation from state and local government agencies. The committee s overall role is to coordinate the development and operations of the state s flood forecasting and warning services. Its terms of reference are to: identify requirements for new and upgraded flood forecasting and warning systems establish the priorities for the requirements that have been identified using risk based analyses of the Total Flood Warning System (TFWS) annually review and provide feedback on the Service Level Specification for the BoM s Flood Forecasting and Warning Services coordinate the implementation of flood warning systems in accordance with appropriate standards promote effective means of communication of flood warning information to the affected communities monitor and review the performance of flood forecasting and warning services build awareness and promote the TFWS concept. Revised Draft Victorian Floodplain Management Strategy 19

152 Introduction 8 Adapting to a changing climate Victoria s weather and climate can change in response to a wide range of natural and human factors. Day-to-day changes in weather are the result of relatively random atmospheric fluctuations. Climate variations that occur from year-to-year are largely linked to large-scale ocean-atmospheric fluctuations. Longer-term changes are linked to a range of factors decadal to multi-decadal fluctuations in the Pacific Ocean and over much longer time scales, changes in the earth s orbit. In addition to these natural processes, factors such as greenhouse gases, aerosols, stratospheric ozone depletion and land use change also affect weather and climate. The Victorian Climate Change Adaptation Plan (2013) sets out projected changes in Victoria s climate. The projections suggest an increased risk of floods, bushfires, heat waves, drought, sea level rise and coastal hazards. That plan explains how the government will manage the risks of a changing climate including flood risks. Recent experience highlights the variability of Victoria s climate. The prolonged drought from 1997 to 2009 was the worst on record. It was followed by severe floods in western and northern Victoria. Victoria s climate variability is influenced by three global-scale factors, all of which were aligned in their wet phases for spring and summer in These factors are: the El Nino Southern Oscillation (ENSO), which characterises atmosphere-ocean interactions across the Pacific Ocean the Indian Ocean Dipole (IOD), which characterises atmosphere-ocean interactions in the Indian Ocean the Southern Annular Mode (SAM), which characterises the intensity and position of higherlatitude westerly winds and associated storm systems. Research indicates the SAM is trending towards a phase associated with decreased winter rain and increased spring and summer rain. The near-record high SAM in 2010, through its interaction with ENSO, played a significant role in the extreme rainfall of that spring. The Victorian Climate Initiative (VicCI) was established in 2013 to improve the understanding of the climatic system and its effect on water availability in Victoria. VicCI is a partnership between DELWP, BoM and CSIRO. It builds on the results of the South Eastern Australia Climate Initiative, which ran from 2006 to Through VicCI, the Victorian Government is investing in research to improve seasonal climate predictions, improve the understanding of past climates, our climate projections for the future and the associated risks to water resources. The Australian Government is funding an update of Australian Rainfall and Runoff (ARR) the national guideline for the estimation of design flood characteristics in Australia. The Victorian Government is participating in that update, by providing data, expert review and assistance with the coordination of the testing program. The new edition of ARR will provide guidance on how to incorporate changing rainfall patterns, storm surge and sea level rise into flood risk assessments (sections 12.4 and 15.1). DELWP is also an end-user partner of the Bushfire and Natural Hazards Cooperative Research Centre (BNHCRC). Its research supports the development of cohesive, evidence-based policies, strategies, programs and tools to build a more disaster resilient Australia. One of its coastal projects is developing better predictions and forecasts for extreme water levels arising from storm surges, surface waves, continental shelf waves, tsunamis and mean sea level rise. Another BNHCRC project is researching improved predictions for severe weather. It will use highresolution modelling, together with the full range of meteorological data, to better understand and predict fire weather, tropical cyclones, severe thunderstorms, and heavy rainfall. Anticipated changes in the intensity of storms and in average stream flows may be greater under different climate scenarios, and the variability from year to year may increase. This could shift the likelihood and Revised Draft Victorian Floodplain Management Strategy 20

153 Introduction consequence of floods in different parts of Victoria. These issues must be considered when assessing and treating flood risk. While our understanding of the effects of climate variability and a changing climate on future wet and dry cycles will continue to improve over time (section 12.4), uncertainty about future rainfall requires preparation for a range of climate conditions. The Victorian Government recognises the importance of working with research institutions and other governments to better understand and adapt to a changing climate. DELWP plays its part through improved access to flood information and through flood conferences and forums. DELWP will continue to seek out new knowledge and to share knowledge amongst floodplain management agencies to enhance flood management capability. The Australian Government s Regional Natural Resource Management Planning for Climate Change Fund is helping CMAs update regional plans to account for climate change. It will also support research to produce regional level climate change information. This Strategy deals with a changing climate by: incorporating changing rainfall patterns into flood studies (section 12.5) periodically revising flood studies (in accordance with the priorities established in regional floodplain management strategies section 12), to take account of revisions of the statistical estimates for floods of different magnitudes. following the advice about climate change boundaries and climate scenarios in the most recent edition of Australian Rainfall and Runoff A Guide to Flood Estimation providing guidance on how to apply current planning benchmarks for sea level rise (section 15.4). 9 Working with the environment to hold and slow floodwater Wetlands reduce the impacts of flooding by holding and slowing floodwater. They also act as sediment traps that filter nutrients from catchments and help to protect the water quality of rivers, estuaries and marine areas. In recognition of these benefits, many new wetlands have been constructed in urban areas to offset the increased runoff associated with the growth in impervious surfaces. By aligning with the Victorian Waterway Management Strategy (VWMS), this Strategy adopts the principle that rivers should, wherever possible, be allowed to flood naturally, maintaining connectivity to floodplains and their associated wetlands. Regional Floodplain Management Strategies (section 12) need to integrate the management of flood risks with the protection of priority high-value waterways identified in Regional Waterway Strategies. By allowing rivers to flood naturally, floodplain management can help to improve riparian ecosystems. These are important in their own right, and are also important to Aboriginal people as sources of food and medicine and as sacred sites and meeting places. Connectivity between the river, fringing wetlands, floodplains and the ocean is also important for many fish species to complete their life cycles and for nutrient exchange between habitats. Flooding can also deliver long-term benefits to agricultural production. Floodwaters will recharge water storages (particularly in dry regions) and deposit silt that improves soil fertility. In some situations, works can restore the connectivity between rivers, estuaries and floodplain wetlands. Where individual wetlands have been isolated from overbank flows by infrastructure or past development, it is sometimes possible to restore connectivity by removing or bypassing blockages in flow paths (e.g. by installing a culvert under a road). However, before these works are undertaken, it is important to understand any costs and benefits to the local community, the feasibility of the works, the value of the wetland, the potential to integrate with environmental watering and the cost-effectiveness of the overall proposal. Revised Draft Victorian Floodplain Management Strategy 21

154 Part 1: Assessing flood risks and sharing information Flooded River Red Gums, Barmah Forest. Source: Sharada Ramamurthy Revised Draft Victorian Floodplain Management Strategy 22

155 Part 1 10 Flood risk metrics Flood risk is a combination of the likelihood of a flood occurring and the consequences when it does occur. Flood risks are the result of the ways in which people choose to use those parts of the landscape that flood. Flood risks vary with the frequency of exposure to flood hazards, the severity of the hazard, the vulnerability of the community, the vulnerability of the built environment and the vulnerability of the farming systems. Understanding these interactions can inform decisions about how to manage flood risks. Flood risks must be quantified to be able to rank their relative seriousness. This involves being able to measure in some way: the probability of flood events the population exposed to flood hazard the economic damage associated with different events Annual exceedance probability (AEP) Floods of different sizes cause different amounts of damage and the size of a flood is linked to the probability of its occurrence. That probability can be expressed in several ways. Floodplain managers tend now to refer to the probability each year of a certain size flood being equalled or exceeded; they refer to this as the percentage annual exceedance probability (AEP). The term AEP reinforces the fact that there is an ongoing flood risk every year regardless of how recently there was a similar flood. In contrast, the term average recurrence interval (ARI), where probability is expressed as a return period in years, is now actively discouraged. Technically, these terms are interchangeable, but psychologically ARI can be misleading. People can be tempted to think that if they experience a 1-in-100-year flood their property will then be safe for another 100 years. In reality, there is a 1% chance that they will experience a flood of the same size the next year. Flood studies (section 12.3) provide a sound technical basis for developing calibrated and verified computer models that consider historic floods. These models help us to understand the probability of floods of different sizes occurring and the impacts of floods of different probabilities. Models can also provide an understanding of the probability that floods of a similar size to past events will recur. The probability of a flood of a given size occurring remains the same from year to year unless the flood regime is altered ( e.g. by the presence of a new dam or levee system) or new data leads to statistical estimates being revised. Because both continue to change, flood studies must be renewed periodically and flood maps updated. Priorities for new and revised flood mapping will be identified through regional floodplain management strategies (section 12). Proposed Policy 10a The Victorian Government will apply mapping standards for all future flood maps included in Victoria s flood databases. Future flood maps will be designed to meet the needs of land use planning, emergency response planning, insurance assessments and the declaration of minor, moderate and major flood warnings where those flood class levels have been defined. Flood map contours will be linked to flood monitoring gauges, where they exist. Annual exceedance probability (AEP) The likelihood of the occurrence of a flood of a given or larger size occurring in any one year, usually expressed as a percentage. For example, if a peak flood flow of 500 m 3 /s has an AEP of 5%, it means that there is a 5% chance (i.e. a one-in-20 chance) of a flow of 500 m 3 /s or larger occurring in any one year. Revised Draft Victorian Floodplain Management Strategy 23

156 Part Population exposed to flood hazard Floods put people who live, work or travel on the floodplain at risk of social disruption, financial loss, disease, injury or possibly death. The nature of these risks can change with demographic trends and with the effectiveness of flood warnings and emergency responses. There are different ways to measure the population at risk, depending on the detail required. In general, the larger the population at risk, the more people who need to be warned and, if necessary, evacuated. The population at risk is not just about total numbers; it is also about vulnerability. Strategic land use planning and emergency management planning need to consider vulnerable sectors of the community at the local level. People in hospitals, nursing homes, schools, childcare facilities and corrective facilities are particularly vulnerable to flood, as are older people and people with limited mobility Average annual damage Floods are generally regarded as causing three types of damage: Direct tangible damages include damage to the structure and contents of buildings, agricultural enterprises and regional infrastructure. Indirect tangible damages arise from disruptions to community wellbeing, economic activities and social activities. They include the costs of emergency response, clean-up, community support, as well as disruptions to transport, commerce and employment. Intangible damages cannot be quantified in monetary terms, despite their significance. They include trauma, stress and the loss of cultural heritage, biodiversity and threatened habitats. Floods of different sizes cause different amounts of damage. For a given flood-prone area, the damage caused by floods of various magnitudes can be averaged to determine the average annual damage (AAD). AAD provides a basis for comparing the economic effectiveness of different structural and nonstructural mitigation measures. It allows the costs of mitigation to be compared with its benefits (in terms of reduced AAD). 11 Sharing flood risk information This section outlines the ways in which information about flood risks is shared with individuals, government agencies and other organisations so that each can play their part in flood emergency management Flood data Flood data collected after a flood provides valuable information on flood behaviour. Records of flood flows, flood depths, flood extents and flood behaviour are important for calibrating and validating computer models. They are collected from a variety of sources. Traditionally CMAs, Melbourne Water and DELWP have had significant roles in collecting and collating flood data and this needs to continue. However other agencies and individuals also collect data. A starting point for mapping the flood risk is to identify what flood data is available and where it can be obtained. Proposed Accountability 11a CMAs and Melbourne Water are accountable for identifying and prioritising post-flood data needs, in collaboration with DELWP. Proposed Action 11a DELWP will develop guidelines to encourage consistent standards for post-flood data collection. CMAs and Melbourne Water will use these guidelines to update their protocols and standards for data collection. Revised Draft Victorian Floodplain Management Strategy 24

157 Part Flood maps Flood maps are an output of flood studies (section 12.3). DELWP is responsible for developing consistent standards for mapping flood risks. Those standards now extend to flood mapping for a range of floods, not just the information required for planning and building controls. The standards will include requirements for local consultation during the preparation of flood maps and the incorporation of local knowledge. They will include Melbourne Water and the CMAs role in vetting and approving flood maps and other flood study outputs. Proposed Accountability 11b DELWP is accountable for preparing flood mapping standards to meet the needs of a range of uses, including land use planning, insurance and emergency response. DELWP and Melbourne Water are accountable for storage and custodianship of flood maps developed as part of government-funded flood studies and vetted by the relevant CMA or Melbourne Water. VICSES is accountable for providing DELWP with its requirements and specifications for flood mapping for emergency planning, emergency response and community education. In support of this commitment, DELWP will ensure that all new flood maps for urban and regional areas prepared with government financial assistance will: be developed in consultation with local communities to make use of local knowledge be informed by the most recent edition of Australian Rainfall and Runoff A Guide to Flood Estimation be of sufficient quality for inclusion in Municipal Planning Schemes take account, where relevant, of the State Planning Policy Framework (SPPF) strategies, including to plan for and manage the potential coastal impacts of climate change (section 15.4) be quality assured be stored in Victoria s flood databases Victorian flood databases The Victoria Flood Database (VFD) and Melbourne Water s Flood Database together provide for the systematic collection, collation, analysis and presentation of Victoria s quality-assured flood information. That information is available in geographic information system (GIS) formats. The quality of existing data is variable; it ranges from basic, historic and interpreted data through to the outputs of recent flood studies. Older flood study data and flood maps are updated as newer information becomes available. The databases are therefore in a state of continual improvement. The consultants producing flood studies are required to deliver data to the VFD as GIS layers in particular coverage formats. The VFD currently consists of 26 data layers. One of these of particular importance for land use planning shows the 1% AEP flood level. There are nine other flood layers providing flood levels for a range of events, from moderate to extreme, as well as historic levels. These other levels are critical for emergency management planning and response. They are also critically important in enabling insurance premiums to reflect risk accurately. Proposed Accountability 11c DELWP and Melbourne Water are accountable for maintaining and continually improving guidelines for the management of Victoria s flood databases. DELWP is accountable for maintaining and continually improving protocols for updating the data in the Victoria flood database. Proposed Action 11b DELWP and Melbourne Water will integrate the two existing databases to provide Victorians with a single point of entry to readily accessible and authoritative records of flood data in Victoria. Revised Draft Victorian Floodplain Management Strategy 25

158 Part Victoria s flood intelligence platform DELWP is developing a web-based flood intelligence platform to be the authoritative source of flood intelligence before, during and after floods. It will be used to bring together the outputs of weather forecast models, hydrologic models, hydraulic models, satellite observations and stream gauge data. Most importantly, the flood intelligence platform will bring together flood-consequence information at the property scale, where possible. As with other web-based mapping services, it will help agencies with flood emergency management functions to quickly and accurately visualise the problems they must manage in terms of both time and space. The platform will help improve flood warning, preparedness and response activities for at-risk towns. It will also enable emergency management agencies to share information during floods. In that way, it will support them in their endeavours to make real-time interpretations of likely flood behaviour, to coordinate flood responses and to assess flood impacts. It will help them provide better messaging to flood-affected communities. The flood intelligence platform will underpin, streamline and improve the efficiency of the flood interpretative services provided by DELWP, Melbourne Water and the CMAs to VICSES and LGAs. These agencies will use the information coming out of the flood intelligence platform to provide advice to flood-affected communities. Proposed Accountability 11d DELWP is accountable for maintaining and continually improving Victoria s flood intelligence platform. Proposed Action 11c DELWP, in consultation with Melbourne Water, CMAs, LGAs and the VICSES, will ensure the information in Victoria s flood intelligence platform remains current. All agencies carrying out self-generated flood mapping exercises will be encouraged to follow existing DELWP guidelines. On completion of such maps, LGAs will advise DELWP and provide a copy of the mapping for inclusion in the VFD. Once DELWP is assured that the quality of the data represents an improvement over that already in the Victorian Flood Database, it will make that information available to support emergency preparation and response. Revised Draft Victorian Floodplain Management Strategy 26

159 Part 1 12 Regional floodplain management strategies Regional floodplain management strategies interpret and apply the policies, actions and accountabilities outlined in this Strategy at the regional and local levels. They align the efforts of various agencies and communities to deliver the outcomes called for by this Strategy. Regional strategies start with an assessment of flood risks across the region. Those risks are then assessed against the regional community s tolerance for flood risks. A range of mitigation measures for intolerable risks are then explored. At the regional level, mitigation measures might include strategic plans for land use and for flood response arrangements. Regional strategies prioritise the actions necessary to put preferred mitigation measures in place. Priority is given to measures that do most to narrow the difference between existing flood risks and the community s willingness to accept those risks. The main role of regional strategies is to help all agencies with flood emergency management functions align their priorities. The process of prioritisation enables those partner agencies to align their potential to source and allocate funds towards priority actions over a three-year rolling implementation plan. At the local level, flood mitigation measures are usually investigated and assessed through detailed flood studies (section 12.3). Local mitigation measures might include improvements to total flood warning systems (TFWSs), changes to land use planning controls, changes to Municipal Emergency Flood Plans or improvements to flood mitigation infrastructure. The CMAs and Melbourne Water lead the development of regional floodplain management strategies in collaboration with their local communities, LGAs, VICSES, water corporations and other partner agencies. It is important that agencies take into account local knowledge when aligning their priorities. DELWP will develop guidelines for the preparation of regional floodplain management strategies. These guidelines will outline consistent methods for assessing flood risks and assessing the community s tolerance for those risks. The methods will align with the principles of the National Emergency Risk Assessment Guidelines. Proposed Policy 12a Victoria s floodplain management priorities will be established through regional floodplain management strategies. Proposed Accountability 12a Melbourne Water and the CMAs are accountable for developing and periodically reviewing regional floodplain management strategies in partnership with LGAs, VICSES and their local communities. Proposed Action 12a DELWP will develop guidelines to enable the preparation and review of regional floodplain management strategies. The CMAs and Melbourne Water will each prepare regional floodplain management strategies for their regions Involving all stakeholders The Victorian Emergency Management Reform White Paper makes it clear that: effective emergency response relies strongly on pre-existing cooperative networks built and maintained during preceding years. Preparing a regional floodplain management strategy provides Melbourne Water and the CMAs with an opportunity to foster networks and a culture of shared responsibility. It provides an opportunity to establish and align regional priorities for VICSES, LGAs, water corporations and community representatives. It also provides an opportunity to foster greater community involvement in the development and ownership of local plans. This is consistent with the National Strategy for Disaster Resilience. CMAs and Melbourne Water will also engage with emergency management agencies through existing regional emergency management planning frameworks. In this way they will participate in allhazards regional risk assessments. Their regional floodplain management strategies will be part of, and make use of, existing emergency management planning arrangements. Revised Draft Victorian Floodplain Management Strategy 27

160 Part Flood risk assessments Addressing flood risks should be determined on a priority basis to deliver maximum benefit. Figure 5 shows the framework for assessing priorities. Figure 5: State, regional and local risk assessment framework Provides funding contribution. Provides guidance for development of local flood studies. State Sets the framework to assess regional flood risks Determines state-wide priorities for investment based on outcomes of regional risk assessments. Regional Sets regional floodplain management priorities based on consistent risk assessment framework. Manages development of local flood studies. Local Identifies appropriate flood response based on risk Regional risk assessments Regional priorities for government investment in floodplain management need to be informed by structured and standardised analyses and judgements regarding the relative priority of flood risks throughout the region. To that end, DELWP has commissioned work to adapt and refine its existing Rapid Appraisal Methodology for setting regional priorities. The refined methodology will allow more rapid and consistent evaluation of floodplain management measures in a cost-benefit analysis framework Rapidity is required primarily because of the number of floodplain management programs requiring evaluation and because limited funds are available for the evaluation of those programs. Consistency is needed to ensure comparability between evaluations. A consistent approach to assessing the flood risks for different towns will enable communities with similar risks to be treated equitably. DELWP will ensure that this approach is consistent with the National Emergency Risk Assessment Guidelines. VICSES s Community Emergency Risk Assessment (CERA) approach is also used in municipal assessments. The CERA tool provides a robust framework for a community of interest to identify and prioritise those emergency risks that are likely to create most disruption to them. The assessment helps users identify and describe hazards and assess impacts and consequences based on the vulnerability or exposure of the community or its functions. Regional risk assessments will also identify those urban areas where stormwater-induced flash flooding poses a potential threat to life. That information will help guide priorities for urban stormwater reform in Victoria s major regional centres (section 14). It will also help to set priorities for flash flood warning services (section 16.7) State-wide risk assessment Once the regional floodplain management priorities are established, the next task is to set priorities at the state level. Again, there is a need for a structured and standardised methodology for making those judgements. Because all future regional risk assessments will be based on a consistent methodology it will be possible to rank those risks consistently at the state level. This will, in turn, allow for mitigation priorities to be set at the state level. Proposed Action 12b DELWP will refine a rapid and robust methodology for establishing regional floodplain management priorities in ways that allow statewide floodplain management priorities to be established. Revised Draft Victorian Floodplain Management Strategy 28

161 Part Detailed flood risk evaluations (flood studies) Floods are potentially one of the most predictable disasters confronting Victoria. Tools are available to analyse their magnitude, frequency and impact on the landscape. Predictions can be made, with varying degrees of precision, on how long before rain falling on a catchment aggregates into flooding on the floodplain. Floodplains are important and valued places to work and live and, while some areas can be protected from flooding or floor levels can be raised, it is not economical, feasible or even desirable to completely eliminate flooding. Protecting part of the floodplain from flooding will often increase flood impacts elsewhere. Flood damages and trauma can be reduced by using credible data about flood behaviour, such as flood heights, flood extents and flood probabilities. To collect that data continual improvement of contemporary knowledge of flood behaviour is required. Local risk evaluations, in the form of flood studies, can fill gaps in knowledge and help in considering flood management options. Their usefulness depends on their technical rigour. They can be done to different levels of complexity, depending on the outcomes required. High standards apply for complex flood situations with high and potentially increasing risk exposure. Less detailed investigations are used in areas where the population at risk is low and the AAD is low. CMAs and LGAs generally conduct flood studies in partnership. Their individual roles in any given flood study depend on their capacity and their history of teamwork. Regional floodplain management strategies will provide clarity about how the roles will generally be shared in each region. The costs are shared equally between LGAs, the Victorian Government and, it is expected, the Australian Government.* Flood studies must consider all sources of flooding in the study area, as well as the interactions between them. They must seek to: model the hydrologic inputs including rainfall and runoff that lead to floods of different sizes and calibrate these models against historic floods model the hydraulic behaviour of floods including flood heights, extents and velocities as they vary with time and calibrate these models against historic floods understand the varying hydraulic nature of the floodplain being studied understand the varying flood hazard within the floodplain assess the scale of potential flood damages for the existing community assess the potential for flood damage on areas of the floodplain that may be considered for future development assess the consequences of floods of different sizes. Case study: Natimuk Flood Investigation On 12 January 2011 more than 115 mm of rain fell on the Natimuk Creek catchment. Within a day, the small Wimmera town of Natimuk, between Horsham and Edenhope, was flooded. Residents tried to hold the floodwaters back with sandbags, but despite their best efforts water flowed through many homes and businesses. The rapidly rising water took everyone by surprise. The people of Natimuk were frustrated by the lack of information about how bad the flood was going to get; it came as a shock when authorities began to advise them to leave their homes. Wimmera CMA and Horsham Rural City Council have moved to better prepare Natimuk s 700 residents for future flooding. The Natimuk flood investigation was finished in early Between them Horsham City Council, the Victorian Government (through the CMA) and the Australian Government shared the total cost of $150,000. The people of Natimuk played an active part in the investigation; they provided local knowledge at community project meetings, shared ideas on the local Facebook page and debated options at the town s pub. The Natimuk community now has access to detailed flood mapping and information about a range of floods. The VICSES local flood guide shows accurate local flood maps and other information drawn from the investigation. Horsham City Council has worked with the Victorian Government and Wimmera CMA to install a stream flow gauge and rain gauge on the creek upstream of town. These gauges will send real time alerts about rising creek flows to a central location for dissemination to the community. * This expectation is subject to the Australian Government s continued provision of suitable funds. Revised Draft Victorian Floodplain Management Strategy 29

162 Part 1 Flood study outputs must be capable of being used by a variety of stakeholders. They are useful only if individuals, communities, government agencies and other organisations have access to, can understand, and act on, high quality information about the risks of flooding. The outputs should be integrated into the relevant flood database, where they can be made readily accessible Evaluating mitigation options There are several steps in moving from a flood study to on-ground action. In practice, the challenge is to determine how much of this work can and should be done in parallel rather than in sequence. This varies with the degree of difficulty involved in securing: viable risk management options consistency with legislation and with the policies of the partners involved integration with statutory planning community support priority in capital funding programs ongoing funding for management and maintenance inter-agency commitment to seeing the action plan implemented. As a general rule, the process should be condensed as much as practicable. It is important to capitalise on community receptiveness to flood mitigation options (including planning controls) especially if the planning is being done soon after a flood. If the process drags out too long, the risk is that essential community support will diminish. These processes are being accelerated significantly by ensuring that flood studies provide more than maps of flood levels for different flood events. Flood study outputs often now include: draft Planning Scheme Amendments (section 13.4) preferred elements for a Total Flood Warning System (section 16) preferred options for flood mitigation measures (section 17.2) drafts of the relevant components of the Municipal Flood Emergency Plan (section 22). Not every flood study will require all these outputs. For example, in sparsely populated rural areas, the main output might be a draft Planning Scheme Amendment. In such areas it might be that individual actions could involve constructing Case study: Corangamite Planning Scheme flood controls at Skipton The township of Skipton straddles the Mount Emu Creek about 50 kilometres west of Ballarat where the Hamilton Highway crosses the creek. The commercial centre of the town and many residential properties were severely flooded in September 2010 and January The 2011 flood was the worst on record and residents had limited information to guide them in preparing their properties for the impact. In early 2013, Glenelg Hopkins CMA and Corangamite Shire Council worked with the Skipton community to complete the Skipton Flood Investigation. Corangamite Shire Council, the Australian Government and the Victorian Government (through the CMA), jointly invested $140,000 in the project. The project showed that the construction of a physical flood barrier was not feasible it would have required a levee more than two metres high along the entire creek frontage. The Skipton community instead supported introducing floodplain planning controls to guide future development in the town and to help people identify areas at risk. Corangamite Shire Council and Glenelg Hopkins CMA worked together to develop controls tailored to the flood conditions at Skipton. Council moved forward with an amendment to the Corangamite planning scheme in 2013 and adopted the new controls into the scheme in early Source: DELWP Revised Draft Victorian Floodplain Management Strategy 30

163 Part 1 levees around dwellings and curtilages with minimal third-party impacts. If so, they will be covered through existing planning schemes. If they involve maintaining existing infrastructure on Crown land or activities on waterways, they will be covered by licensing arrangements (sections 17.4 and 18.1). Flood study outputs must provide flood-prone communities with concrete information about the real-world consequences of floods of different sizes. They must help the VICSES engage with flood prone communities as they think through their mitigation options, and engage with culturally and linguistically diverse communities through its FloodSafe Program. They must also help the VICSES to prepare Local Flood Guides that explain local flood risks and provide advice on how to prepare for and respond to floods Incorporating changing rainfall patterns into flood studies Victoria s weather and climate can change due to a wide range of natural and human factors (section 8). The knowledge about a changing climate, including changing rainfall patterns, continues to improve as further research becomes available. This evolving understanding of changing rainfall patterns needs to be incorporated into flood studies. As discussed in section 10.1, the probability of a flood of a given magnitude occurring or being exceeded remains the same from year to year unless the flood regime is altered or new data leads to a revision of the statistical estimates. Every year, new data is added to the climatic records. Over time, that accumulation of new data leads to a revision of the statistical estimates of flood probabilities. This includes the statistical estimates of the 1% AEP flood, which is important for land use planning (section 13.1). Australian Rainfall and Runoff A Guide to Flood Estimation, the primary reference for designing and calibrating the hydrological and hydraulic models at the heart of flood studies, is being revised. By mid-2015 it will include revised data and improved methods to estimate flows and flood levels from rainfall. The revised ARR will also deal with the selection of climate change boundaries. It will provide guidance on appropriate climate scenarios to consider as part of the development of regional floodplain management strategies Taking account of Aboriginal cultural heritage in risk assessments Floods and floodplain management activities can both present risks to Aboriginal cultural heritage. Regional flood assessments, local flood studies and flood mitigation works must take into account significant places, sites and landscapes. The Aboriginal Heritage Register is an invaluable resource, but it is important to recognise that Traditional Owners have a much broader information base about Aboriginal cultural heritage than is currently available to government. It is essential to consult with local Aboriginal communities in assessing and mapping flood risks. Regional floodplain management strategies will provide an opportunity to refine the relationships between natural resource managers and Aboriginal people; they will to help to ensure cultural values are properly reflected in floodplain management. In working with Traditional Owners to achieve this outcome, the CMAs and Melbourne Water will follow the consultation and engagement processes outlined in the Victorian Waterway Management Strategy (2013). Processes are also needed to ensure that significant Aboriginal cultural values are considered as part of the Incident Control arrangements outlined in section 23. This would require governance arrangements that formally include the provision of advice on Aboriginal cultural heritage considerations. Indigenous grinding grooves near the Avon River. Source: DELWP Revised Draft Victorian Floodplain Management Strategy 31

164 Part Taking account of environmental watering Flooding is a natural part of the flow regime for many rivers. Floods provide important physical connections between the channel and floodplain; for example, these events provide food and habitat for fish and other aquatic animals, help regulate water quality and trigger growth and regeneration of floodplain flora. The construction of large dams (known as river regulation), together with water extraction for consumptive use, has significantly reduced flows within river channels and the frequency with which floodplains are connected to rivers through flooding. The duration and size of floods has also been reduced. Over the past decade or more, State and Australian Governments have made significant investment to address the environmental impacts associated with river regulation and water extraction. The Victorian Environmental Water Holder and the Commonwealth Environmental Water Holder now hold significant water entitlements; their explicit objective is to return flows to river systems to achieve environmental outcomes without affecting private property. Primarily, the focus of environmental water holders is providing flows solely within the river channel, well below levels that pose a risk to private land or infrastructure. However, in some instances, it is also possible to actively deliver environmental water to the floodplain. This occurs mainly on public land such as National Parks and State Forests, but may also occur on private land, where the landholder has given consent. Environmental water holders work with the other environmental watering program partners, such as waterway managers and storage managers, to ensure that risks to third parties are appropriately managed in the delivery of environmental water. Where appropriate, this may include ceasing environmental water releases if significant rainfall and potential natural flooding were forecast. Lake Wallawalla Source Mallee CMA Revised Draft Victorian Floodplain Management Strategy 32

165 Part 2: Avoiding or minimising future risks Minor flooding in Paynesville, Gippsland Lakes. Source: West Gippsland CMA Revised Draft Victorian Floodplain Management Strategy 33

166 Part 2 13 Mitigating flood risks through planning and building All levels of government have recognised that land use planning can help to mitigate the threat from natural hazards. The Council of Australian Governments recognised in its National Strategy for Disaster Resilience that responsible land use planning can prevent or reduce the likelihood of hazards impacting communities, especially for new development. The Victorian Government s Emergency Management Reform White Paper also explains that: Community resilience can be improved by using planning approaches that consider likely risk factors and vulnerabilities, and identify how to mitigate against those risks. Land use planning policy must fully account for a location s risk profile to properly determine the nature and extent of new developments. The Victorian Floods Review (VFR) noted that land use planning and building controls were generally more cost effective than flood mitigation infrastructure, flood warning systems, education programs or emergency responses. One of the objectives of the Planning and Environment Act 1987 is to provide for the fair, orderly, economic and sustainable use and development of land. In that context, the Act also provides for planning schemes to regulate or prohibit any use or development in hazardous areas or in areas which are likely to become hazardous areas. Because it is possible to predict which land is at risk of flooding, it follows that it is prudent to regulate development in those areas to ensure it is compatible with flood risk. In so doing, the aim is to avoid or minimise the increase in future flood risks The threshold flood risk in the built environment: the design flood event In order to identify the areas that the planning and building systems should protect, it is necessary to decide which level of flood risk should be used. This risk is known as the design flood event (DFE). The Victorian Floods Review questioned if the 1% AEP flood should still be used as the DFE in Victoria. The Victorian Government has determined that the 1% AEP flood is the appropriate standard to regulate and protect new development through the planning and building systems. It has also determined that emergency and community facilities (including hospitals, ambulance stations, police stations, fire stations, residential aged care facilities, communication facilities, transport facilities, community shelters and schools) should be located outside these areas. The purpose of planning and building regulations is to ensure that proposed new developments and redevelopments have regard for the applicable flood risk. If the risk is judged to be intolerable, a development proposal may be rejected. However, in most cases development would be subject to conditions about appropriate floor levels, the siting of the building on areas of lowest risk, and the standard of building construction and the trafficability of accessways. Proposed Policy 13a The 1% Annual Exceedance Probability flood will remain the design flood event to regulate new development and construction standards in Victoria. Aerial view of floodwaters in the Victorian town of Rochester on 17 January Source: Newspix 13.2 Victoria s land use planning system Victoria s land use planning system operates through planning schemes, which are subordinate legislation under the Planning and Environment Act Planning Schemes set out policies and provisions for the use, development and protection of land. They are legal documents prepared by the LGA or other planning authorities, and approved by the Minister for Planning. Revised Draft Victorian Floodplain Management Strategy 34

167 Part 2 Planning Schemes must be prepared using the Victoria Planning Provisions (VPPs). The VPPs contain a comprehensive set of planning provisions for Victoria, including compulsory state and local policies and strategies, and zones and overlays used locally. This approach helps ensure that Planning Schemes are prepared in a consistent way State and regional planning Planning Schemes include a compulsory State Planning Policy Framework (SPPF), which sets out the statewide principles, policies and strategies for how land is be used and developed. Planning Schemes must also be consistent with the government s Regional Growth Plans, which are referenced in planning schemes. Regional Growth Plans recognise the impacts of natural hazards, including flood, and set strategies for development to be located away from flood hazard areas and, where relevant, areas that are prone to coastal inundation as a result of climate change. State planning policies provide the basis for land use planning, including settlements. For example, the SPPF floodplain management policy is to protect life, property and community infrastructure and also to protect areas of environmental significance and river health. This policy currently requires land affected by a 1-in-100-year flood to be identified in Planning Schemes maps and for planning decisions to avoid intensifying the impacts of flooding through inappropriately located uses and developments. This policy will be updated to reflect the 1% AEP flood (see Section 10.1) Local planning Planning Schemes contain a Local Planning Policy Framework that includes a Municipal Strategic Statement that explains an LGA s objectives and strategies in exercising land use controls in a planning scheme. Those controls include zones and overlays that regulate the use and development of land. The VPPs include one zone (urban floodway zone) and three overlays (floodway, special building and land subject to inundation overlays) directly relevant to flood-prone areas. In seeking to minimise or avoid the growth of future flood risks, the role of LGAs is to incorporate flood provisions into their Planning Schemes. The VPPs require LGAs to consider flood risks when preparing Planning Schemes (strategic planning), and in making land use planning decisions (statutory planning). Land use planning is an integral part of the optimum suite of flood mitigation measures for every floodprone area. Proposed Policy 13b LGAs with areas at risk of a 1% Annual Exceedance Probability flood must ensure that their Planning Scheme contains: the objectives and strategies for mitigating the risk in the Municipal Strategic Statement the appropriate zones and overlays. Proposed Accountability 13a LGAs are accountable for ensuring that their Planning Schemes correctly identify the areas at risk of a 1% Annual Exceedance Probability flood, and contain the appropriate objectives and strategies to guide decisions in exercising land use controls to do with flooding. LGAs are accountable for considering advice from CMAs as a Recommending Authority in assessing planning permit applications in areas identified at risk of a 1% Annual Exceedance Probability flood. LGAs are accountable to comply to recommendations and conditions from Melbourne Water as a Determining Authority in assessing planning permit applications in areas identified at risk of a 1% Annual Exceedance Probability flood. Proposed Action 13a DELWP, in consultation with local government, CMAs and Melbourne Water, will update the State Planning Policy Framework s floodplain management policy to use the 1% Annual Exceedance Probability flood as the terminology for the design flood event, replacing the current reference to the 1-in-100- year design flood event. DELWP in consultation with local government, CMAs and Melbourne Water will regularly review and if necessary revise the Victorian Planning Provision flood-related controls to ensure they remain applicable. CMAs and Melbourne Water will work with LGAs to ensure that planning schemes use the planning controls that correctly align with their flood risks. Revised Draft Victorian Floodplain Management Strategy 35

168 Part Planning for safe access during floods An accessway is the trafficable link, typically a public or private road, between a development on a floodplain and the land outside the 1% AEP flood extent. In some circumstances it is the flooding of accessways that limits land use options rather than flooding of the sites themselves. Under the VPPs, before issuing a planning permit for land covered by a flood overlay or Urban Floodway Zone, LGAs (with assistance from Melbourne Water and CMAs, as referral authorities) must consider: the frequency, duration, extent, depth and velocity of flooding of the site and accessway the danger to the occupants of the development, other floodplain residents and emergency personnel if the site or accessway is flooded. Australian Rainfall and Runoff (Project 10 Appropriate Safety Criteria for People) provides guidance on the flood velocities and depths that present a danger for children and adults. It also provides guidance on the depths at which small passenger cars are prone to float. Further guidance is needed if that information is to be applied consistently in CMA and Melbourne Water assessments of development proposals. The guiding principles affecting decision-making include: Accessways preferably should be flood-free. If this is not possible, egress during times of flood should not pose intolerable risks to occupants or to potential rescuers The number of occupants isolated during floods by the lack of accessways should not cause a material increase in the burden on emergency management agencies Raised accessways are not acceptable if they cause an increase in flood risk for third parties. It is important to work towards a broadly consistent application of these principles throughout Victoria. It is also important to develop a strategic approach to those situations where a proposed development is not located in a flood overlay or Urban Floodway Zone but its accessway is. At the moment there is no automatic trigger for such development applications to be referred to a CMA or Melbourne Water for flood advice. This could result in development occurring in inappropriate areas, or a purchaser of land not being aware of the accessway being flooded from time to time. The aim is to work towards an integrated approach to addressing flood risks at potential development sites and their accessways. Full disclosure of flood risks at these sites can be achieved in a number of ways. For example: LGAs should include in their Municipal Strategic Statements their objectives and strategies for mitigating flood risks, including the identification of priority areas for future flood investigations. Regional flood mapping and local flood studies should provide the basis for understanding flood behaviour for a range of events. Land use zones and overlays should be used, not just for identifying land affected by the 1% AEP flood, but also to control inappropriate development where accessways are cut by floodwaters. For example, an LGA may decide to retain flood free property as rural land rather than residential land if it has flood access issues. Or it may decide to raise an evacuation route. Emergency response plans should identify safe evacuation routes and provide an indication of the time required for safe evacuation (section 22). Flood disclosure information can be made available for larger events than the 1% AEP flood (section 21). This will enable a movement further away from case-by-case considerations. However guidance will still be required to assess development proposals in a consistent manner, taking into account the nature of the development and whether or not it would result in a material increase in total flood risk. Revised Draft Victorian Floodplain Management Strategy 36

169 Part 2 Proposed Policy 13c The need for safe accessways during floods will be considered in the preparation of strategic plans for future development, it will also be considered in Municipal Planning Schemes. Proposed Accountability 13b LGAs are accountable for developing strategic plans to address known flood risks, including the safety of accessways, in land use planning. DELWP, in consultation with the CMAs, Melbourne Water and VICSES, is accountable for developing and maintaining guidelines on the assessment of flood risks associated with accessways. The CMAs and Melbourne Water are accountable for providing advice to LGAs so that they can make decisions about the suitability of accessway arrangements for proposed developments. Bank failure from high flows damaging private roads. Source: North-East CMA Proposed Action 13b DELWP will prepare, for inclusion in the State Planning Policy Framework, guidelines on the assessment of flood risks associated with accessways to help inform local land use planning. Bairnsdale Caravan Park Source: East Gippsland CMA Revised Draft Victorian Floodplain Management Strategy 37

170 Part Existing planning coverage About 11.5% of Victoria s land mass is prone to a 1% AEP flood, fortunately not all at the same time. Figure 6 shows a map of the total 1% AEP flood extent for Victoria. It excludes storm-water flooding for Melbourne and other urban centres. Only about 2.5% of Victoria is urbanised, but urban areas are home to most of the population, with about 75% of Victorians living in Greater Melbourne. Only 5% of Victoria s urban areas is affected by 1% AEP flooding. While Victoria s flood databases indicate that 11.5% of the Victorian landmass is prone to a 1% AEP flood, the planning system records 7.5% of the landmass as being covered by Flood Overlays. This leaves 4% of the landmass without appropriate Planning Scheme Overlays. Melbourne Water and the CMAs currently provide important functions as floodplain management referral authorities, providing flood advice to LGAs under the Planning and Environment Act Those functions are linked to Section 202 of the Water Act, These functions are enabling rather than prescriptive, but they remain paramount to ensure that new land use and development proposals do not unduly add to past legacy flood problems, and that emergency management planning and response decisions take into account the flood risk. MILDURA 13.7 Streamlining land use planning Recommendation 86 of the Victorian Flood Review called for Victoria to adopt a strategy to expedite incorporation of updated flood mapping or modelling into planning schemes. As discussed in section 5, land use planning has not realised its potential in minimising or avoiding the growth in future flood risk. Until now, including flood overlays in Planning Schemes has depended on the capacity and willingness of LGAs for its implementation. Where that capacity and willingness has been deployed, land use planning is working well. Melbourne Water has made it possible for land use planning to work throughout metropolitan Melbourne. It also works well in regional areas that are subject to frequent flooding. However, there are large areas of rural and regional Victoria that remain inadequately covered. DELWP, the CMAs and Melbourne Water must help resolve this issue by collaborating with LGAs to overcome remaining capacity issues. They must also help to identify and use any potential economies of scale in the panel processes that are a necessary part of planning scheme amendments. The flood study process has evolved significantly to help address the capacity issues. For example, as explained in section 12.3, flood study outputs generally now include draft planning scheme amendments. 1% AEP flood extent SWAN HILL WODONGA SHEPPARTON WANGARATTA HORSHAM BENDIGO BALLARAT HAMILTON MELBOURNE BAIRNSDALE PORTLAND WARRNAMBOOL GEELONG TRARALGON Figure 6: Proportion of Victoria affected by 1% AEP floods based on currently available mapping Revised Draft Victorian Floodplain Management Strategy 38

171 Part 2 Digital elevation data, suitable for flood modelling, has been collected for all major floodplains in Victoria. Five catchment-scale pilot projects were completed to test a range of methodologies for producing regional flood studies. The pilot projects will inform catchment-scale flood mapping progressively under way for priority reaches in Victoria s major floodplains. Where appropriate the outputs from these studies will include draft planning scheme amendments. Proposed Policy 13d Regional floodplain management strategies will document and report on all urban and rural areas with known flood risks; they will also document and report on those townships that do not have planning controls to regulate any use or development within the 1% State Planning Policy Framework flood event. Proposed Action 13c The CMAs and Melbourne Water will develop implementation plans for their regional strategies that, as appropriate, will seek to either: help convert existing flood study data into planning scheme amendments; or conduct new flood studies to provide draft planning scheme amendments. DELWP will work with LGAs to streamline the processes involved in converting flood study outputs into appropriate municipal Planning Scheme amendments. DELWP will work with key stakeholders such as MAV to understand significant constraints of implementing appropriate municipal Planning Scheme amendments. Where an urban or rural area with identified flood risks has been provided with a draft planning scheme amendment, but is not adequately covered by appropriate planning controls and there are no processes in train to rectify that situation the issue may be escalated to the relevant Regional Emergency Response Planning Committee by any of the agencies involved in floodplain management or flood emergency management in the region. If that committee is unable to resolve the issue, it may then escalate to the Risk and Resilience Sub-committee of the State Crisis and Resilience Committee. This approach is in keeping with the importance placed on land use planning by the VFR The building system Building work in Victoria is controlled under the Building Act 1993 and the Building Regulations 2006 (the Regulations). One of the objectives of the Building Act is to protect the safety and health of people who use buildings. The Regulations adopt the Building Code of Australia (BCA) for the minimum technical standards for the construction of buildings. States and Territories have committed to support a nationally consistent BCA and to limit variations wherever practical. Certain developments require a planning permit and a building permit is required for the construction or significant alteration of most buildings in Victoria. Where the site for proposed building work is in an area liable to flooding and a planning permit is not required, a building permit applicant must obtain the report and consent of the LGA. Under this process, LGAs must consult with the relevant CMA or Melbourne Water. The Regulations define when land is in an area liable to flooding. Such areas can be determined from planning schemes or from descriptions on a certified or sealed plan of subdivision. They can also be otherwise designated by a LGA. On 1 May 2013, the Australian Building Codes Board introduced technical standards in the BCA for flood areas. These standards require certain new building work to be designed to resist structural damage during a flood, taking into consideration the expected velocity of floodwaters. It has not been practical to map velocities across all floodplain areas in Victoria. As part of a building permit application, the builder or designer must provide evidence to the relevant building surveyor that the building design complies with the BCA. Evidence must be based on advice on the flood level and water velocity of the site from the relevant CMA or a hydraulics engineer. Proposed Action 13d DELWP and the Victorian Building Authority will work together and continue to monitor the current system to improve the effectiveness of the flooding provisions of the Building Code Australia. Revised Draft Victorian Floodplain Management Strategy 39

172 Part 2 14 Planning for stormwater management in Melbourne and regional centres Urban stormwater flooding is a major issue for metropolitan Melbourne and urban areas across regional Victoria. In Melbourne, up to 130,000 properties are known to be at risk from flooding from the rivers, creeks and drains that are the responsibility of Melbourne Water. Eighty per cent of these are estimated to be at risk from the flooding caused by underground drains. Additional flood risks exist along LGA drainage systems not managed by Melbourne Water the number of properties at risk has not yet been determined for them. Urban stormwater flooding occurs in areas: developed before modern engineering drainage standards were introduced across Australia in the 1970s that allowed for overland flow along former valley lines in the urban landscape developed before appropriate planning controls were introduced to help manage exposure to flood risk affected by progressive infill development. The improved management of urban stormwater flooding is a central component of integrated water management. This represents a holistic approach to the management of all forms of water, including rainwater, stormwater, recycled wastewater and groundwater. It results in resilient urban water systems that deliver a range of social, environmental and economic benefits. Integrated water management brings together the community, LGAs, water corporations, catchment managers and land developers to help design Victoria s towns and cities with water in mind. Improved stormwater management will ensure that future impacts of a changing climate, population growth and new development will not reduce amenity or increase flooding. The cumulative effect of the stormwater management initiatives will help to reduce the risk of flooding in urban areas. In particular, rainwater and stormwater harvesting and a reduction in the connection of hard surfaces to drainage systems will reduce stormwater flows into streams in some rainfall events. Similarly, soil moisture retention strategies such as rain gardens, tree plantings and wetlands will contribute to a reduction in peak flows. It is important that new greenfield development, infill development and urban renewal areas are designed to mitigate property damage and other impacts associated with flooding. New developments must be planned and constructed to ensure they do not cause downstream flooding and avoid increases in the associated infrastructure or maintenance costs of managing flooding. This approach will be extended progressively to all urban areas across Victoria, using local community engagement effectively in each location. Where an area of intolerable stormwater flooding within a regional city has been identified in a regional floodplain management strategy, LGAs will engage with their local communities and evaluate treatm ent options to reduce risk. Proposed Policy 14a Integrated water management options will be used in developing and evaluating measures to manage the flood risks associated with stormwater in Melbourne and regional cities. Proposed Actions 14a Melbourne Water will: identify areas of stormwater flooding in Melbourne in the development of its Regional Floodplain Management Strategy assess and quantify different types (scales and frequencies) of stormwater flooding across Melbourne and refine the process for identifying and prioritising areas subject to intolerable flooding evaluate the treatment options discuss and seek agreement from beneficiaries for the treatment option that best manages the flood risk and provides other benefits. CMAs, in developing their regional floodplain management strategies, will work with LGAs to identify areas with a history of flash flooding in regional cities. Revised Draft Victorian Floodplain Management Strategy 40

173 Part 2 Increased density of development in urban areas can increase the proportion of impervious surfaces. That, in turn, increases the volume of surface run-off. Urban run-off needs to be managed to minimise the risk of flooding to third parties and to protect downstream waterways and environment. Clause 56 of the VPP requires new residential subdivisions to be designed to a standard that ensures flows downstream of the subdivision site are restricted to predevelopment levels unless otherwise approved where there are no downstream impacts. New sites are also required to comply with current storm water quality objectives. The VPP Practice Note (no. 39) provides guidance on meeting the integrated water management provisions required under clause 56 for residential subdivisions in an urban area. Flood retarding basins can provide significant flood mitigation benefits in urban areas. They are often used in new developments to comply with clause 56 requirements. Current design criteria for such structures require them to withstand a 1% AEP flood. Melbourne Water manages about 235 larger retarding basins, while local government authorities construct and operate them in regional areas. The design of retarding basins should consider broader community benefits including water resource, recreational and environmental benefits. Water captured in retarding basins can be reused if the reuse arrangements meet the design and management standards of the water authority or drainage authority. Proposed Accountability 14a LGAs are accountable for applying Victorian Planning Provision Clause 56 planning requirements to ensure that new developments do not have significant third party impacts as a result of increased runoff from impervious surfaces. 15 Planning around coastal flooding The Victorian Coastal Hazard Guide (2012) says coastal flooding:... may occur during extreme weather, when higher water levels cause seawater to flood land that is normally dry. The primary causes of inundation are storm surges combining with high tides (storm tides) and extreme wave events. Flooding can be worsened in estuaries by rainfall in coastal catchments. The Guide goes on to say: Additionally, the effects of climate change are contributing to a progressive permanent increase in sea level that will increase the extent and duration of storm-induced coastal inundation. This section focuses on what can be done to deal with coastal flooding The Interaction between coastal processes and coastal flooding It is difficult to separate coastal flooding from other coastal processes (shoreline erosion and recession) that modify landforms. For example, erosion and recession may be caused by flooding, wind action or wave action. Conversely, erosion can lead to the flooding of low-lying areas. The forthcoming edition of Australian Rainfall and Runoff will look at the interaction between coastal processes and severe weather events, including interaction between storm-induced flood peaks and peak ocean or peak estuarine conditions. Flood studies, and therefore flood models, need to consider the probabilities of these events occurring at the same time. This is similar to the inland situation where a flood study might have to deal with the probabilities of two or more streams, from different catchments, being in flood at the same time. Coasts and estuaries are dynamic and are influenced by processes such as tides and the effects of currents, winds, waves, rainfall and river flows. Where coastal processes are likely to adversely affect life, property or aspects of the natural environment, they create coastal hazards. Many issues surrounding coastal hazards are outside the scope of this Strategy. The Victorian Coastal Strategy 2014 (VCS) sets out policies and actions to respond to coastal hazards. This Strategy integrates with the VCS in those areas where flooding is identified as a priority coastal hazard. Revised Draft Victorian Floodplain Management Strategy 41

174 Part 2 The VCS identifies the continued need to help coastal communities understand and respond to the risks of coastal flooding. It intends to achieve this by: developing Regional Coastal Risk Assessments to strategically and consistently identify and prioritise coastal hazard management for key public assets including information about natural and built assets at risk of loss from erosion, and flooding, in Regional Coastal Plans and consider adaptation responses together these plans will provide a state wide perspective of coastal risk in Victoria analysing options for improved governance, regulatory and funding arrangements for the management of coastal Crown land (this will include cost sharing options for mitigation infrastructure on Crown land) supporting collaboration across agencies and communities to enable effective adaptation planning Identifying risks at the regional level The Victorian Government s Future Coasts program developed tools to help understand coastal risks under existing climatic conditions, and future scenarios. These tools included high-resolution coastal digital elevation models, coastal flood mapping, the Coastal Hazard Guide, the Coastal Asset Information Library, and four pilot local coastal hazard assessments. Future Coasts coastal flood mapping will soon be uploaded to the Victorian Flood Database. This mapping is fit-for-purpose for strategic planning at the regional scale; it identifies areas that may be affected by flooding in the future so that they can be prioritised for further assessment. Those parts of DELWP responsible for coastal management will continue to work with Victoria s Regional Coastal Boards to prepare Regional Coastal Plans that will establish these priorities. Those plans will lead to implementation actions to address the priorities as funding becomes available. DELWP is also preparing regional coastal hazard assessments to address risks to key state coastal assets. Proposed Action 15a DELWP will: develop regional coastal risk assessments to strategically and consistently identify and prioritise coastal hazards and manage risks to key public assets support the completion of Regional Coastal Plans to inform coastal adaptation planning in ways that will, among other things, identify priority areas of coastal land at risk from flooding. Councils can develop adaptation plans to strategically assess and manage coastal hazards (like erosion and flooding). Such plans: involve the community guide Planning Schemes including updating what areas are appropriate or not appropriate for development assess options for managing inundation generate a better understanding of the issues to be faced now and in the future. Where adaptation plans indicate that flood mitigation infrastructure is required for public benefit then, in line with government policy, LGAs will contribute to the capital costs in cost-sharing arrangements with the Victorian and Australian Governments. There is a need to clarify the funding arrangements for flood mitigation infrastructure on the coast. This Strategy supports the VCS action to analyse options for improved funding arrangements for the management of coastal Crown land. (This will include options for funding arrangement for the ongoing management and maintenance of flood mitigation infrastructure on Crown land.) Cost-benefit-analysis will determine the priority surrounding government contributions. The total costs used in those assessments will include the costs of third-party impacts, such as reduced sand replenishment on other beaches. Adaptation plans need to be regularly updated in the light of new data, new knowledge and emerging risks. Revised Draft Victorian Floodplain Management Strategy 42

175 Part Supporting adaptation responses Adapting to a changing climate involves reducing risks, increasing resilience and taking advantage of opportunities. Everyone in coastal communities needs to play a part in adapting to coastal change in this way. LGAs and land managers need to make wise land use decisions, which balance current use and development opportunities with longer term use and sustainability of the coast. The Victorian Climate Change Adaptation Plan sets out the government s priorities to build Victoria s climate resilience. It provides a framework for adaptation planning across the Victorian Government. The government is working closely with LGAs to produce local coastal adaptation responses. The outcomes of four pilot local coastal hazard assessment projects (in Port Fairy, the Bellarine Peninsula, Western Port and the Gippsland Lakes), and related adaptation projects, will be used to guide the practical application of adaptation principles. Proposed Policy 15a LGAs wishing to strengthen their community s capacity to adapt to the effects of coastal flooding will be supported. Proposed Action 15b DELWP will: work with LGAs to develop adaption responses from the hazard assessment pilot projects identify other areas where this process can be used. LGAs can develop adaptation plans to strategically assess and manage coastal hazards (like erosion and flooding). Such plans: involve the community generate a better understanding of the issues to be faced now and in the future assess options for managing flooding guide Planning Schemes including updating what areas are appropriate or not appropriate for development. Where adaptation plans indicate that flood mitigation infrastructure is required for public benefit then LGAs will contribute to the capital costs in cost-sharing arrangements with the Victorian and Australian Governments. This Strategy supports the VCS action to analyse options for improved funding arrangements for the management of coastal Crown land. (This will include options for funding arrangement for the ongoing management and maintenance of flood mitigation infrastructure on Crown land.) Cost-benefit-analysis will determine the priority surrounding government contributions. The total costs used in those assessments will take account of the range of social, environmental and economic values associated with the coast, such as the value of beaches and the costs if they are not able to be used by the community. Adaptation plans need to be regularly updated in the light of new data, new knowledge and emerging risks Planning for rising sea levels While the CMAs and Melbourne Water have worked to assess the effects of inundation from the sea on coastal development, they do not have the resources to hold primary responsibility for assessing the effects of coastal hazards on coastal development. There needs to be clear demarcation between coastal flooding issues and broader coastal hazard assessments. As outlined in section 13, the CMAs and Melbourne Water will work in active partnerships with LGAs to develop regional priorities for riverine and estuarine floodplain management. For coastal flooding, however, the CMAs and Melbourne Water will have a supporting role; LGAs wishing to prepare adaptation plans, conduct flood studies or amend Planning Schemes in response to the risk of coastal flooding can seek assistance from DELWP and the CMAs or Melbourne Water. Where LGAs amend their Planning Schemes to show land subject to inundation caused by seawater, the CMAs and Melbourne Water will act as referral authorities for recommendations on land use planning. Revised Draft Victorian Floodplain Management Strategy 43

176 Part 2 The State Planning Policy Framework (SPPF) documents strategies to plan for and manage the potential coastal impacts of climate change in the following terms: In planning for possible sea level rise, an increase of 0.2 metres over current [1% AEP] flood levels by 2040 may be used for new development in close proximity to existing development (urban infill). Plan for possible sea level rise of 0.8 metres by 2100, and allow for the combined effects of tides, storm surges, coastal processes and local conditions such as topography and geology when assessing risks and coastal impacts associated with climate change. For new greenfield development outside of town boundaries, plan for not less than 0.8 metre sea level rise by The VCS reaffirms that the current planning benchmarks for sea level rise are being retained, and will be reviewed and updated, if necessary, as part of the next iteration of the VCS. DELWP and Melbourne Water have both produced guidelines to ensure that the SPPF strategies can be applied to Municipal Planning Schemes using clear and consistent principles. Those guidelines allow for the application of the planning benchmarks at the regional and local levels. For example, with regard to the potential rise of 0.2 metres, planning controls should include an additional freeboard allowance of at least 0.2 m on top of existing freeboard requirements (unless 0.2 m has been added to the 1% AEP flood levels). The aim is to provide flexibility for coastal communities to remain viable by enabling appropriate infill development over the next few decades, with future adjustments made as certainty on degree of sea level rise increases. Adaptation planning is seen as the medium to long-term solution to managing the impacts of higher sea levels. By contrast, if the intention is to transform land use from rural to urban purposes, longer-term planning controls should be used and the proposal should be assessed against long-term risks from projected sea level rise of not less than 0.8m by In providing advice to LGAs, the CMAs and Melbourne Water have discretion to recommend more or less stringent freeboard requirements in some circumstances. For example, they might do so if the proposal were to result in a small increase in flood risk relative to existing risks (e.g. small building extensions). Similarly, they might waive the requirements where flood damage was seen as an acceptable business risk this might apply to some industrial and commercial land uses. Proposed Accountability 15a DELWP and Melbourne Water are accountable for maintaining guidelines on how to apply those clauses of the State Planning Policy Framework that relate to projected rises in sea level. DELWP s guidelines for dealing with sea level rise apply unless an LGA s adaptation plan makes specific alternative arrangements. Adaptation plans will provide the medium through which communities can plan for the complexities of coastal change both for infill development in urban zoned land within established settlements and for a change from rural to urban land uses. Revised Draft Victorian Floodplain Management Strategy 44

177 Part 3: Reducing existing risks Levee breached at Benjeroop, January Source: North Central CMA Revised Draft Victorian Floodplain Management Strategy 45

178 Part 3 16 Flood warnings A specific flood is only manageable if real-time assessments can be made about its behaviour and its consequences. Armed with such assessments, it is possible to coordinate appropriate responses, and advise and educate communities. Flood warnings can help local communities mitigate flood damage. Effective flood warnings provide communities, and emergency management agencies, with information about when flooding may occur, its likely severity and what to do to reduce damages An overview of the future arrangements The Bureau of Meteorology (BoM) will develop new flood prediction services using a costrecovery model that involves DELWP covering the capital costs of initial model development and BoM covering the cost of operating, maintaining and continually improving those models. Existing flood prediction services will continue to be operated, maintained and continually improved by BoM. Where a flood study identifies the need for new stream monitoring gauges to support a TFWS for a local community within Melbourne Water s region, Melbourne Water will cover the capital and maintenance costs of those gauges. Where a flood study or a regional floodplain management strategy outside Melbourne Water s region, identifies the need for a TFWS service and that service is supported by the community, the capital costs new stream monitoring gauges will be shared between the Victorian and Australian Governments. The local community, through their LGA, will fund the ongoing maintenance costs for gauges associated with flood warning services. Where existing stream monitoring gauges are providing flood warning services, the Victorian Government expects existing cost sharing arrangements to continue until a regional floodplain management strategy, or a local flood study, assesses the need for a TFWS service. Where existing gauges are assessed as being an essential component of a TFWS, the costs of maintaining those gauges will be shared to the extent that they reflect benefits to LGAs for flood warning, to CMAs for water quality monitoring and water corporations for water resource assessments Flood warning services for all Victorians All Victorian communities receive weather-related warnings such as Flood Watches and Severe Weather Warnings delivered by the BoM. These services provide advice on weather conditions that have the potential for heavy rainfall and flooding. The BoM s website also provides near real-time river height data and rainfall data, for most major rivers at risk of flooding. This information allows people to use their own local knowledge to assess their local impacts, and take appropriate action. All communities receive general safety messages, such as do not drive, walk or ride through floodwaters from VICSES. Everyone also has access to guidance on appropriate flood responses. For example, VICSES issues FloodSafe guides to help local communities prepare for and respond to floods. Communities with high potential for flood damage receive more sophisticated flood warning services. These can include local predictions about the rise and fall of floodwaters, details on the roads and properties likely to be inundated, and local advice about how to prepare for and respond to predicted floods. Regional floodplain management strategies and local flood studies may identify additional communities where more sophisticated services are warranted. The ongoing review of regional floodplain management strategies will enable continual assessment of flood warning services to communities. Sandbagging at Dimboola during the 1956 flood. Source: David Livingston Revised Draft Victorian Floodplain Management Strategy 46

179 ... / 200ar i hor s ham pr of WI THOUT. dg J an. 16, : 18: 42 Flood Bulletin Part The Total Flood Warning System concept Total Flood Warning Systems (TFWSs) encompass all the elements needed to maximise the effectiveness of the community s and the emergency management agencies response to floods. Each element of the TFWS (Figure 7) plays a part in the effectiveness of flood warnings; each helps to reduce damage to property and threats to life. Victoria s TFWSs are designed and implemented in the context of the national flood warning arrangements outlined in section 7. Each locally specific TFWS will be designed and implemented in accordance with the relevant regional floodplain management strategy (section 12) or local flood study (section 12.3). The TFWS service requires the combined efforts of a number of agencies to deliver effectively for communities. The TFWS concept is explained in the Australian Emergency Management Manual Series, Manual 21 Flood Warning Assessing Total Flood Warning System service at state, regional and local levels The floods exposed serious deficiencies with the management of TFWS services; no one agency had overall accountability for the coordination of, or performance reporting on, TFWS services at the state level. To rectify this, the Victorian Government has made DELWP accountable for the coordination of TFWS services at the state level. It is also accountable for documenting a state-level TFWS service development plan. DELWP will do this in consultation with VICSES, BoM, Melbourne Water, CMAs, LGAs, water corporations and other stakeholders as required. The TFWS service development plan will be informed by the rolling three-year implementation plans coming out of the regional floodplain management strategies. In preparing those regional strategies, the CMAs and Melbourne Water will systematically assess the existing TFWS services provided to the flood-prone communities in their region, using the state-wide assessment framework currently being developed by DELWP. They will also assess the TFWS service needs of each flood-prone community. Review Data Collection Network: Regional Water Monitoring Partnerships Flood height prediction: Bureau of Meteorology and Melbourne Water 5 Response and community education: VICSES Interpretation Flood mapping: CMAs/ Melbourne Water and LGA 4 Warnings: VICSES and Bureau of Meteorology Community Flood Bulletin Community Figure 7: The elements of a Total Flood Warning System Revised Draft Victorian Floodplain Management Strategy 47

180 Part Matching Total Flood Warning System services with community needs Once the CMAs and Melbourne Water have completed their assessments of existing TFWS services and future TFWS needs, they will identify those TFWSs that need to be modified. DELWP will then prioritise these TFWS service needs at the state level. They will also clarify the accountabilities for each TFWS element with all the agencies involved. In general terms, the roles and responsibilities in operating and maintaining the overall service can be summarised as follows: Data collection network infrastructure: Across Victoria, there are some 780 active river level and rainfall gauges maintained through the relevant Regional Water Monitoring Partnership. The partnerships involve DELWP, LGAs, CMAs or Melbourne Water, and other water corporations with an interest in the use of gauge data. The partnership approach allows data to be collected to a well-defined standard once, but used for multiple business needs, such as allocation management, compliance monitoring, flood warning, water resource assessment and river health management. DELWP manages the Regional Water Monitoring Partnership contracts and Melbourne Water manages equivalent contracts within the Port Phillip and Westernport region. Of these 780 active gauges, 237 are used in the delivery of flood warning services. About 180 of the gauges used in flood warning are also used by CMAs and Water Corporations for other purposes (such as environmental flows, bulk entitlements and infrastructure operations). The multiple uses of gauges enable the operational costs to be minimised and shared between partner organisations. Flood prediction service maintenance: BoM (outside the Port Phillip and Westernport region) or Melbourne Water (within the Port Phillip and Westernport region) maintains and funds the prediction services for the locations defined in the BoM Service Level Specification for Flood Forecasting and Warning Services. Maintenance includes continually improving prediction techniques. Interpretation (flood mapping): Local flood studies produce updated flood mapping. DELWP includes updated flood mapping and flood behaviour information in the flood intelligence platform. Message construction and dissemination: BoM and Melbourne Water maintain appropriate flood warning messages and associated dissemination channels for locations noted in the BoM Service Level Specification. VICSES maintains its dissemination channels for flood bulletins. VICSES will develop appropriate flood bulletin messages using available flood behaviour and intelligence material. DELWP maintains the flood intelligence platform to enable access to appropriate information for messages and bulletins. LGAs use locally specific dissemination systems to support VICSES services. Flood response planning and community awareness: VICSES maintains flood response plans and community education material. CMAs and Melbourne Water supply VICSES with any significant updates of the flood mapping and flood behaviour information. Proposed Policy 16a Each of Victoria s Total Flood Warning Systems will depend on active cooperation and collaboration between DELWP, BoM, VICSES, the relevant LGA and the relevant CMA or Melbourne Water. Case study: Smarter flood gauges for Strathbogie Strathbogie Shire, which takes in the townships of Violet Town and Euroa, experienced widespread flooding in September In the aftermath, the Victorian Government provided $260,000 to upgrade 14 flood warning gauges for the Shire. Renovating ageing equipment with more modern technology provides greater assurance that the gauges will perform well in future floods. The renovated flood warning gauges are an integral element in the TFWS services delivered to the Shire s communities. Strathbogie Shire will contribute to the maintenance and operational costs of those gauges as a member of the Northern Water Monitoring Partnership. Members of the public can view information from Victoria s network of flood monitoring gauges at The TFWS service requires the combined efforts of a number of agencies to deliver effectively for communities. Revised Draft Victorian Floodplain Management Strategy 48

181 Part 3 Proposed Accountability 16a DELWP will coordinate the inputs necessary to continually strengthen agencies co-operation and collaboration and will report any problems to the Inspector General for Emergency Management. DELWP is accountable for maintaining and continually improving the framework for assessing existing Total Flood Warning Service services in the context of the relevant community s identified flood risks. Melbourne Water and the CMAs are accountable, through their regional floodplain management strategies, in consultation with relevant communities, councils, VICSES and BoM, for coordinating the assessment of existing Total Flood Warning Service services, and the design and implementation of fit-forpurpose Total Flood Warning Service services that align with the identified flood risks faced by flood-prone communities in their regions. VICSES is accountable for making sure that local knowledge is incorporated into response planning and community education as part of the Total Flood Warning Service services. DELWP is accountable for developing, maintaining and continually improving systems and procedures to provide assurance that all Victoria s Total Flood Warning Service services are being maintained in a state of operational readiness. DELWP is accountable for documenting a state-level Total Flood Warning Service service development plan. DELWP will do this in consultation with VICSES, BoM, Melbourne Water, CMAs, LGAs, water corporations and other stakeholders as required. Melbourne Water and the CMAs, in consultation with relevant communities, councils, VICSES and BoM, are accountable for determining appropriate flood class levels (minor, moderate and major) for flood-prone communities. DELWP is accountable for co-ordinating revisions of flood class levels with relevant agencies. Proposed Action 16a DELWP will: establish a framework to assess Total Flood Warning Service services in the context of the relevant community s identified flood risks. prepare a rolling three-year State Total Flood Warning Service development plan informed by the implementation plans coming out of regional floodplain management strategies and the outputs of local flood studies. Temporary levee to protect road infrastructure at Bells Swamp near Bendigo. Source: DELWP Revised Draft Victorian Floodplain Management Strategy 49

182 16.6 Review The Inspector General for Emergency Management has developed an assurance regime to meet its obligation to develop an audit framework for the Total Flood Warning Service. The assurance regime includes: a mapping process to describe the Total Flood Warning Service a framework to facilitate the collection of consistent, relevant and quantifiable information or data to support rigorous monitoring and assessment of the performance of the Total Flood Warning Service a three-year schedule of assurance activities, including proactive and reactive reviews to test all aspects of the Total Flood Warning Service. As well as the proactive reviews undertaken as part of the regional floodplain management strategies, DELWP will monitor and review how each Total Flood Warning Service performs when it is needed. Each Total Flood Warning Service will, as a matter of course, be reviewed after a major flood. Proposed Policy 16b Local Total Flood Warning Systems are operationally reviewed after each flood involving the establishment of an incident control centre. Proposed Accountability 16b The relevant CMA or Melbourne Water is accountable, after each flood involving the establishment of an incident control centre, for convening a meeting of all agencies accountable for providing input to the relevant Total Flood Warning System to review the operation of the Total Flood Warning System during the incident and to determine whether a more detailed review of the system is required. The Inspector General for Emergency Management is accountable for establishment of a Total Flood Warning Service assurance regime and the conduct of the systematic assurance reviews. Part Working towards flash flood warning services Flash floods can pose a potential threat to life and property in some urban locations. Regional floodplain management strategies will identify locations where there is a history of flash flooding. Flash flood warnings require expedited warning processes. They are unlike the TFWSs for riverine flooding; those are based around having at least six hours to collect data, run prediction models, interpret flood mapping, determine potential consequences, and construct and disseminate warnings. Given the short timeframes associated with flash flooding more certainty is needed about each agency s roles, capacities, responsibilities and accountabilities, and the community s capacity to respond appropriately. Proposed Policy 16c The CMAs and Melbourne Water, with the support of VICSES and LGAs, will identify areas with a history of flash flooding and include them in their regional floodplain management strategies. Proposed Action 16b DELWP will work with the Emergency Management Commissioner to evaluate the potential to disseminate generalised district-scale flash flood warning services based around BoM s existing severe weather warning services, using similar dissemination approaches employed for bush fire. DELWP will work with BoM, the Emergency Management Commissioner and VICSES to evaluate the potential to provide localised neighbourhood-scale flash flood warning services where there is a history of flash flooding. Revised Draft Victorian Floodplain Management Strategy 50

183 17 Flood mitigation infrastructure There are a number of common structural measures used to mitigate flooding including levees, channel modifications, bypass floodways, retention basins, dams and floodgates. This section considers those measures whose primary objective is to protect against flooding. In the greater Melbourne region, Melbourne Water is responsible for flood mitigation in drainage catchments greater than 60 hectares, and LGAs manage flood mitigation in drainage catchments of less than 60 hectares. Melbourne Water identifies flood extents, controls development in floodplains, provides advice on flooding to LGAs and provides flood warnings to the community. It also develops flood mitigation plans and where necessary builds, manages and maintains flood mitigation infrastructure in the Port Phillip and Westernport region. This Strategy does not propose changes to the existing arrangements for floodplain management in Melbourne. However, this does not preclude changes being made to them in the future as a result of government endorsement of its regional floodplain management strategy. Circumstances in regional Victoria, however are quite different. The floods revealed serious deficiencies in the management arrangements for flood mitigation infrastructure outside Melbourne. Responsibilities were either non-existent or blurred between CMAs and LGAs, and accountabilities were not assigned consistently across the state. Notwithstanding those problems, a number of LGAs and their communities, have been proactive in leading activities to reduce flood risk. The benefits of well-maintained flood mitigation infrastructure were demonstrated in the floods. Levees had been constructed in the towns of Kerang and Nathalia in response to previous large floods and, importantly, those levees had been regularly maintained. As a result, both towns were spared extensive flood damage. Lessons from these floods have led both LGAs to take measures to reinforce their flood defences. Part 3 In recognition of public benefits of these levees, the State and Australian Governments shared the construction costs with those LGAs and the LGAs took responsibility for ongoing maintenance. This approach has been applied successfully since the floods, for example in Creswick (see case study, page 52). Unfortunately, such arrangements have not been applied consistently across the state. There are a number of fundamental problems inherent in the current arrangements including: Uncertainty that mitigation infrastructure would perform to its design standards in a flood (if indeed that standard is known) The benefits of the mitigation works are not well understood and those benefits do not necessarily match expectations Emergency response agencies often lack sufficient information on levee standards to allow them to predict whether or not a levee is likely to fail, and so they cannot factor this consideration into their flood bulletins Concerns that downstream flood impacts are worsening as a result of floodwaters being channelled by upstream levees Insurers are assuming, in the absence of reliable information, that flood mitigation infrastructure is not in place because it is not owned or maintained and therefore premiums are unduly higher than appropriate. The Victorian Government is determined to remove that uncertainty and inconsistency in management. It wants to instil robustness into the framework for managing flood mitigation infrastructure. This work is complex and will require a number of steps before formal management arrangements will be in place. The government is determined that the lessons and management arrangements in place for Kerang and Nathalia should be seen as best practice and that this approach of cost sharing between governments and local communities will be adopted for regional urban flood mitigation infrastructure. To that end, the relevant accountability arrangements and policy settings for the future are summarised below. The practical implications associated with implementing these policies are outlined in sections 17.2, 17.3, 17.4 and Revised Draft Victorian Floodplain Management Strategy 51

184 Part An overview of the future arrangements The management arrangements proposed for future flood mitigation are summarised as: New and existing regional urban flood mitigation infrastructure, where it is demonstrated to be cost-effective, will be formally maintained and managed by LGAs. The cost of construction work, or initial restoration work necessary to bring it back to an acceptable standard, will be shared equally between the LGA, and the Victorian and Australian Governments. LGAs will be accountable for ongoing maintenance (sections 17.2 and 17.3). Where existing rural infrastructure has been constructed by government, if it is found to provide a clear public benefit, in terms of protecting life and property, and it is demonstrated to be cost-effective, then LGAs and the Victorian and Australian Governments may contribute to a capital upgrade of the infrastructure, provided there are ongoing local arrangements in place to maintain it to an agreed standard (section 17.4). New and existing levees on private land that provide private benefits would be constructed and maintained by the landholder. The landholder will still be required to consider third party impacts as part of any approvals necessary to undertake works (section 17.5). Individuals prepared to pay for the maintenance of flood mitigation infrastructure on Crown land can seek a permit from CMAs or Melbourne Water to maintain it. Levees on Crown land cannot be increased in height or length (section ). Case study: Establishing flood mitigation infrastructure in Creswick Creswick, at the confluence of Creswick and Slatey Creeks, was flooded four times between September 2010 and February The flooding was extensive in September 2010 and January In February 2011, the Victorian Government moved to help the local community develop and implement a flood mitigation plan. Funding was made available to clear creek blockages and to increase the town s resilience to flooding. Hepburn Shire Council and North Central CMA worked together and consulted extensively with the Creswick community to capture the local understanding of the floods impacts on the town. Local knowledge was combined with technical information, and works were designed to ensure that if a flood the size of January 2011 hit the town again the impacts would be much lower. Taking advantage of funding available through the Victorian Government s FloodZoom initiative and the Australian Government s Natural Disaster Resilience Grants Scheme, Hepburn Shire Council started implementing the flood mitigation plan in Levee bank and creek works were started that year. Hepburn Shire Council, the Victorian Government and the Australian Government shared the total capital costs of $650,000. The last stage of implementation of the plan will be carried out in 2015, with VicRoads providing design and construction services to replace two road crossings on the creek. The total capital costs of $800,000 will again be shared between the Shire and the Victorian Government. A recently constructed earth levee blends into the landscape of this riverside park in Creswick. Source: Simone Wilkinson Levees can take different forms this wall is designed to fit along a narrow strip of public land, and to look appealing for overlooking properties. Source: Simone Wilkinson Revised Draft Victorian Floodplain Management Strategy 52

185 Part 3 Proposed Policies 17a Melbourne Water can, through its regional floodplain management strategy, propose changes to the existing accountabilities for flood mitigation infrastructure within the Port Philip and Westernport Region. All future large-scale flood mitigation infrastructure outside Melbourne Water s region will be implemented as Water Management Schemes under the Water Act 1989 unless there are demonstrated benefits associated with alternative formal arrangements (section 17.2). Flood mitigation infrastructure outside Melbourne Water s region that is not currently subject to formal management arrangements will remain that way unless the relevant LGA determines that the infrastructure should be brought into formal management arrangements (section 17.3). Where an LGA outside Melbourne Water s region determines, in consultation with its local community, that existing large-scale flood mitigation infrastructure is necessary to reduce existing flood risks, that infrastructure will be brought into formal management arrangements and implemented as Water Management Schemes unless there are demonstrated benefits associated with alternative formal arrangements (section 17.3). The Victorian Government s expectation is that the costs of designing and building future largescale flood mitigation infrastructure for regional urban areas will be shared equally between the Victorian and Australian Governments, and the relevant LGAs (section ). The Victorian Government s expectation is that the costs of restoring or upgrading existing large-scale flood mitigation infrastructure to bring it into formal management arrangements will, for regional urban areas, be shared equally between the Australian Government, the Victorian Government and the relevant LGAs (section ). Proposed Policies 17a cont. The maintenance and management of all flood mitigation infrastructure accepted as a Water Management Scheme by the Minister for Water will be funded by beneficiaries (through relevant LGAs) and will be subject to third-party auditing arrangements to ensure it continues to be maintained (section ). If no formal arrangements are put in place for a levee that is on Crown land and a local beneficiary sees benefit in that levee, they may apply to maintain it themselves at their own costs via a Levee Maintenance Permit issued by a CMA or Melbourne Water (section 17.4) It will be the responsibility of private landholders to maintain levees on private land that are not managed by LGAs or under Water Management Schemes (section ). Proposed Accountability 17a Within Melbourne Water s region, the accountabilities for flood mitigation infrastructure will remain with their current management agencies: LGAs are accountable for mitigating flood risks within drainage catchments of less than 60 hectares. Melbourne Water is accountable for mitigating flood risks within drainage catchments greater than 60 hectares. In some rural catchments, LGAs are accountable for mitigating flood risks within drainage catchments of less than 200 hectares and Melbourne Water is accountable for mitigating flood risks within drainage catchments greater than 200 hectares. Outside Melbourne Water s region, relevant LGAs are accountable for: leading the processes to determine and implement, through flood studies and Water Management Schemes, the flood mitigation infrastructure necessary to meet the needs of their communities, taking into account economic, social, cultural and environmental issues the ongoing maintenance and management of infrastructure that is determined necessary to reduce flood risks for their communities. Revised Draft Victorian Floodplain Management Strategy 53

186 Part Establishing new flood mitigation infrastructure The regional floodplain management strategies outlined in section 12 will identify areas where flood mitigation infrastructure is a priority for investigation. The starting point is a flood study (as described in section 12.3). A key output of any flood study will be consideration of the options for flood mitigation infrastructure. It is open to Melbourne Water, the relevant LGA or a CMA to initiate a flood study either individually or jointly. When an LGA takes the initiative, Melbourne Water and the CMAs are expected to provide technical support. Flood study priorities will be outlined in regional floodplain management strategy or in reviews of flood events Establishing Water Management Schemes The Victorian Government prefers that large-scale flood mitigation infrastructure be designed and implemented as Water Management Schemes under the Water Act The Water Management Scheme process sets out clear steps for information gathering, community engagement (including gaining consensus), and final determinations. It also reduces liability exposure for LGAs. Proposed changes to Victoria s water legislation would bring LGAs under the same liability regime as water corporations for damage caused by the flow of water from their stormwater infrastructure and from infrastructure identified in a LGA Water Management Scheme. Under this regime they would be liable to pay compensation if the flow of water were caused by intentional or negligent conduct. An LGA s financial resources, its compliance with applicable general standards and the state of scientific knowledge of local conditions would be taken into account in determining whether or not its conduct was negligent. Community engagement is vital to the successful implementation of flood mitigation infrastructure. Communities must be consulted to allow their concerns, their local knowledge and their ideas about management options to be considered. In floodplain management, there are always trade-offs between benefits for the community as a whole and the costs associated with reducing risk. It is important that management options are carefully thought through, supported by technical information and that any potential third party impacts are considered and appropriately managed. Water Management Scheme processes include extensive community consultation on the design and construction of flood mitigation infrastructure. The process can be demanding and in the interests of timeliness, should be begun in parallel with the commissioning of the associated flood study. Proposed Accountability 17b DELWP is accountable for providing assistance to LGAs and other authorities to help them develop and implement Water Management Schemes The management framework for flood mitigation infrastructure Few LGAs have extensive experience in designing and managing flood mitigation infrastructure. It is important for DELWP to provide guidance on seeking the relevant skills and expertise for the design, construction and management of such infrastructure. Proposed Accountability 17c DELWP is accountable for maintaining a management framework for flood mitigation infrastructure. Proposed Action 17a DELWP will develop and maintain management guidelines that provide: guidance on the location of flood mitigation infrastructure (as outlined in the Victorian Waterway Management Strategy (2013), when flood studies consider new levees, they should, as far as practicable, be located to minimise the impacts of high-energy flows) guidance on developing levee management and maintenance arrangements guidance on inspection and auditing requirements and provision for third party inspections information and guidance on the use of temporary and demountable levees. Revised Draft Victorian Floodplain Management Strategy 54

187 Part 3 DELWP s guidelines will not be prescriptive. It is important to allow scope for innovation and continual improvement in the development of cost-effective flood defences. The guidelines will mainly be concerned with assurance that those defences will be adequately maintained. Floodprone communities, through their LGAs, will be free to choose the design flood event for those defences; this may be for floods more frequent than the 1% AEP flood event used for land use planning. Information will be available to property buyers so they aware of the level of protection the infrastructure will provide Cost-sharing arrangements The Victorian Government s expectation is that the costs to prepare and implement Water Management Schemes specifically excluding ongoing management, maintenance and auditing costs will, on a priority basis, be shared equally between the Australian Government, the Victorian Government and the relevant LGA. Government contributions to the capital costs of large-scale flood mitigation infrastructure to protect urban areas will be contingent on the local beneficiaries, through their LGA, being committed to meeting the ongoing management, maintenance and auditing costs. The benefits of avoiding disruption to the functioning of urban areas often extend throughout the region s economy. Flood mitigation infrastructure intended primarily to benefit urban areas may also deliver benefits to rural areas. For these reasons, it is appropriate that LGAs raise the necessary revenue across its municipality. The Victorian Government will work with local government to determine further guidance on cost sharing arrangements if required Planning controls behind formally managed levees Even if there is no overtopping, the lowestlying areas behind levees will still be subject to stormwater flooding especially if there is a breakdown in the drainage and pumping systems designed to keep those areas dry. LGAs are responsible for ensuring that their Planning Schemes help to minimise or avoid increased risk of flooding in the lowest-lying parts of those areas protected by levees. Proposed Accountability 17d LGAs are accountable for ensuring that appropriate planning controls remain in place for areas behind levees that have not been designed to protect these areas against a 1% AEP flood, and for the consideration of additional contingency measures to manage residual risk for new urban developments behind levees designed for 1% AEP flood. LGAs are accountable for mitigating the risks of inundation in the low-lying parts of those areas protected from riverine flooding by formally managed levees Management arrangements for levees in rural areas New regional urban levee systems to protect existing properties can sometimes be justified on benefitcost grounds. By contrast, building new, large-scale rural levee systems is generally no longer considered to be best practice because they reduce flood storage, increase flood levels and increase erosion potential within waterways. Nonetheless, there may be limited circumstances in which new rural levee systems may be considered. For example, they might be necessary for environmental watering or to reduce the risk of avulsions. Therefore, the government will not explicitly rule out the construction of new rural levee systems. Any such levee system would need to be fully evaluated through a flood study that took full account of the associated social, cultural, economic and environmental costs and benefits. The government will not fund construction of new rural levee systems, or repair flood damage to existing rural levee systems, that primarily provide private benefits. An alternative way to reduce existing flood risks in rural areas is to allow landholders to build ring levees to protect individual buildings and curtilages (the enclosed area of land adjacent to a building or dwelling). These are often small enough not to have significant third party or environmental impacts. However, individual levee protection should not be a substitute for setting floor levels above the 1% AEP flood level for new dwellings. Revised Draft Victorian Floodplain Management Strategy 55

188 Proposed Policy 17b Third party impacts will continue to be considered in the planning scheme approval processes associated with the construction and maintenance of private levees on private land. Levees on Crown land that are not being formally managed will be allowed to weather away unless those benefiting from them decide to repair and maintain the levee (or part of the levee) under a permit issued by a CMA (section 17.4) Essential service providers Essential services include roads, bridges, dams, weirs, channels, drains, telecommunication facilities, power facilities and water treatment plants. They are owned and operated by a variety of organisations. Where the installation of new, or the maintenance of existing, essential-service infrastructure has the potential to affect flood behaviour, the Victorian Government encourages collaboration between essential-service infrastructure providers, LGAs and CMAs. The Government also encourages collaboration where new or updated essential-service infrastructure has the potential to provide flood mitigation benefits. This has been achieved at the Western Freeway bypass of Ballarat, for example, where flood-retarding basins have been incorporated into the freeway embankment, reducing the potential for flooding in the Ballarat urban area Bringing existing regional urban infrastructure into formal management arrangements The floods of revealed serious deficiencies in the management arrangements for flood mitigation infrastructure outside Melbourne. The Government s response to the ENRC inquiry provides clear policy settings for the ongoing management of Victoria s existing flood mitigation infrastructure. This means, for example, that if the existing regional urban levees are to be managed into the future, they will need to be brought under formal management arrangements. Under these arrangements, they will be owned, managed and maintained by LGAs through Water Management Schemes under the Water Act Part Context It is important to bring this requirement into perspective. Of the levees in regional Victoria 2 : About half the regional urban levees, across a number of municipalities, are already being formally managed. About 3,000 km are rural levees on private land and will be privately managed. About 900 km are rural levees on Crown land and are not currently being maintained. It is likely that most of them will never be formally maintained because the costs of restoring them to a reasonable standard and maintaining them formally will be greater than the benefits. If this is not the case, there will still need to be support from the community and a rating mechanism established by an LGA to have them formally maintained. Private beneficiaries can apply to the CMA to undertake the maintenance themselves. It has taken many decades to develop the current situation; it will also take time to remedy it. Decisions about which levees are to be formally managed will also take time. Regional floodplain management strategies will need to identify and prioritise flood risks in consultation with flood-prone communities. Part of this process will be to understand the standard of unmanaged regional urban levees as well as rural levees on Crown land. Specifically, there is work to be done in estimating: the costs of restoring the levees to a reasonable standard of protection the costs of ongoing maintenance the benefits of restoring and maintaining the levee the costs and benefits of alternative solutions. If the benefiting community, through the LGA, judges that their one-third share of the likely capital cost of restoring a large-scale regional urban levee is affordable, and their ongoing contributions to management and maintenance costs are also affordable. If the overall benefits outweigh the costs, then it will be worthwhile and necessary to carry out more detailed investigation. If the benefiting community judges otherwise, the regional urban levees will not be formally maintained. Revised Draft Victorian Floodplain Management Strategy 56

189 Part Formalising the management of existing regional urban infrastructure LGAs wanting to bring existing regional urban flood mitigation infrastructure into formal management arrangements will require guidance on the process and requirements for sustainable maintenance. LGAs will be free to decide whether they want to formalise future management arrangements, in consultation with their local communities. However, if government funding is provided towards the upgrade, it may be conditional on the LGA agreeing to manage the infrastructure formally. For large-scale infrastructure, this would preferably be implemented through a Water Management Scheme. However, there may be instances, e.g. in enlarging a road culvert or raising a road, where alternative arrangements are demonstrably more appropriate. Proposed Action 17b DELWP will consult and collaborate with relevant LGAs to develop a process to provide for existing flood mitigation infrastructure to be implemented as Water Management Schemes. That process will: begin with an assessment of the condition of the infrastructure and its standard of protection, based on the best available information derived from flood studies consider options to upgrade the infrastructure to contemporary design standards identify, in consultation with the benefiting community, the most cost-effective option that is in keeping with community s willingness and ability to pay for ongoing management and maintenance costs establish ongoing management arrangements Cost-sharing arrangements The capital cost of bringing existing regional urban infrastructure up to acceptable standards for incorporation into a Water Management Scheme will be shared in the same manner as the capital costs of new infrastructure. As with new infrastructure, the beneficiaries of existing infrastructure that is to be brought under formal management arrangements to protect urban areas will be required through their LGA to meet the ongoing costs of management, maintenance and auditing. The benefits of avoiding disruption to the functioning of urban areas often extend throughout the region s economy. Flood mitigation infrastructure intended primarily to benefit urban areas may also deliver benefits to rural areas, for example by keeping hospitals, schools, and other community services operational. For these reasons, it is appropriate that LGA raise the necessary revenue across its municipality. The Victorian Government will work with local government to determine further guidance on cost sharing arrangements if required.opting to leave existing urban infrastructure unmanaged and unmaintained At any stage before or during the processes outlined above, LGAs will be free to make conscious decisions to not maintain existing urban infrastructure. However, if they choose not to, their Planning Schemes and their emergency management plans must take account of the impacts of that decision. The Municipal Planning Scheme must, in effect, assume that the infrastructure does not exist. The appropriate zones and overlays should apply to all land within the 1% AEP flood level, regardless of whether it is behind the levee or not. Floor levels for new dwellings should be built above the 1% AEP flood level, including an allowance for freeboard. In contrast, the Municipal Flood Emergency Plan should assume that the infrastructure does exist and that it is liable to sudden and complete failure, unless (subject to a flood study) the infrastructure is formally decommissioned. Proposed Policy 17c Where there is unmanaged flood mitigation infrastructure in an urban area: the relevant Municipal Planning Scheme must not assume that the infrastructure will provide flood protection the relevant Municipal Flood Emergency Plan must provide for the potential for sudden and complete failure of that infrastructure. Revised Draft Victorian Floodplain Management Strategy 57

190 Part Decommissioning flood mitigation infrastructure On rare occasions, after consultation with their local communities, councils may choose to decommission existing flood mitigation infrastructure. The process for decommissioning will involve: commissioning a study to evaluate impacts developing a strategy to manage those impacts in consultation with the local community communicating the results of the decision, giving due consideration to the benefits of decommissioning the flood mitigation infrastructure against the costs and disadvantages. In most situations, it may be more appropriate to leave existing flood mitigation infrastructure unmanaged, particularly if the infrastructure has not been formally maintained for some time. In some cases, individual landowners may wish to decommission a private levee. This would require a planning permit to enable third party impacts to be considered, and objections to be heard from neighbours Bringing government-built rural infrastructure into formal management arrangements In the past, Governments have had varying involvement in building flood mitigation infrastructure in rural areas. The Victorian Public Works Department (PWD) began constructing levees in 1895, with the construction of some 51 km of levees from Cobram to Yielima which offered some protection for those areas. Outside of any ad hoc contributions for repairs provided by government after floods such as those experienced in , these levees are not formally managed or maintained. As discussed in section , large-scale rural flood mitigation systems are generally no longer considered to be best practice. As also discussed in section 5 most of those systems were not subject to planning controls or engineering construction standards, and most early levees were built to poor standards with unsuitable soils and little understanding of their ongoing maintenance implications. And as discussed at the start of section 17, the floods of revealed serious deficiencies in the management arrangements for flood mitigation infrastructure outside Melbourne. Most rural flood mitigation infrastructure has not been maintained. Notwithstanding these legacy issues, the Victorian Government acknowledges that it is possible that some government-built infrastructure may still be offering flood protection services that provide public benefits. If that is the case, there may be instances where it is appropriate to bring those systems into formal management arrangements. If a regional floodplain management strategy identifies that existing government-built rural infrastructure is providing significant public benefits it will be possible to bring that infrastructure into formal management arrangements using essentially the same process described in section 17.3 for regional urban infrastructure. That process would begin with a flood study to assess the benefits and the costs associated with maintaining the infrastructure to an agreed standard of flood protection as well as an assessment of the community s willingness to pay. It is important to define the public benefits of interest to government in this process. These benefits would be confined to reducing the risks to life and property and would predominately be protecting towns or essential infrastructure that underpins the regional economy. The benefits in Revised Draft Victorian Floodplain Management Strategy 58

191 Part 3 terms of agricultural production or businesses would be considered primarily to be private benefits. The government also expects that any contribution from LGAs would also be concerned with, and commensurate with, only those public benefits not private benefits. Where a flood study demonstrated that the public benefits would exceed the public costs, the Victorian Government would be willing to enter into cost sharing arrangements similar to those outlined in section to help bring previously governmentbuilt, riverine, flood mitigation infrastructure back to an agreed standard of repair. The repaired infrastructure would be implemented as a Water Management Scheme developed in consultation with the flood-affected community. The main challenge for all parties to the cost sharing arrangements would be agreeing on the standards of repair. Assuming that the cost-benefit ratios would not support rebuilding the existing infrastructure to contemporary standards, the reality would involve partial repairs to infrastructure of uncertain standards. This would raise questions of liability. All parties would be understandably nervous about assuming any liability for the failure of unrepaired parts of that infrastructure. The current Victorian Government statutory immunity policy is that immunity provisions are rarely appropriate because they remove the legal rights that would otherwise be available to a person who has suffered loss. A complete statutory immunity is not appropriate because it can remove the incentives for a person or body to exercise a reasonable level of care. Ideally the Water Management Scheme arrangements would seek to codify what would constitute a reasonable level of care in the context of the available finances. The aim would be to help ensure actions taken in good faith in the performance of agreed maintenance functions and duties would be taken into account in determining liability. Financial resources, compliance with applicable general standards and the state of scientific knowledge of local conditions would all influence judgements about reasonable levels of care. Formal arrangements take time to establish. Regional floodplain management strategies will have to identify priorities, flood studies will have to take place and water management schemes will have to be established. And even after those steps, communities may determine that they are not willing to make the ongoing financial contribution to maintenance that is required; consequently they may not support the proposed formal management arrangement. In such cases documenting community decision making is important. Documenting the decision making process through Water Management Schemes is intended to demonstrate a formal process has been undertaken and avoid any expectation that LGAs will be maintaining rural levees outside of those areas agreed to by the community. However, there may be instances where the formal management of a levee is the best option for the long term. As outlined below, however, these processes will not prevent landholders from carrying out maintenance on that infrastructure in between times Maintaining levees that are not formally managed While the benefits of a particular levee may not be recognised by a community (and therefore not managed through a formal scheme), there may be individuals who see benefit in that levee and wish to maintain it themselves. Where the levee is on private land, it will be for the private landowners and any other beneficiaries to negotiate amongst themselves arrangements for the ongoing maintenance of the levee. Landholders opting to jointly manage their own scheme may request LGA assistance. LGAs should negotiate the terms of assistance directly with the group. DELWP will work with local government to determine how these arrangements could work. There is no role for the state in the management of private levees. Where the levee is on Crown land, beneficiaries will be able to access that levee and maintain it themselves under new provisions that were added to the Water Act 1989 by Parliament in 2014 (see below) A permit system for levee maintenance on Crown land There are about 900 kilometres of existing levees on Crown land. In 2014, changes to the Water Act 1989 created a permit scheme so that people who benefit from those Crown land levees can apply to their local CMA for a permit to maintain it themselves. Previously, if they wanted to maintain the levee they needed to seek a variety of approvals. In some instances they needed to have had approval from Revised Draft Victorian Floodplain Management Strategy 59

192 Part 3 multiple land managers, with some land managers not having the power to give any approval at all. Under the new system, people will only need a single permit from their local CMA. Permit holders will be authorised to access the Crown land and maintain the levee in accordance with conditions on the permit. Permit holders will not be authorised to change the levee s original location, height and width, build a new levee, nor remove an old one, as this could affect third parties. CMAs and land managers, such as DELWP and Parks Victoria will set reasonable conditions on the permit to minimise the impact of maintenance activities on Crown land values. In some instances a person holding a Crown land levee maintenance permit may not be required to also hold a permit under the relevant Municipal Planning Scheme. Nonetheless, their maintenance activities will have to comply with other legal obligations such as those that protect Aboriginal and cultural heritage and environmental values Respecting Aboriginal and cultural heritage Aboriginal places and objects in Victoria, whether known or unknown, are protected under the Aboriginal Heritage Act 2006 and cannot be disturbed or destroyed without authorisation. Cultural Heritage Management Plans are required for proposed high-impact activities in listed areas of cultural heritage sensitivity, as defined in the Aboriginal Heritage Regulations Cultural Heritage Management Plans are a way to protect and manage cultural heritage, while allowing for some development. Applicants for levee maintenance permits will need to provide evidence of compliance with the requirements of the relevant Aboriginal cultural heritage authorities to avoid or minimise the impacts on any relevant sites or objects Respecting environmental values Floodplains are valuable places, not only for farms, communities and Aboriginal people, but also for the environment. It is important that actions to protect farms and communities from flood risk, do not diminish the environmental values. It is also important to take into account the benefits to the environment that flooding provides. The Victorian Government currently protects environmental values through a number of Acts of Parliament. Each of these Acts protects environmental values through different approval processes. The segmentation of these approvals can place individuals in a position where they are hesitant about taking action to protect themselves against flood risk. For this reason, DELWP is working to streamline environmental approvals in relation to floodplain management. Proposed Policy 17d The beneficiaries of levees on Crown land that are not formally managed will be able to maintain the height and width of those levees under a Levee Maintenance Permit scheme. Permits to maintain levees on Crown land will be subject to conditions specified by both the Crown land manager and the Minister for Water or a delegate such as a CMA. Applicants for levee maintenance permits will need to ensure their activities comply with Aboriginal cultural heritage requirements if relevant. Proposed Action 17c DELWP will prepare guidance material, including an Application Kit, on how to apply for a permit to maintain levees on Crown land that will include practical advice on: how applicants can meet their obligations to protect environmental values how applicants can seek to meet their obligations to protect Aboriginal cultural heritage. CMAs will make these guidelines available at their offices and on their websites Dam operations Victoria s large dams are not designed to mitigate floods, they are designed to provide water supply and irrigation services. Any flood mitigation from a Victorian dam is incidental and opportunistic; it depends on the water level in the dam at the time of flood-inducing rain. Dams with regulating gates are operated to protect the safety of the dam and to maximise the storage of water. Fixed spillways also serve to keep large dams at safe operating levels and to allow floodwaters to pass. The management arrangements for large flow releases from dams are articulated in an attachment to the State Flood Emergency Plan: Management of flooding downstream of dams. Revised Draft Victorian Floodplain Management Strategy 60

193 Part 3 Although it is very unlikely that a well-constructed and maintained dam would fail, this extremely rare event could release large volumes of water. Owners of large dams have produced flood inundation maps showing predicted flow paths and levels of the water that could be released in these unlikely circumstances. Dam owners are required to maintain these maps and make them available to Incident Controllers during emergencies Cross-border issues The floods brought into focus long-standing issues about the lack of integration in cross-border approaches to the design and management of flood mitigation infrastructure. Communities on both sides of the Victoria-New South Wales border expressed concerns that levees on one side had aggravated flood impacts on the other. They also had concerns that neither state was doing enough to share floodwaters, and flood storage capacity, through the integrated operation of regulators. Cross-border issues are complex. The history of efforts to resolve these issues date back to 1910 when NSW and Victoria entered a formal Interstate Levees Agreement. Centralised efforts to coordinate levee construction persisted, nominally at least, until 2008 when the Murray-Darling Basin Commission was abolished. They were not successful, partly because flood behaviour is more complex than envisaged more than a century ago. The trade-offs involved in floodplain management can really only be resolved at the local level. This Strategy aims to foster greater cooperation across the border at the local level. Building trust and goodwill at the local level starts with an understanding of the differences in institutional arrangements that govern floodplain management in each state. For example: levees in NSW are licensed, in Victoria they are not levee approval is centrally regulated in NSW (via the NSW Water Management Act 2000), but approval processes in Victoria are more diffuse the statutory planning roles of local government are different. While there are differences in the framework and accountabilities in each state, the overall objectives and desired outcomes are similar. DELWP will work with its NSW counterparts, and to consultwith relevant agencies and organisations, to establish processes for integrated floodplain management across borders. Future regional floodplain management strategies with cross-border components will be prepared in consultation with relevant agencies from both states. In meeting this commitment, some basic protocols will need to be established. For example, NSW and Victoria should agree that: all future flood studies conducted on the Murray will consider both sides of the river all committees established to oversee the development of flood studies on the Murray will include representatives from both states all flood maps for the Murray will be made available to both states flood intelligence from both sides of the border will be shared and made available to emergency management planners and to incident managers from both states emergency managers on both sides of the border should conduct joint training exercises and the preparation of flood emergency management plans should include representation from both states upgrades to flood warning systems on crossborder systems, including the Snowy, should involve the relevant authorities from both states the operating procedures for all dams, weirs, locks and regulators capable of influencing flood behaviour on cross-border systems, including the Snowy, should be documented in emergency response plans on both sides of the river there should be no increase in the height or length of existing levees on the Murray without triggering a cross-border referral both states should revise their approval processes to include cross-border referrals. Revised Draft Victorian Floodplain Management Strategy 61

194 Part 3 Proposed Policy 17e The Victorian Government will take a no borders approach to floodplain management on the Murray River: All proposals for flood mitigation activities on the Victorian side of the river, other than for minor works such as a ring levee around a house and curtilage, will be referred to appropriate NSW agencies for advice. Relevant NSW agencies will be encouraged to actively participate in the development of relevant regional floodplain management strategies. Existing forums, such as the Murray Group of Councils, will continue to be used to share information across the NSW and Victorian border. Proposed Action 17d DELWP will approach the NSW Government with a view to establishing formal arrangements for: constructing and managing new flood mitigation infrastructure sharing information improving emergency management planning processes considering joint studies and strategies considering whether the MDBA or some other group could act as a sounding board for major initiatives or issues coordinating emergency management planning. DELWP s guidelines will require regional floodplain management strategies to take account of cross-border issues and actively seek participation from NSW counterparts. DELWP will work with NSW agencies to review the need for flood warning upgrades along the River Murray. Municipal Emergency Response Plans will include cross-border issues. 18 Flood mitigation activities on waterways The Victorian Waterway Management Strategy (2013) provides the framework for maintaining and improving the condition of Victoria s rivers, estuaries and wetlands. It aims to ensure that waterways continue to support environmental, social, cultural and economic values for all Victorians. Flood mitigation activities on waterways (such as vegetation clearance, debris removal and sediment removal) must be carried out in ways that are consistent with the VWMS. The CMAs and Melbourne Water have statutory responsibilities for waterway health and waterway management. Their regional waterway strategies outline regional goals for waterway management and result in works programs developed in consultation with local communities. Proposed Policy 18a Regional floodplain management strategies will be aligned, as closely as practicable, with the policies and objectives of relevant regional waterway management strategies. The CMAs and Melbourne Water also have a regulatory role, under the Water Act 1989, in authorising individuals and organisations to carry out flood mitigation activities on waterways. However, they do not have a responsibility to carry out flood mitigation activities on waterways themselves. If the beneficiaries are willing to cover these ongoing costs, Melbourne Water and the CMAs will help to enable those activities in accordance with state and regional waterway management strategies. Melbourne Water and the CMAs are responsible for large-scale works to manage waterway erosion and to provide advice to minimise the risk of avulsions. They are also responsible for setting regional priorities in the planning, construction and restoration of flood mitigation activities on waterways. Proposed Accountability 18a Melbourne Water and the CMAs are accountable, on a priority basis, for works to manage large-scale waterway erosion. Melbourne Water and the CMAs are accountable for providing advice to minimise identified risks of avulsions. Revised Draft Victorian Floodplain Management Strategy 62

195 Part An authorisation framework for flood mitigation activities on waterways The Victorian Government is putting in place a framework to enable individuals, infrastructure managers, LGAs and other authorities to carry out flood mitigation activities on waterways. The framework will deal with large-scale flood mitigation projects that typically benefit urban communities, as well as small-scale activities that may benefit individual landholders Authorisation for larger-scale activities for urban areas For larger-scale flood mitigation activities on waterways, say for sediment or vegetation removal intended to reduce flood risks at the township scale, a flood study will be required before authorisation is granted. If a flood study demonstrates that flood risks can be materially reduced by flood mitigation activities on waterways, it is likely that they will need to be carried out regularly. It is rare for these activities to be one-off jobs; vegetation regrows and sediments are always being deposited in streams. It is important for the beneficiaries to consider whether they are willing and able to meet those ongoing costs. The costs to waterway health, in terms of biodiversity and geomorphology would also need to be understood. If an LGA wants to carry out flood mitigation activities that have demonstrated benefits, it will be able to apply to the relevant CMA or Melbourne Water for authorisation to do so. Authorisation will be subject to conditions designed to ensure that the costs to waterway health, if any, are commensurate with the demonstrated flood mitigation benefits. Authorisation will include a requirement to complete activities within a defined timeframe typically 12 months. If an LGA wants to secure approvals for longer-term ongoing activities they will also have the option to apply to implement them as Water Management Schemes under the Water Act The processes involved in establishing a Water Management Scheme are described in section Proposed Policy 18b Where flood studies demonstrate that flood risks can be materially reduced by large-scale flood mitigation activities on waterways, individuals or LGAs will be able to carry out those activities subject to authorisation granted by the CMAs or Melbourne Water. If a waterway is to be modified or if vegetation, debris or sediment is to be removed from a waterway for flood mitigation purposes, and these activities are to be implemented as Water Management Schemes, the relevant LGA or other authority responsible for implementing the scheme will be responsible for undertaking the work (in compliance with any relevant conditions) and for all ongoing maintenance. Large-scale flood mitigation activities on waterways must be demonstrated, through a flood study, to be cost effective, i.e. have demonstrable benefits in terms of reduced average annual damage (AAD) that are greater than any costs to waterway health. Proposed Action 18a DELWP will prepare guidelines on how to apply to a CMA or Melbourne Water for authorisation to carry out works on waterways. These guidelines will include practical advice on how to meet Aboriginal and cultural heritage protection requirements. They will also include practical advice on how to meet environmental protection requirements. CMAs and Melbourne Water will make these guidelines available at their offices and on their websites. Revised Draft Victorian Floodplain Management Strategy 63

196 Part Authorisation for small-scale activities Where individuals, groups of landholders, infrastructure managers, LGAs or other authorities propose small-scale activities to remove vegetation or flood debris, CMAs will use risk assessment guidelines prepared by DELWP to help them determine whether these activities can be authorised without the need for a flood study. Proposed Policy 18c Individuals or groups of landholders, infrastructure managers, councils or other authorities (unless formally exempt) proposing small-scale activities to remove vegetation, remove sediment or to remove or realign debris from a waterway must obtain authorisation from the relevant CMA or Melbourne Water. When determining whether to grant authorisation for proposed activities, the relevant CMA or Melbourne Water will consider potential risks to waterway health. The CMA or Melbourne Water may require the proponent to undertake alternative activities to minimise any risks Linkage with the rural drainage strategy DELWP proposes that it will prepare a rural drainage strategy that will provide strategic guidance for matters relating to rural drainage. This will include consideration of clearing a stream of debris or sediment that may have multiple benefits (e.g. flood mitigation, rural drainage and waterway management) and involve the same activities and potential costs. Flooding at Lake Wallawalla. Source: Mallee CMA Revised Draft Victorian Floodplain Management Strategy 64

197 Part 3 19 Business continuity plans for critical infrastructure Some infrastructure is critical to the health, safety and prosperity of the Victorian community. The Victorian Critical Infrastructure Resilience Strategy (VCIRS) and Part 7A of the Emergency Management Act (the Act), which come into effect on 1 July 2015, outline measures that owners and operators of critical infrastructure should take to manage the emergency risks that will have an impact on essential service delivery. The owners and operators of critical infrastructure assessed as vital under the Act will be responsible for developing and implementing site specific strategies to mitigate and manage the effects of risks (including risks from natural hazards such as flooding) to the continuity of essential services. Government departments also have responsibilities in assisting and monitoring the performance of vital critical infrastructure. The Act requires owners and operators of vital critical infrastructure to undertake mandatory risk management activities to build their resilience to all hazards. The Act is designed to optimise the risk-management practices already undertaken by owners and operators of vital critical infrastructure and will create a flexible assurance framework. In developing appropriate flood mitigation strategies, the operators of vital critical infrastructure may need to undertake a flood risk assessment. DELWP will make available any relevant flood-related material for this assessment. It is possible that some critical infrastructure, despite being covered by adequate flood risk mitigation plans in the short to medium term, is nonetheless at long-term risk from waterway processes. For example, it may be that the functioning of a bridge or weir is at identified risk from a river avulsion due to natural flood-related processes. In these cases, Melbourne Water and the CMAs can provide relevant information to enable the infrastructure operator to develop longer-term risk management strategies. Proposed Accountability 19b Melbourne Water and the CMAs are accountable for monitoring the condition of waterways to assess the risks of large-scale erosion and avulsions. Proposed Action 19a DELWP in consultation with the CMAs and Melbourne Water and representative asset owners will develop principles for managing serious risks to public infrastructure from waterway processes (see Victorian Waterway Management Strategy [2013] Action 4.2). This will be done in accordance with the principles and obligations outlined in the VCIRS and any relevant legislation. Proposed Accountability 19a The operators of essential service infrastructure are accountable for: assessing the risks posed to their operations by flooding developing and implementing fit-for-purpose flood risk mitigation plans for each facility at risk of flooding developing fit-for-purpose flood response plans. Revised Draft Victorian Floodplain Management Strategy 65

198 Part 4: Managing residual risks Rural flooding Source: North-East CMA Revised Draft Victorian Floodplain Management Strategy 66

199 20 Flood insurance The Federal Productivity Commission Report on Natural Disaster Funding Arrangements, released on 1 May 2015, supports the need for greater emphasis on mitigation and recognition of the role of government in fostering the establishment and development of an appropriate flood insurance regime for Australia. At the most fundamental level, governments have a role in ensuring that: individuals and communities affected by floods are able to recover and rebuild as quickly as possible people are able to choose where they live in an informed way (the inference being that the relative size of flood insurance premiums in different locations provides an important signal) individuals and communities at risk of future flooding are aware of the risks and are able to obtain suitable protection against those risks both in terms of having access to insurance and in benefiting from appropriate mitigation strategies. The Australian Government, in response to NDIR s 47 recommendations: introduced a standard definition of flood for inclusion in all insurance policies offering flood cover committed to the introduction of a national portal to improve the coordination, and the public availability, of flood risk information undertook to consult with relevant stakeholders on other recommendations. The Insurance Council of Australia (ICA), which represents more than 90% of the total premium income written by private sector general insurers, released a 10-point plan aimed at developing a more effective and sustainable response to disasters in Australia. The ICA believes that government has three key roles in supporting flood insurance: ensure the availability of high-quality information about flood risk [section 11] mitigate the legacy of existing flooding exposure [sections 17.2 and 17.3] prevent the flood-prone population expanding [sections 13.4 and 13.6]. Part 4 These three roles have long been seen as core business for government. Nonetheless, the NDIR, the Environment and Natural Resources Committee (ENRC) inquiry into flood mitigation infrastructure and the Victorian Floods Review (VFR) revealed considerable scope for improvement in how each of those roles was being fulfilled prior to the floods. This Strategy addresses those necessary improvements. Of those three roles, it seems likely that there is particular scope for improving the availability of, and access to, high-quality information about flood risk. Partly this is a result of the ongoing revolution in information management, but partly it is a consequence of the relative infancy of the flood insurance industry in Australia. Proposed Policy 20a The Victorian Government will work with the insurance industry to share flood data in an efficient and practical manner, including access to digital elevation data and flood mapping held by DELWP. Proposed Action 20a DELWP will seek ongoing access to the National Flood Information Database, used by most insurers as a core input when assessing flood risk at the address level across Victoria. DELWP will work with the insurance industry to ensure that insurance premiums take account of the benefits of formally managed flood mitigation infrastructure as well as the mapped flood risk profiles for individual properties. Revised Draft Victorian Floodplain Management Strategy 67

200 Part 4 21 Disclosing flood risk information As outlined in section 13.1, land use planning provisions do not apply to land subject to inundation by floods less likely than the 1% AEP flood. When they do occur, floods larger than a 1% AEP will cause significant damage and considerable associated costs. It is important for people living and working in those flood-prone areas to be able to make informed decisions about risk management. It is also important to ensure that essential infrastructure, such as roads, telecommunications and gas lines are sited in locations commensurate with the flood risk. In many places, flooding in extended well beyond the 1% AEP flood. Emergency management agencies need to be able to plan with their communities for such flooding; they also need to be able to issue accurate and timely warnings. This flood information needs to be provided in a manner that does not unnecessarily alarm communities, particularly where flooding beyond the 1% AEP flood may cause short-term inconvenience or nuisance rather than a risk to property, livestock or safety Comprehensive flood mapping The Victorian Flood Database (section 11.3) contains several layers of modelled flood extents for a range of floods from moderate to extreme. The starting point for disclosing flood risk information is to make sure that these maps are in the public domain and readily accessible. Individuals armed with high-quality information about their exposure to flood risks ought to be in a position to negotiate insurance premiums that reflect that risk. They can now seek this information from CMAs. In an ideal world, insurance premiums would vary with the mapped range of flood probabilities from moderate to extreme. Insurers would, however, have to take account of the less certain risk of flooding associated with urban drainage systems on top of the better-understood risks of riverine flooding. Proposed Policy 21a The Victorian Government will seek to ensure that individuals can have full disclosure of the flood risks associated with their property, not just information relating to the 1% Annual Exceedance Probability flood Vendor disclosure statements One of the guiding principles underpinning this Strategy is that people living on floodplains should be able to make informed choices about the risks they face. Similarly, people considering whether to buy properties on floodplains should be informed about flood risks before deciding to buy. Making this information more accessible is key to enabling individuals to make informed choices about managing their own risks. It is also key to ensuring economic efficiency in the insurance market and the land market. In a world where flood risks are mapped, those risks should be priced into land values. Developers in these situations should be able to identify the full costs of their proposals, including costs in the form of Average Annual Damage (AAD). By contrast, where flood risks are not mapped, those risks are unlikely to be priced into land values because the flood risks (and potential development constraints) are not recognised. The dilemma for governments is that once flood risks are mapped, if those risks are not adequately communicated then, in economic terms, they make for information asymmetry. That is, people selling land on floodplains may have more information than potential buyers. This distorts land markets. One way to avoid distorting the land market would be to include the probability of flooding on the vendor statements required by the Sale of Land Act At their most fundamental level, these statements are intended to ensure the disclosure of information that may have a bearing on the decision to buy the property or the price to be offered. Bush fire risks are now disclosed on these statements. Planning controls in the form of zones or overlays must also be disclosed. People buying land in those municipalities that incorporate flood provisions into their local Planning Schemes already receive this Revised Draft Victorian Floodplain Management Strategy 68

201 Part 4 information on disclosure statements. Assuming that all relevant Planning Schemes will eventually include appropriate flood zones and overlays, including the probability of flooding on the vendor statement would be aimed at people buying properties outside the 1% AEP flood level. One option could involve the determination of designated flood prone areas in Building Regulations. Such designated areas, which would extend beyond the 1% AEP flood level, would need to be referenced to flood maps made publicly available on the land channel website ( vic.gov.au). This would require a different format to the maps currently held in the relevant flood databases. Another approach could involve adding a simple statement to the list of those already included on the vendor statement. For example, this could be similar to the one that currently applies to commercial agricultural production. It serves to advise the purchaser that it is in their interest to investigate the impacts of the local agricultural practices and processes. The right words could encourage individuals to actively involve themselves in understanding their own flood risks; it would not increase the administrative burden on CMAs or LGAs. Either approach would require legislative change. Each would also increase the demand to make flood maps publicly available. Consumer Affairs Victoria currently produces a Due Diligence Checklist for prospective buyers that includes the following question: Does this property experience flooding? It goes on to say Properties are sometimes subject to the risk of flooding due to their location. You should properly investigate these risks and consider their implications for land management, buildings and insurance premiums. Proposed Action 21a DELWP will consult with Consumer Affairs Victoria to review the application of the Due Diligence Checklist. The aim will be to determine the administrative and legislative issues involved in including flood risk information on vendor disclosure statements in the future. 22 Integrated flood emergency management A key objectives of emergency management (as set out in Section 5 of the Emergency Management Act 2013: Objectives of Act) is a system that minimises the likelihood, effect and consequences of emergencies. In Victoria, emergency management has been structured around three separate but interdependent components: Prevention: reducing or eliminating the incidence or severity of emergencies and mitigating their effects. Response: combating emergencies and providing rescue and immediate relief services. Recovery: assisting people and communities affected by emergencies to achieve a proper and effective level of functioning. Statewide accountability for these three components needs to be assigned and tailored for particular hazards and organisations. DELWP, Melbourne Water and the CMAs have primary responsibility to work with LGAs and VICSES on prevention activities. VICSES is the control agency for flood in Victoria, a function that, in a major flood, is exercised by the Emergency Management Commissioner. The Emergency Management Commissioner is responsible for coordinating recovery activities for all emergencies. However, this responsibility is currently delegated to the Secretary of the Department of Health and Human Services. VICSES is responsible for the community education and awareness that underpins flood preparedness. This includes its Flood Safe Program. Acting in support of Municipal Emergency Management Planning Committees, VICSES is also responsible for preparing Municipal Flood Emergency Plans with support from the relevant LGA. The PRR approach (prevention, response and recovery) used in Victoria is a variation of the PPRR approach (prevention, preparedness, response and recovery) to emergency management used in some other jurisdictions. Revised Draft Victorian Floodplain Management Strategy 69

202 Part 4 Proposed Accountability 22a VICSES is accountable for leading infrastructure managers and technical experts in contributing to the development of Flood Emergency Planning. This includes the development of a State Flood Emergency Plan, Regional Flood Emergency Plans and Municipal Flood Emergency Plans. Emergency management agencies are informed by the flood mitigation measures in place; these are then incorporated into flood emergency plans. Similarly, those flood mitigation measures should be designed and implemented in the expectation that emergency management accessways and evacuation routes may be needed. Floodplain management services must seek to address the needs of other agencies. For example, DELWP is responsible for flood mapping but the maps it prepares must meet a range of business requirements within and outside the department. Those maps must be designed to: underpin land use planning identify high flood risk areas for targeted mitigation works support emergency warnings issued by incident controllers underpin emergency management arrangements developed by VICSES and LGAs indicate priority areas for recovery efforts. The flood studies conducted by Melbourne Water and the CMAs should deliver outputs tailored towards the completion of VICSES s template for Municipal Flood Emergency Plans. Specifically, they should aim to describe: flood threats typical flood peak travel times an overview of flooding consequences an overview of existing flood mitigation infrastructure an overview of flood impacts and required actions flood warning systems maps. The institutional challenge is to make sure all these things are integrated. The Inspector General for Emergency Management has a role to provide assurance to the government and the community regarding Victoria s emergency management arrangements. Proposed Accountability 22b Melbourne Water and the CMAs are accountable for making sure that the outputs of their activities can be integrated with other emergency management functions. When a levee is overtopped, there is a chance that it could fail suddenly and completely. Emergency management plans must include evacuation options. Proposed Action 22a Flood emergency plans will make reference to the overtopping or failure of flood levees and their possible consequences. Incident Controllers will determine how best to deal with the issue of a levee overtopping or failing. DELWP, CMAs and Melbourne Water will provide technical advice to assist Incident Controllers in planning around levee failure. Emergency services supplying sandbags at Nathalia. Source Goulburn Broken CMA Revised Draft Victorian Floodplain Management Strategy 70

203 Part 4 23 Incident control During flood incidents, DELWP, the CMAs and Melbourne Water (Melbourne Water) will provide Incident Controllers with advice and support, in accordance with the Emergency Management Manual Victoria. The roles of the CMAs and DELWP are interdependent. In broad terms, DELWP relies on the CMAs for detailed advice about specific incidents; the CMAs rely on DELWP for strategic advice and assistance. Flood response activities in Victoria are managed under the State Emergency Response Plan (Part 3 of the Emergency Management Manual Victoria). Using an Incident Management System, the Incident Controller establishes a control structure to suit the circumstances and leads the development of a multi-agency Incident Action Plan, including objectives and strategies to manage the incident. Emergency response management operates at three tiers, incident, regional and state. Collaborative multi-agency forums (e.g. Emergency Management Teams) are used during emergencies to identify and discuss the risks and likely consequences of the emergency and assist the controller to establish priorities. Such teams generally include DELWP (at the state tier) or CMA (at regional level) to provide flood information interpretive services. Proposed Accountability 23a VICSES, with support from DELWP, is accountable for determining the necessary qualifications and competencies required to provide specialist services to Incident Controllers during floods. DELWP, Melbourne Water and CMAs are accountable for maintaining the expertise to provide flood-specialist services to Incident Controllers during floods. VICSES is accountable for ensuring arrangements are in place to access flood-specialist services during floods. The Victorian State Emergency Services Act 2005 includes provisions to protect VICSES directors, employees, registered members, probationary members and volunteer emergency workers from liability for actions taken in good faith in the performance of their functions and duties. The State and its agencies, however, may be liable for actions that lead to injury or damage. DELWP, CMAs Melbourne Water and other water corporations may be requested to provide additional resources, under the direction of the Incident Controller, to help manage the flood response. For example, acting in providing additional resources, Melbourne Water and the CMAs may be asked to help clear debris during or immediately after a flood, provided the working conditions are safe. Similarly, Incident Controllers may request support agencies to build temporary levees, or modify or breach existing levees, subject to safety considerations. Such actions hold the potential to adversely affect individuals, even though they are intended to increase the overall public good. Individuals may also wish to take measures to mitigate against risks to their private property or infrastructure. Individuals should do so with regard to the liability for any actions that may lead to injury or damage. Proposed Policy 23a The construction of temporary levees, diversion of waterways diversions or alteration of existing flood mitigation infrastructure will only be undertaken during floods under the direction of Incident Controllers. Proposed Action 23a VICSES will develop a process to enable the evaluation and authorisation of emergency works for flood response. A large part of flood response and recovery cost relates to impacts from high-energy flows in rivers and streams. They include accumulation of flood debris, erosion of the bed and banks, siltation and avulsions. Often, fences protecting riparian vegetation may also be lost or damaged. Melbourne Water and the CMAs may, if requested, provide surge capacity to the Incident Controller during flood events to help deal with these issues in the context of the emergency. In the first instance though, asset owners are accountable for the functioning of their assets (section 19). For example, if debris builds up against a bridge or culvert, or behind a dam, the manager of the asset is expected to remove the debris. Emergency management agencies will need to work with Aboriginal people to help ensure Victoria s emergency management arrangements take into account the risks to Aboriginal cultural heritage. The State strategic control priorities (which form the basis of the Incident Strategy and Incident Action Planning processes) already include the protection of environmental and conservation assets and makes explicit reference to their cultural values. Revised Draft Victorian Floodplain Management Strategy 71

204 Part 4 24 Managing residual water Water remaining in the landscape after flood peaks have passed can pose risks to human health, community wellbeing and the functioning of regional economies. Emergency managers sometimes need to take steps to manage this residual floodwater. The response component of the emergency management system is focused on managing the impacts of the flood peak. Once the flood peak has passed, there is a transition from response to recovery activities. Decisions about the management of residual water are likely to be required during the transition period. Planning for the management of residual water can begin during the response period, provided it does not interfere with response activities. The key decisions are when (and if) to start pumping floodwater and when to stop. Intervention is required if existing drainage is not expected to remove the water in time to prevent unacceptable risks to life, human health, community wellbeing, or economic activity. Intervention should stop once these risks have been reduced to tolerable levels. Intervention also involves risks. These include workplace safety, and damage to property and the environment. Intervention can also create community expectations that pumping will continue until all floodwaters have been removed, which may not be practical or possible. 25 Planning for delivery of the Strategy The Final Strategy will include an implementation plan that will set out the preferred actions to manage Victoria s floodplains and associated responsibilities. This chapter outlines the process for developing the implementation plan and next steps to develop a Final Strategy Implementation plan This Strategy seeks feedback on a range of proposals and options to help the Government set the direction for floodplain management in Victoria. Details of these proposals will be completed for the Final Strategy after feedback has been considered. An implementation plan will be prepared consistent with a Final Strategy that will outline times and targets for delivering key actions. The Final Strategy will also provide details on how these actions will be funded. The roles and responsibilities of the various organisations responsible for managing floodplains are outlined in the Strategy. The task of implementing the actions outlined in the Final Strategy will be based on these roles and responsibilities. Proposed Accountability 24a DELWP is accountable for maintaining guidelines for managing residual floodwater. Revised Draft Victorian Floodplain Management Strategy 72

205 Part Your chance to have a say This Strategy provides an opportunity for the community to help determine the direction for floodplain management in Victoria. The Victorian Government welcomes feedback on the Revised Draft Victorian Floodplain Management Strategy. Submissions must be in writing and may be ed to [email protected] or sent to: Victorian Floodplain Management Strategy PO Box 500 East Melbourne VIC 3002 The closing date for submissions is 8 August Next steps Submissions will be considered by an Interdepartmental Stakeholder Reference, along with additional stakeholder contributions, to inform the development of the Final Strategy, due for release by the end of You need to know: The information you provide in your submission, or in any other response, will only be used by DELWP and the Interdepartmental Stakeholder Reference Group to consider as part of the development of the Final Strategy. However, it may be disclosed to other relevant agencies as part of the consultation process. All submissions will be treated as public documents and will also be published on the internet for public access. All addresses, phone numbers and details will be removed before submissions are published on the internet. Formal requests for confidentiality will be honoured but freedom of information access requirements will apply to submissions treated as confidential. If you wish to access information in your submission once it is lodged with DELWP, you may contact the project team at the above address. Revised Draft Victorian Floodplain Management Strategy 73

206 Acronyms AAD Average annual damage AEP Annual exceedance probability ARI Average recurrence interval ARR Australian rainfall runoff BCA Building Code of Australia BoM Bureau of Meteorology BNHCRC Bushfire and Natural Hazards Cooperative Research Centre CMA Catchment Management Authority DELWP Department of Environment, Land, Water and Planning DEDJTR Department of Economic Development, Jobs, Transport and Resources DFE Design flood event DHHS Department of Health and Human Services DTPLI Department of Transport, Planning and Local Infrastructure ENRC Environment and Natural Resources Committee FIP flood intelligence platform IGEM Inspector General for Emergency Management ISRG Interdepartmental Stakeholder Reference Group LGA Local Government Authority LPPF Local Planning Policy Framework MFEP Municipal Flood Emergency Plan MSS Municipal Strategic Statements RAM Rapid Appraisal Method RCB Regional Coastal Board SPPF State Planning Policy Framework TFWS Total Flood Warning System VCIRIS Victorian Critical Infrastructure Resilience Interim Strategy VCS Victorian Coastal Strategy VFD Victorian Flood Database VFMS Victorian Floodplain Management Strategy VFR Victorian Floods Review VICCLI Victorian Climate Initiative VICSES Victoria State Emergency Service VPP Victorian Planning Provisions Revised Draft Victorian Floodplain Management Strategy 74

207 Glossary Adaptation Adjustment in response to actual or expected climate change or its effects, which moderates harm or exploits beneficial opportunities. Annual exceedance probability (AEP) The likelihood of the occurrence of a flood of a given or larger size occurring in any one year, usually expressed as a percentage. For example, if a peak flood flow of 500 m 3 /s has an AEP of 5%, it means that there is a 5% chance (that is, a one-in-20 chance) of a flow of 500 m 3 /s or larger occurring in any one year (see also average recurrence interval, flood risk, likelihood of occurrence, probability). Average annual damage (AAD) Depending on its size (or severity), each flood will cause a different amount of flood damage to a flood-prone area. AAD is the average damage per year that would occur in a nominated development situation from flooding over a very long period of time. If the damage associated with various annual events is plotted against their probability of occurrence, the AAD is equal to the area under the consequence probability curve. AAD provides a basis for comparing the economic effectiveness of different management measures (i.e. their ability to reduce the AAD). Average recurrence interval (ARI) A statistical estimate of the average number of years between the occurrence of a flood of a given size or larger than the selected event. For example, floods with a flow as great as or greater than the 20-year ARI (5% AEP) flood event will occur, on average, once every 20 years. ARI is another way of expressing the likelihood of occurrence of a flood event (see also annual exceedance probability). Australian rainfall and runoff (ARR) ARR is a national guideline for the estimation of design flood characteristics in Australia published by Engineers Australia. ARR aims to provide reliable (robust) estimates of flood risk to ensure that development does not occur in high risk areas and that infrastructure is appropriately designed. The edition is currently being revised. The revision process includes 21 research projects, which have been designed to fill knowledge gaps that have arisen since the 1987 edition was published. Avulsion The rapid abandonment of a river channel and the formation of a new river channel. Avulsions occur as a result of channel slopes that are much lower than the slope that the river could travel if it took a new course. Avulsions typically occur during large floods that carry the power necessary to rapidly change the landscape. Catchment The area of land draining to a particular site. It is related to a specific location and includes the catchment of the main waterway as well as any tributary streams. Coastal erosion Short-term retreat of sandy shorelines as a result of storm effects and climatic variations. Coastal flooding (inundation) Flooding of low-lying areas by ocean waters, caused by higher than normal sea level, due to tidal or storm-driven coastal events, including storm surges in lower coastal waterways. Coastal hazard assessments Coastal hazard assessments commonly define the extent of land expected to be threatened by coastal hazards (inundation, coastal erosion, coastal recession) over specific planning periods. They are typically used for development assessment purposes and to inform land-use planning considerations. In particular such assessments include consideration of future sea level rise scenarios, typically to the year Consequence The outcome of an event or situation affecting objectives, expressed qualitatively or quantitatively. Consequences can be adverse (e.g. death or injury to people, damage to property and disruption of the community) or beneficial. Curtilage The land occupied by a dwelling and its yard, outbuildings, etc, actually enclosed or considered as enclosed. Design flood event In order to identify the areas that the planning and building systems should protect new development from the risk of flood, it is necessary to decide which level of flood risk should be used. This risk is known as the design flood event. Revised Draft Victorian Floodplain Management Strategy 75

208 Glossary Development Development may be defined in jurisdictional legislation or regulation. This may include erecting a building or carrying out of work, including the placement of fill; the use of land, or a building or work; or the subdivision of land. New development is intensification of use with development of a completely different nature to that associated with the former land use or zoning (e.g. the urban subdivision of an area previously used for rural purposes). New developments generally involve rezoning, and associated consents and approvals. Major extensions of existing urban services, such as roads, water supply, sewerage and electric power may also be required. Infill development refers to the development of vacant blocks of land within an existing subdivision that are generally surrounded by developed properties and is permissible under the current zoning of the land. Redevelopment refers to rebuilding in an existing developed area. For example, as urban areas age, it may become necessary to demolish and reconstruct buildings on a relatively large scale. Redevelopment generally does not require either rezoning or major extensions to urban services. Flash flooding Flooding that is sudden and unexpected, often caused by sudden local or nearby heavy rainfall. It is generally not possible to issue detailed flood warnings for flash flooding. However, generalised warnings may be possible. It is often defined as flooding that peaks within six hours of the causative rain. Flood Flooding is a natural phenomenon that occurs when water covers land that is normally dry. It may result from coastal or catchment flooding, or a combination of both (see also catchment flooding and coastal flooding). Flood awareness An appreciation of the likely effects of flooding, and a knowledge of the relevant flood warning, response and evacuation procedures. In communities with a high degree of flood awareness, the response to flood warnings is prompt and effective. In communities with a low degree of flood awareness, flood warnings are liable to be ignored or misunderstood, and residents are often confused about what they should do, when to evacuate, what to take with them and where it should be taken. Flood class levels The terms minor, moderate and major flooding are used in flood warnings to give a general indication of the types of problems expected with a flood Minor flooding: Causes inconvenience. Low-lying areas next to watercourses are inundated which may require the removal of stock and equipment. Minor roads may be closed and low-level bridges submerged. Moderate flooding: In addition to the above, the evacuation of some houses may be required. Main traffic routes may be covered. The area of inundation is substantial in rural areas requiring the removal of stock. Major flooding: In addition to the above, extensive rural areas and/or urban areas are inundated. Properties and towns are likely to be isolated and major traffic routes likely to be closed. Evacuation of people from flood-affected areas may be required. Flood damage The tangible (direct and indirect) and intangible costs (financial, opportunity costs, clean-up) of flooding. Tangible costs are quantified in monetary terms (e.g. damage to goods and possessions, loss of income or services in the flood aftermath). Intangible damages are difficult to quantify in monetary terms and include the increased levels of physical, emotional and psychological health problems suffered by flood-affected people that are attributed to a flooding episode. Flood education Education that raises awareness of the flood problem, to help individuals understand how to manage themselves and their property in response to flood warnings and in a flood event. It invokes a state of flood readiness. Flood emergency management Emergency management is a range of measures to manage risks to communities and the environment. In the flood context, it may include measures to prevent, prepare for, respond to and recover from flooding. Flood emergency management plan A sub-plan of a flood-prone municipality s Municipal Emergency Management Plan. It is a step-by-step sequence of previously agreed roles, responsibilities, functions, actions and management arrangements for the conduct of a single or series of connected emergency operations. The objective is to ensure a coordinated response by all agencies having responsibilities and functions in emergencies. Revised Draft Victorian Floodplain Management Strategy 76

209 Glossary Flood hazard Potential loss of life, injury and economic loss caused by future flood events. The degree of hazard varies with the severity of flooding and is affected by flood behaviour (extent, depth, velocity, isolation, rate of rise of floodwaters, duration), topography and emergency management. Flood peaks The maximum flow occurring during a flood event past a given point in the river system (see also flow and hydrograph). The term may also refer to storm-induced flood peaks and peak ocean or peak estuarine conditions. Flood-prone land Land susceptible to flooding by the largest probable flood event. Flood-prone land is synonymous with the floodplain. Floodplain management plans should encompass all flood-prone land rather than being restricted to areas affected by defined flood events. Flood proofing of buildings A combination of measures incorporated in the design, construction and alteration of individual buildings or structures that are subject to flooding, to reduce structural damage and potentially, in some cases, reduce contents damage. Flood readiness An ability to react within the effective warning time (see also flood awareness and flood education). Flood risk The potential risk of flooding to people, their social setting, and their built and natural environment. The degree of risk varies with circumstances across the full range of floods. Flood risk is divided into three types existing, future and residual. Existing flood risk refers to the risk a community is exposed to as a result of its location on the floodplain. Future flood risk refers to the risk that new development within a community is exposed to as a result of developing on the floodplain. Residual flood risk refers to the risk a community is exposed to after treatment measures have been implemented. For example: a town protected by a levee, the residual flood risk is the consequences of the levee being overtopped by floods larger than the design flood; for an area where flood risk is managed by land-use planning controls, the residual flood risk is the risk associated with the consequences of floods larger than the DFE on the community. Flood severity A qualitative indication of the size of a flood and its hazard potential. Severity varies inversely with likelihood of occurrence (i.e. the greater the likelihood of occurrence, the more frequently an event will occur, but the less severe it will be). Reference is often made to major, moderate and minor flooding (see also flood class levels). Flood study A comprehensive technical investigation of flood behaviour. It defines the nature of flood hazard across the floodplain by providing information on the extent, depth and velocity of floodwaters, and on the distribution of flood flows. The flood study forms the basis for subsequent management studies and needs to take into account a full range of flood events up to and including the largest probable flood. Flood studies should provide new flood mapping for planning scheme inclusion, data and mapping for MEMPs, and a preliminary assessment into possible structural and non-structural flood mitigation measures. Flood warning A Total Flood Warning System (TFWS) encompasses all the elements necessary to maximise the effectiveness of the response to floods. These are data collection and prediction, interpretation, message construction, communication and response. Effective warning time refers to the time available to a flood-prone community between the communication of an official warning to prepare for imminent flooding and the loss of evacuation routes due to flooding. The effective warning time is typically used for people to move farm equipment, move stock, raise furniture, transport their possessions and self-evacuate. Floodplain An area of land that is subject to inundation by floods up to and including the largest probable flood event that is, flood-prone land. Floodplain management The prevention activities of flood management together with related environmental activities (see also floodplain). Flow The rate of flow of water measured in volume per unit time for example, cubic metres per second (m 3 /s). Flow is different from the speed or velocity of flow, which is a measure of how fast the water is moving for example, metres per second (m/s). Revised Draft Victorian Floodplain Management Strategy 77

210 Glossary Freeboard The height above the DFE or design flood used, in consideration of local and design factors, to provide reasonable certainty that the risk exposure selected in deciding on a particular DFE or design flood is actually provided. It is a factor of safety typically used in relation to the setting of floor levels, levee crest heights and so on. Freeboard compensates for a range of factors, including wave action, localised hydraulic behaviour and levee settlement, all of which increase water levels or reduce the level of protection provided by levees. Freeboard should not be relied upon to provide protection for flood events larger than the relevant design flood event. Freeboard is included in the flood planning controls applied to developments by local councils. Frequency The measure of likelihood expressed as the number of occurrences of a specified event in a given time. For example, the frequency of occurrence of a 20% annual exceedance probability or five-year average recurrence interval flood event is once every five years on average (see also annual exceedance probability, annual recurrence interval, likelihood and probability). Hazard A source of potential harm or a situation with a potential to cause loss. In relation to this handbook, the hazard is flooding, which has the potential to cause damage to the community. Hydraulics The study of water flow in waterways; in particular, the evaluation of flow parameters such as water level, extent and velocity. Hydrology The study of the rainfall and runoff process, including the evaluation of peak flows, flow volumes and the derivation of hydrographs for a range of floods. Intolerable risk A risk that, following understanding of the likelihood and consequences of flooding, is so high that it requires consideration of implementation of treatments or actions to improve understanding of, avoid, transfer or reduce the risk. Likelihood of occurrence The likelihood that a specified event will occur (see also annual exceedance probability and average recurrence interval). Local overland flooding Inundation by local runoff on its way to a waterway, rather than overbank flow from a stream, river, estuary, lake or dam. Can be considered synonymous with stormwater flooding. Mitigation Permanent or temporary measures (structural and non-structural) taken in advance of a flood aimed at reducing its impacts. Planning scheme zones and overlays Planning schemes set out the planning rules the state and local policies, zones, overlays and provisions about specific land uses that inform planning decisions. Land use zones specify what type of development is allowed in an area (e.g. urban (residential, commercial, industrial), rural, environmental protection). Overlays specify extra conditions for developments that are allowed in a zone. For example, flooding overlays specify that developments must not affect flood flow and storage capacity of a site, must adhere to freeboard requirements, and not compromise site safety and access. Probability A statistical measure of the expected chance of flooding. It is the likelihood of a specific outcome, as measured by the ratio of specific outcomes to the total number of possible outcomes. Probability is expressed as a number between zero and unity, zero indicating an impossible outcome and unity an outcome that is certain. Probabilities are commonly expressed in terms of percentage. For example, the probability of throwing a six on a single roll of a dice is one in six, or or 16.7% (see also annual exceedance probability). Rainfall intensity The rate at which rain falls, typically measured in millimetres per hour (mm/h). Rainfall intensity varies throughout a storm in accordance with the temporal pattern of the storm (see also temporal pattern). Likelihood A qualitative description of probability and frequency (see also frequency and probability). Revised Draft Victorian Floodplain Management Strategy 78

211 Glossary Regional Coastal Boards Members of Victoria s three coastal boards have been appointed by the Minister for Environment and Climate Change because of their experience and expertise in areas such as local government, coastal planning and management, tourism and recreational use of the coast. The functions of the Western, Central and Gippsland Coastal Boards, set out under the Coastal Management Act 1995, include developing regional coastal plans and providing advice to the Minister on regional coastal development issues. Risk analysis Risk is usually expressed in terms of a combination of the consequences of an event and the associated likelihood of its occurrence. Flood risk is based upon the consideration of the consequences of the full range of flood events on communities and their social settings, and the natural and built environment (see also likelihood and consequence). Risk management The systematic application of management policies, procedures and practices to the tasks of identifying, analysing, assessing, treating and monitoring flood risk. Riverine flooding Inundation of normally dry land occurring when water overflows the natural or artificial banks of a stream, river, estuary, lake or dam. Riverine flooding generally excludes watercourses constructed with pipes or artificial channels considered as stormwater channels. Stormwater flooding The inundation by local runoff caused by heavier than usual rainfall. It can be caused by local runoff exceeding the capacity of an urban stormwater drainage systems, flow overland on the way to waterways or by the backwater effects of mainstream flooding causing urban stormwater drainage systems to overflow (see also local overland flooding). Victoria State Emergency Services (VICSES) VICSES is a volunteer-based organisation that provides emergency assistance to the community. VICSES is the control agency during emergency responses to floods, storms, earthquakes and tsunamis in Victoria, and is the largest provider of road rescue in the state. It also assists as a support agency during other emergencies such as fire. Vulnerability The degree of susceptibility and resilience of a community, its social setting, and the natural and built environments to flood hazards. Vulnerability is assessed in terms of ability of the community and environment to anticipate, cope and recover from flood events. Flood awareness is an important indicator of vulnerability (see also flood awareness). Water Management Scheme The formal process set out in the Water Act 1989 that can be applied to a flood mitigation infrastructure development and its ongoing management. It can be based on and carried out in parallel with a floodplain management study. Runoff The amount of rainfall that drains into the surface drainage network to become stream flow; also known as rainfall excess. Storm surge The increases in coastal water levels above the predicted tide level resulting from a range of location dependent factors such as wind and waves, together with any other factors that increase tidal water level. Revised Draft Victorian Floodplain Management Strategy 79

212 Bibliography Australian Building Codes Board 2012, Construction of buildings in flood hazard areas Standard, ABCB, Canberra. Attorney General s Department 2009, Australian Emergency Manual Series Manual 7: Managing the floodplain: a guide to best practice in flood risk management in Australia, Commonwealth of Australia, Canberra. Attorney General s Department 2009, Australian Emergency Manual Series Manual 21 Flood Warning, Commonwealth of Australia, Canberra. Attorney General s Department 2011, National Emergency Risk Assessment Guidelines, Commonwealth of Australia, Canberra. Australian Government Attorney-General s Department 2013, Managing the floodplain: a guide to best practice in flood risk management in Australia, Handbook 7, 2nd edition, Australian Emergency Management Institute, Canberra. Bureau of Meteorology 2001, Arrangements for Flood Warning Services in Victoria, Commonwealth of Australia. Comrie, N 2011, Review of the flood warnings and response, Victorian Government, Melbourne. Council of Australian Governments 2009, National Strategy for Disaster Resilience, Australian Government, Canberra, ag.gov.au/emergencymanagement/pages/ NationalStrategyForDisasterResilience.aspx. Cox, RJ, Shand TD & Blacka MJ 2010, Australian rainfall and runoff revision project: appropriate Safety Criteria for People, Stage 1 report, Engineers Australia, Canberra. Department of Environment and Primary Industries 2013, Improving our waterways: Victorian waterway management strategy, Victorian Government, Melbourne. Department of Environment and Primary Industries 2013, Victorian Climate Change Adaptation Plan, Victorian Government, Melbourne. Department of Natural Resources and Environment 1998, Victoria Flood Management Strategy, Victorian Government, Melbourne. Department of Premier and Cabinet 2013, Victorian Critical Infrastructure Resilience Interim Strategy, Victorian Government, Melbourne. Department of Sustainability and Environment 2012, Victorian Coastal Hazard Guide, Victorian Government, Melbourne. Department of Transport, Planning and Local Infrastructure, Victoria Planning Provisions, planningschemes.dpcd.vic.gov.au/schemes/vpps. Department of Transport, Planning and Local Infrastructure, State Planning Policy Framework, planningschemes/get-information/historicalplanning-information/planning-scheme-historyindex/victoria-planning-provisions. Department of Treasury and Finance 2008, Government policy and guidelines: indemnities and immunities, Victorian Government, Melbourne. Emergency Management Victoria 2013, Emergency Management Manual Victoria, Victorian Government, Melbourne. National Emergency Management Committee 2011, National Strategy for Disaster Resilience, Commonwealth of Australia. Parliament of Victoria 2012, Environment and Natural Resources Committee Inquiry into flood mitigation infrastructure in Victoria, Parliamentary Paper No. 169, Victorian Government, Melbourne. Pilgrim, DH, (ed) 1987, Australian Rainfall & Runoff A Guide to Flood Estimation, Institution of Engineers Australia, Barton, ACT. Shand TD, Cox RJ, Blacka MJ & Smith GP 2011, Australian rainfall and runoff revision Project 10: Appropriate safety criteria for vehicles literature review, Stage 2 report, Engineers Australia, Canberra. Trowbridge J 2011, National disaster insurance review: inquiry into flood insurance and related matters, Victoria Coastal Council 2014, Victorian Coastal Strategy 2014, Victorian Government, Melbourne. Victorian Government 2012, Victorian Emergency Management Reform White Paper, Victorian Government, Melbourne. Victorian Government 2012, Victorian Government s response to the Victorian floods review: improving flood warning systems implementation plan, Victorian Government, Melbourne. Revised Draft Victorian Floodplain Management Strategy 80

213 Legislation Victorian Government 2013, Victorian Climate Change Adaptation Plan, Victorian Government Melbourne. Victorian Government 2013, Victorian Government s response to the Environment and Natural Resources Committee inquiry into flood mitigation infrastructure in Victoria, Victorian Government, Melbourne. Victorian Climate Initiative 2014, Victorian Climate Initiative Annual Report 2013/14, Victorian Climate Initiative, Australia. Victoria State Emergency Service 2012, State Flood Emergency Plan, Victoria State Emergency Service 2012, Management of flooding downstream of dams attachment to Victoria State flood emergency plan, Victorian Water Resources Council 1978, Flood Plain Management in Victoria, VWRC. State of Victoria 1962, Sale of Land Act, State of Victoria 1986, Emergency Management Act, State of Victoria 1989, Water Act, State of Victoria 1989, Planning and Environment Act, State of Victoria 1993, Building Act, State of Victoria 1995, Coastal Management Act, State of Victoria 2005, State Emergency Services Act, State of Victoria 2006, Aboriginal Heritage Act, State of Victoria 2006, Building Regulations, State of Victoria 2013, Emergency Management Act, State of Victoria 2014, Water Bill Exposure Draft, State of Victoria 2014, Water Amendment (Flood Mitigation Bill) Act, Revised Draft Victorian Floodplain Management Strategy 81

214

215 Melbourne Water Principles for Provision of Waterway and Drainage Services for Urban Growth

216 Contents About Melbourne Water 3 Principles for Creating Development Services Schemes 4 Preface 4 (Original) Review Group Members 4 Working Group Members 4 Introduction 5 Melbourne Water 5 Council 5 Development Services Schemes 6 Principles for Creating Development Services Schemes 7 Overview 7 Tests of the Principles 7 Design Standards for Development Services Schemes 7 The Principles 8 Table 1: Summarising the Principles 13 Principles for Creating Redevelopment Services Schemes 15 Introduction 15 The Principles 15 Table 2: Summarising the Principles 19 Principles for Funding of Drainage Works Outside of Development Services Schemes 21 Introduction 21 The Principles 21 Table 3: Summarising the Principles 23 Principles for Stormwater Quality Offsets 24 Introduction 24 The Principles 24 Table 4: Summarising the Principles 27

217 About Melbourne Water Melbourne Water is owned by the Victorian Government. We manage Melbourne s water supply catchments, remove and treat most of Melbourne s sewage, and manage rivers and creeks and major drainage systems throughout the Port Phillip and Westernport region. Under the Victorian Government s Our Water Our Future action plan, our boundary now extends from high up in the Yarra Ranges across to Ballan in the west, and from the Mornington Peninsula and Phillip Island north to Lancefield, covering an area of approximately 13,000 square kilometres. We are a significant business, responsible for managing $8.4 billion of natural and built assets. Our annual operating revenue of more than $500 million is earned from water supply, sewage treatment and a catchment rate levied for waterways, flood and drainage management. This is used to fund our operations and infrastructure projects including water, sewerage and flood protection, as well as projects to improve and protect the health of Melbourne s rivers and creeks. We are committed to decision-making based on economic, social and environmental considerations. An independent Board of Directors is responsible for the governance of Melbourne Water. The responsible Minister is the Minister for Water. Our people have diverse skills and expertise, and range from environmental scientists to engineers and research and technology specialists, and we place a high priority on building strong partnerships and relationships in the government, industry and community. 3

218 Melbourne Water Principles for Provision of Waterway and Drainage Services for Urban Growth Principles for Creating Development Services Schemes Preface A specially appointed Review Group of experienced people representing the development industry, local government and Melbourne Water established a set of principles to guide the preparation of development services schemes (formerly known as greenfield drainage schemes), which were adopted as Melbourne Water policy in September A number of matters raised during the consultation with industry have been progressed through a joint Working Group. The Working Group has been meeting regularly (about every three months) since April 2004 to discuss and address various issues relating to development services schemes. In late 2005, the Working Group agreed that it was appropriate to update the original principles and to also incorporate the principles relating to Redevelopment Services Schemes, Works Outside of Development Services Schemes, and Stormwater Quality Offsets into a combined Melbourne Water Principles for Provision of Waterway and Drainage Services for Urban Growth document. On 1 January 2004, the Essential Services Commission (ESC) became responsible for the economic regulation of the Victorian water industry. This responsibility includes setting prices and service standards for regulated services provided by the State s water businesses. The ESC has endorsed the development services scheme approach and the manner in which developer charges are calculated whereby the cost of all capital expenditure expected over the life of the scheme is recovered from developers in the form of developer contributions under the Water Act 1989 (Vic) (the Water Act). (Original) Review Group Members The members of the Review Committee were: Mark Bartley, Urban Development Institute of Australia Chris Betts, Housing Industry Association Bert Dennis, Urban Development Institute of Australia Mike Ellis, Municipal Association of Victoria Simon Holloway, Municipal Association of Victoria John Maxwell, Association of Land Development Engineers Fiona Nield, Housing Industry Association Jim O Donahue, Association of Land Development Engineers Ross Young, (Chair) Melbourne Water Working Group Members Michael Brown, Melbourne Water Chris Chesterfield, Melbourne Water Y.C. Chia, (Chair) Melbourne Water Graham Daff, Melbourne Water Mike Ellis, Municipal Association of Victoria Eleanor Jacobs, Municipal Association of Victoria Simon Marchington, Melbourne Water John Maxwell, Association of Land Development Engineers Chris McNeill, Urban Development Institute of Australia Janine Nechwatal, Housing Industry Association David Norman, Melbourne Water Jim O Donahue, Association of Land Development Engineers Ken O Neill, Melbourne Water John Prentice, Association of Land Development Engineers David Richardson, Municipal Association of Victoria 4

219 Introduction Melbourne Water established a Review Group in March 2003 to review the basic principles that underpin our approach to the creation of development services schemes (formerly drainage schemes). The original document consisted of: An endorsed set of 16 principles to guide the preparation and review of development services schemes An outline of Melbourne Water and local government drainage responsibilities A summary description of development services scheme and development corridor charging models. This new document consists of a set of revised principles endorsed by the Working Group and industry stakeholder association members. Melbourne Water Melbourne Water is responsible for regional drainage, flood plain and waterway management, and for contributing to the protection and improvement of waterway health across greater Melbourne. These responsibilities are managed with a focus on sustainable social, environmental and economic outcomes. In relation to regional drainage, flood plain and waterway management, Melbourne Water is a: Water Corporation and an Authority under the Water Act, with waterway management, regional drainage and floodplain management functions under Divisions 2, 3 and 4 of Part 10 of the Water Act. These functions include: ensuring that adequate drainage and flood protection standards for development are achieved; and ensuring that the bed and banks of waterways are protected and enhanced. Referral authority under the Planning and Environment Act 1987 with the ability to specify conditions pertaining to the use or development of a property. Development services schemes are prepared to plan the infrastructure required to ensure new urban development meets appropriate standards for flood protection, water quality, waterway health and amenity. Infrastructure requirements are costed and used to establish contributions under the Water Act that will apply to developers to fund the provision of infrastructure. Drainage infrastructure is planned to service catchments downstream of the top 0.4 hectare in a greenfield development catchment. Melbourne Water owns and maintains constructed assets downstream of the 60-hectare limit. The remaining assets are transferred to local councils following an agreed process. Council Councils are the responsible authorities for planning decisions made with reference to planning schemes that control land use and development. Planning schemes contain State and local planning policies, zones and overlays and other provisions that affect how land can be used and developed. Councils are also responsible for managing local drainage infrastructure in catchments of less than 60 hectares, including ownership and maintenance of drainage assets. 5

220 Melbourne Water Principles for Provision of Waterway and Drainage Services for Urban Growth Principles for Creating Development Services Schemes Development Services Schemes (DSS) The planning and provision of new infrastructure to support greenfield development within Melbourne Water s operational boundary (waterway management district) is usually managed using a development services scheme. A development services scheme comprises a drainage strategy for an area together with a pricing arrangement that allows Melbourne Water to require developers to contribute to the cost of the construction of works by Melbourne Water in connection with a development. Planning permit referrals received from councils under the Subdivision and Planning and Environment Acts are one trigger for this process. The strategy consists of functional designs for Melbourne Water (regional) and local council drainage assets, including works such as pipelines, overland flow paths, retarding basins, waterways, wetlands and gross pollution traps and identification of land to be set aside for these purposes. The strategy ensures that planning for urban development is conducted on a catchment basis and meets appropriate standards for flood protection and environmental performance, including protection and enhancement of waterway and biodiversity values. The infrastructure within the scheme is funded by financial contributions from developers or landowners when development occurs, with all developable properties contributing on the basis of land area and land zoning. Income from developer contributions is designed to equal planned expenditure of drainage infrastructure over the expected life of a development services scheme (typically 25 years). Currently, there are in excess of 80 active development services schemes. Priority is given to preparing schemes in areas where new development activity is most concentrated. The aim is to ensure a scheme is prepared within three years of the start of a consistent pattern of significant subdivisional activity. Annual financial reviews and engineering reviews at least once every five years, are required to ensure that expenditure on drainage growth infrastructure is matched by contributions. 6

221 Principles for Creating Development Services Schemes Overview Development charges serve two main purposes: Provide price signals regarding the cost of provision of drainage infrastructure for development. Reasonable development charges should reflect the cost of servicing developments including identifiable upstream and downstream effects, minimise cross subsidies and signal the relative costs of providing drainage infrastructure for growth Provide an equitable means of sharing costs of drainage infrastructure required for urban development. The principles outlined in this document, together with Melbourne Water s legislative powers and principles adopted by the Council of Australian Governments (COAG) for Water Policy, are designed to provide an integrated solution to drainage, waterway and stormwater quality works including: Adoption of an integrated catchment approach to stormwater management User based pricing, full cost recovery and removal of cross subsidies that are not consistent with efficient and effective services Environmental requirements based on the best available scientific information Protection of waterway health and biodiversity values. The principles are designed to meet the tests of equity, transparency and nexus, while facilitating development in a way that leads to positive social, economic and environmental outcomes. Tests of the Principles In order to assess whether a development services scheme accords with the principles set out in this document, the scheme design would be reviewed and the following tests applied to determine that: There is a reasonable basis for determination of the scheme boundary There is a nexus between contributions and the costs of the infrastructure required and that common costs are apportioned in an equitable manner to achieve a reasonable development contribution amount. Design Standards for Development Services Schemes A common set of hydraulic and environmental performance criteria are incorporated into the design of development services schemes. They are: All new developments will be provided with 1-in-100 year flood protection consistent with ResCode requirement The minor drainage system shall have a capacity to cater for a 1-in-5 year storm event Water quality treatment to Best Practice * (currently 45% reduction in total nitrogen and phosphorous, 80% reduction in total suspended solids) Protection of the environmental, social (including heritage) and economic values of waterways. The above criteria form the basis of the development services scheme strategy prepared for the catchment. * As defined in Urban Stormwater: Best Practice Environmental Management Guidelines (Victorian Stormwater Committee 1999). 7

222 Melbourne Water Principles for Provision of Waterway and Drainage Services for Urban Growth Principles for Creating Development Services Schemes The Principles 1. There shall be no formal limit on the size of the scheme area. The appropriateness of size will vary from scheme to scheme and is governed by nexus between contributing properties and infrastructure provision. This is likely to be closely related to the drainage characteristics of the land. The minimum sizing of the scheme should achieve a direct relationship between land in the scheme and proposed drainage works, and should have regard to practical planning and administrative requirements. 2. The boundary of a scheme will be determined by the drainage characteristics of the land. The best boundary for a scheme is the natural drainage topography of the sub-catchment itself. This consists of ridgelines which direct run-off into separate catchments on either side of the ridge and waterways that receive stormwater run-off. Selecting the natural boundary may be rendered impractical by pre-existing modifications to the topography of the land. These include: Railway lines Raised roads Levee banks Other engineering works that redirect drainage flows. The modifications described above form constructed boundaries that may be adopted as a logical alternative to natural boundaries to determine the scheme boundary. There are also other influences on boundary lines including urban development zones and property titles straddling catchment boundaries. 3. Schemes will be planned to service all developable lots. Development services schemes will be planned to service all developable lots within the scheme. This usually involves planning infrastructure down to 0.4 hectare lots. The ownership and ongoing maintenance of drainage assets in catchments of less than 60 hectares within development services schemes will generally be transferred to local councils. 4. Schemes should propose infrastructure to service development that is optimal in terms of cost and performance. Development services schemes identify the infrastructure required to adequately service land capable of being developed. The scheme consists of an infrastructure plan, which takes into account environmental considerations and an estimate of the cost of works to control the quality and quantity of stormwater run-off. The design should propose works that are optimal in terms of cost and performance, while protecting environmental and other waterway values. Development services schemes may include mandatory water sensitive urban design requirements applicable to all developments rather than provision of scheme financed infrastructure. 8

223 5. Infrastructure benefits common to more than one scheme will have the cost apportioned. The cost of infrastructure contained within and specific to a single scheme is costed entirely to that scheme. The cost of infrastructure servicing multiple schemes will need to be transparently apportioned based on capacity share. This infrastructure may be sited in different locations but will be apportioned according to the benefits derived by the schemes. For example, a retarding basin may be located: Downstream of the scheme it services Within one of the schemes for reasons of cost effectiveness, but having the effect of enabling more than one scheme to develop. 6. All landowners will receive an equivalent level of service. Scheme infrastructure will be designed to service all developable lots within the scheme down to 0.4 hectare lots and provide a single drainage outlet to each lot regardless of size. Owners of large lots will receive an equivalent level of service provided to smaller lots with appropriate drainage works based on engineering judgement. Appropriate works may include: Additional drainage lines Upsizing of the stormwater system to enable additional connection points Additional infrastructure to low points to facilitate further connection points. 7. Infrastructure designed to accommodate run-off from non-developable land within the scheme boundary will be funded by development contributions. Works may be required to protect new developments against runoff from non-developable land. Non-developable land includes: Existing reserves and conservation areas Flood plains Existing roads (including sealed, gravel and paper roads) Other land types not zoned for development. Protection works will generally be funded by the development services scheme. Should the non-developable land subsequently be developed, new infrastructure and scheme charges may apply. If plans for future roads are presented early enough the required drainage design and related run-off will be accommodated by the development services scheme. Otherwise the organisation creating the new road will be required to pay the relevant contributions and for additional drainage works above the scheme proposal. If an existing road is widened after the development services scheme has been implemented, where the road widening was not communicated to Melbourne Water prior to implementing the scheme, the responsible road authority is accountable for the drainage works through the road widening but is not required to contribute for the area of the road widening. 9

224 Melbourne Water Principles for Provision of Waterway and Drainage Services for Urban Growth Principles for Creating Development Services Schemes Paper roads are public road reservations that are not constructed at the time of the scheme preparation. Paper roads are exempt from contributing to the development services scheme even if they are developed as constructed roads. If paper road areas are purchased for development purposes then the area will be subject to paying contributions to the scheme. Contributions are always required from the developer for all subdivisional roads. No contributions are required for existing roads. 8. Scheme infrastructure to service existing developed land within the scheme boundary will be funded by Melbourne Water or Council. Melbourne Water or in some cases the local council (via private scheme) will meet the costs of servicing existing development within a development services scheme. These areas have either already paid contributions, or are deemed to have contributed to drainage works under arrangements that preceded the establishment of the development services scheme. This is based on the assumption that the density of development is not changing. If the density is changing then a contribution may apply. 9. Infrastructure to service existing and future development external to the scheme will not be funded by development contributions from within the scheme. Where upstream flows within the natural catchment, but outside the scheme boundary, have been modified by existing urban development (eg. rural townships) or will be modified by expected future urban development, upsizing works within the development services scheme to cater for the modified flows will not be funded by developer contributions to that scheme. Melbourne Water will participate in the scheme and contribute to the funding of the drainage infrastructure. This contribution will be recovered when the land outside the scheme is ultimately developed. 10. Environmental works downstream of development services schemes will be funded by schemes where upstream development is the cause of the problem. Costs of works downstream of development services schemes that are attributable to altered flows and waterway pollution from development within the upstream development services scheme will be included in the scheme. The cost of such downstream works will be incorporated into individual contributing development services schemes based on analysis of relative share of the problem caused by each scheme. 11. Melbourne Water or local councils will meet the cost of improved service standards for existing development within a scheme. Melbourne Water or the local council (via private scheme) will meet the additional costs incurred in the scheme to increase the standard of flood protection, water quality or to enhance waterway values for existing development to an acceptable level in their respective drainage areas. Works to improve existing standards may be undertaken concurrently with growth works with costs shared between Melbourne Water (rates funded) and developments (growth). The same arrangement would apply to councils. 10

225 12. Contribution rates will be structured to balance income and expenditure over the life of a development services scheme. Infrastructure within the scheme is funded from contributions received from landowners within the scheme area when they develop properties. The contribution amount is based on the area of the development and the rate, quantity and quality of stormwater run-off. Financial modelling will be undertaken upon the establishment of each new scheme to calculate the contribution rate that balances income and expenditure over the life of the scheme after adjustment for the time value of money. Adjusting for the time value of money involves calculating the costs of the scheme in today s dollars and discounting at an appropriate rate. A contribution rate per hectare is determined which effectively brings the Net Present Value of the combined income and expenditure stream to a zero balance. 13. A robust consultation process will govern the creation of development services schemes. To ensure interested parties are kept informed and have an opportunity to contribute to the creation of development services schemes Melbourne Water will: Inform all interested parties of the proposed scheme area at the commencement of the scheme design Exhibit and forward draft scheme proposals to interested parties for comment Communicate with respondents and amend scheme details where appropriate Submit final draft to interested parties and provide an opportunity for objections which will be considered by Melbourne Water Advise interested parties of the adoption of the scheme. Interested parties include landowners within a scheme or potentially affected by a scheme, development industry, and community interest groups (e.g. Friends Group). Should there be a difference of opinion on the planned scheme, the following dispute resolution process will apply: An attempt to reach agreement between the parties by negotiation If unsuccessful, present objection to Melbourne Water s Waterways Group General Manager for consideration If the outcome is not acceptable to the objector, the proposed scheme would be referred to an independent review panel. The panel may consist of a lawyer, town planner and civil engineer During the dispute resolution process Melbourne Water will continue to accept development contributions and facilitate ongoing development activity. A developer who is required by Melbourne Water to make a contribution to a development services scheme under the relevant provisions of the Water Act may object to Melbourne Water in accordance with the procedure set out in section 271 of the Water Act. 11

226 Melbourne Water Principles for Provision of Waterway and Drainage Services for Urban Growth Principles for Creating Development Services Schemes 14. Development services schemes will be adjusted for innovation works that benefit the scheme. Development services scheme charges will be reduced if developers provide innovative solutions that benefit the scheme and result in significant savings to scheme finances. Melbourne Water will reward for innovations that financially benefit the scheme. The level of reward will be based on the particular circumstances relating to each innovation. The reward or reduction in scheme contribution will be based on the saving to the scheme; the overall financial benefit of the innovation, and other benefits derived by the developer. Melbourne Water will reduce scheme water quality contributions according to the percentage of best practice (for Total Nitrogen) that is achieved within the development. 15. Development services schemes will have annual financial reviews and engineering reviews at least once every five years. Development services schemes require financial, engineering and environmental reviews on a regular basis to ensure costs are neither over nor under recovered and up-to-date requirements are included in the technical provision. Financial reviews will occur on a yearly basis Engineering reviews (hydraulic and water quality) will occur progressively as the circumstances of the scheme alter with a maximum five-year interval between reviews. Two months notice will apply for rate increases. Decreases or no alterations to existing rates will apply immediately. The results of reviews will be communicated via Melbourne Water s Land Development Manual website and via to developers consultants. For engineering reviews, consultation processes as per Principle 13 will operate for affected landowners. All parties in receipt of a current offer will be contacted. 16. Development services schemes will include land acquisition costs based on the undeveloped broad acre value. Determining applicable contribution rates for new schemes involves estimating the cost of land to be purchased for scheme purposes and incorporating these estimates into the pricing model. For a consistent and predictable approach to the valuation of land for scheme pricing purposes, Melbourne Water will: Include acquisition costs in development services schemes where the land is otherwise deemed to be developable Value the land based on the undeveloped broad acre land value, recognising the underlying zoning and any infrastructure works completed at the date of inspection by a land valuer. When the time comes to purchase the land, the compensation paid to the landowner is determined using State Government issued valuation guidelines. 12

227 Table 1: Summarising the Principles Principle 1. There shall be no formal limit on the size of the scheme area. 2. The boundary of a scheme will be determined by the drainage characteristics of the land. 3. Schemes will be planned to service all developable lots. 4. Schemes should propose infrastructure to service development that is optimal in terms of cost and performance. 5. Infrastructure benefits common to more than one scheme will have the cost apportioned. 6. All landowners will receive an equivalent level of service. 7. Infrastructure designed to accommodate run-off from non-developable land within the scheme boundary will be funded by development contributions. 8. Scheme infrastructure to service existing developed land within the scheme will not be funded by development contributions. 9. Infrastructure to service existing and future development external to the scheme will not be funded by development contributions from within the scheme. Comment The minimum sizing of the scheme should achieve a direct relationship between land in the scheme and proposed drainage works and should have regard to practical planning and administrative requirements. The best boundary for a scheme is the natural drainage topography of the sub-catchment itself. Selecting the natural boundary may be rendered impractical by pre-existing modifications to the topography of the land. The modifications described above form constructed boundaries that may be adopted as a logical alternative to natural boundaries to determine the scheme boundary. There are other minor influences on boundary lines (eg. property titles straddling catchment boundaries). Melbourne Water will plan development services schemes to service all developable lots within the scheme. This involves planning infrastructure down to 0.4 hectare lots. The design should propose works that are optimal in terms of cost and performance, while protecting environmental and other waterway values. The cost of infrastructure servicing multiple schemes will be apportioned based on capacity share. This infrastructure may be sited in different locations but will be apportioned according to the benefits derived by the catchments. Owners of large lots will receive an equivalent level of service provided to smaller lots with appropriate drainage works based on engineering judgement. Non-developable land includes: Existing reserves and conservation areas Flood plains Existing roads Other land types not zoned for development. Melbourne Water or the council will meet costs due to existing development. Where upstream flows within the natural catchment but outside the scheme boundary have been modified by existing urban development (eg. rural townships) or will be modified by expected future urban development, upsizing works within the development services scheme to cater for the modified flows will not be funded by developer contributions to that scheme. 13

228 Melbourne Water Principles for Provision of Waterway and Drainage Services for Urban Growth Principles for Creating Development Services Schemes Principle 10. Environmental works downstream of development services schemes will be funded by schemes where upstream development is the cause of the problem. 11. Melbourne Water or local councils will meet the cost of improved flood protection for existing development. 12. Contribution rates will be structured to balance income and expenditure over the life of a development services scheme. 13. A robust consultation process will govern the creation of development services schemes. 14. Development services schemes will be adjusted for innovation works that benefit the scheme. 15. Development services schemes will have annual financial reviews and engineering reviews at least once every five years. 16. Development services schemes will include land acquisition costs based on the undeveloped broad acre value. Comment Costs of works downstream of development services schemes that are attributable to altered flows and waterway pollution from development within the upstream development services scheme will be included in the development services scheme. Melbourne Water or the local councils will meet the additional costs incurred in the scheme to increase the standard of drainage protection, water quality and waterway values to existing development to an acceptable level. Financial modelling will be undertaken upon the establishment of each new development services scheme to calculate the contribution rate that balances income and expenditure over the life of the scheme after adjustment for the time value of money. Melbourne Water will consult with industry, landowners and other interested parties prior to finalising and establishing new development services schemes, including possible mediation and independent review. Melbourne Water will reward innovation by developers that financially benefit the scheme. The reward or reduction in scheme contribution will be based on the saving to the scheme; the overall financial benefit of the innovation, and benefit derived by the developer. Schemes will have annual financial reviews to ensure the contribution rate reflects actual and forecast income and expenditure cash flows. Schemes will have engineering and environmental reviews at least once every five years to ensure current standards are being met. Two months notice will apply for rate increases. Decreases or no alterations to existing rates will apply immediately. For a consistent and predictable approach to land valuation for scheme pricing purposes Melbourne Water will: Include acquisition costs in schemes where the land is otherwise deemed to be developable Value the land based on the undeveloped broad acre land value, recognising the underlying zoning and infrastructure works completed at the date of inspection by a land valuer. 14

229 Principles for Creating Redevelopment Services Schemes Introduction Impacts from redevelopment are most significant in established urban areas designed with no consideration for overland flows associated with larger storm events when the capacity of the constructed drainage system is exceeded. The provision of new drainage infrastructure to support redevelopment of established areas within Melbourne Water s operational boundary is being managed with the staged introduction of redevelopment services schemes. A redevelopment services scheme (RSS) comprises a drainage strategy for an existing area together with a pricing arrangement that allows Melbourne Water to require developers to contribute to the cost of the construction of drainage works by Melbourne Water in connection with the redevelopment. Planning permit referrals received from councils under the Subdivision and Planning and Environment Acts are one trigger for this process. The strategy consists of functional designs for additional Melbourne Water assets that are required to mitigate the impacts of redevelopment of an established urban area. The strategy ensures that planning for urban redevelopment is conducted on a catchment basis and that appropriate drainage infrastructure is provided so that the existing level of drainage service is not compromised. The drainage infrastructure within the scheme is funded by financial contributions from land development when development occurs, with all developable properties contributing on the basis of the average change in hard surface area. Income is designed to equal planned expenditure over the expected life of a scheme and is calculated on a rolling 25-year period. Currently, there are 5 active redevelopment schemes with the investigation of 30 new schemes up to Priority is given to preparing schemes in areas where redevelopment activity is most concentrated. The aim is to ensure redevelopment schemes cover the established areas of Melbourne within ten years. The Principles 1. Redevelopment within a catchment shall not result in a reduction to the existing level of drainage service. The existing level of drainage service relates to both the frequency of flooding instances as well as to the existing 100-year ARI flood level and extent. Redevelopment Services Scheme (RSS) infrastructure is sized to ensure that the 100-year ARI flood level, extent and frequency are not increased due to redevelopment. This ensures that the level of drainage service for smaller events is not diminished, as the magnitude of peak flow change is greatest for the 100-year event. 2. A robust consultation process will govern the creation of Redevelopment Services Schemes. Council and landowners are key stakeholders in the preparation of RSS. At the commencement of each RSS investigation, Council input is sought on the location and density of redevelopment that is likely to occur in their municipality, which is then included in the modelling. At the completion of the RSS investigation, Council is asked to provide comments on the overall RSS and to give in principle agreement to the proposed alignments selected for any RSS works where they impact on Council assets such as roads and reserves. Comments on the RSS are sought from the community and interested parties through advertisements in local papers. Unlike Development Services Schemes, it is not feasible to notify potential developers individually. 15

230 Melbourne Water Principles for Provision of Waterway and Drainage Services for Urban Growth Principles for Creating Redevelopment Services Schemes Industry bodies are also notified and their comments sought on each new RSS. A developer or landowner who is required by Melbourne Water to make a contribution to a RSS under the relevant provisions of the Water Act may object to Melbourne Water in accordance with the procedure set out in section 271 of the Water Act. 3. Properties redeveloping within a catchment will be required to contribute to the scheme or required to mitigate the impacts of redevelopment on site. The adverse effects from increases in hard surfaces due to redevelopment of an individual site can be mitigated on site. This is generally through the combination of on-site detention and Water Sensitive Urban Design (WSUD). Catchment-wide adoption of on-site detention and WSUD would be required as a RSS will not be viable unless the majority of the catchment is contributing to the RSS. A mechanism to ensure that on-site detention and WSUD is adopted across a catchment does not currently exist. Whether a scheme is appropriate or on site works are more viable for a given catchment will be based on an assessment of the costs of providing Melbourne Water infrastructure and feedback received through consultation undertaken with council, landowners and industry bodies. 4. The RSS contribution will generally apply to redevelopment of existing residential areas within the catchment irrespective of the existing site coverage. The existing drainage system was provided and paid for, based on expected land use and the hard surface area assumed for that land use. For residential areas, the assumed hard surface area is dependant on the lot size. For a given residential lot size, the actual hard surface area will vary. However, the charge is based on the average hard surface area for that residential lot size. Accordingly, the existing hard surface area on a given residential lot will not alter the assessment of the RSS infrastructure required and the contribution to be paid. 5. Existing Industrial and Commercial areas being redeveloped will generally not be required to contribute to the RSS unless an impact to the existing level of drainage service can be determined. When the existing drainage system was provided, a certain level of hard surface area was assumed based on expected land use. For industrial and commercial areas this value was, in general, fairly high. Redevelopment of industrial and commercial areas does not commonly result in increased hard surface area beyond what the existing drainage system was designed for, even if the land use changes to residential. 6. Greenfield contribution rates for sites within RSS catchments will be calculated at the time of scheme implementation and included in the RSS contribution rate. Any greenfield sites in RSS areas will be identified as part of the RSS investigation. If no drainage contributions have previously been paid for a particular site then charges will apply to develop the site from greenfield to ultimate conditions based on the average change in hard surface area. This allows a greenfield site, in an existing urban area, to develop in a number of stages without the need to alter the RSS. 16

231 7. RSS are catchment based and all residential developments will contribute at the same rate. RSS are generally sized based on drainage catchments for Melbourne Water infrastructure. All properties within a catchment contribute to the increased runoff at the outlet based on the average change in hard surface area. The average change in hard surface area depends on the existing size of the lot to be subdivided and the number of new lots created. Generally, RSS works will commence at the downstream end of a catchment and proceed upstream as contributions are collected. As redevelopment is likely to occur catchment wide rather than concentrated in one locality the impact on the existing level of drainage service will be greatest at the most downstream point. Given this, all redevelopment in a catchment will benefit from the downstream works and will be required to contribute to the works. 8. Properties with existing buildings that pre-date the RSS will not be required to contribute to the RSS. Existing dwellings that were occupied prior to the introduction of the RSS do not have to contribute. Documentation in the form of a Certificate of Occupancy issued by the relevant council or other documentation to the satisfaction of Melbourne Water that demonstrates the building has been occupied prior to the commencement of the RSS will be required. 9. RSS generally cover works on Melbourne Water assets i.e. catchments greater than 60 hectares. RSS are specifically designed to deal with the impact of redevelopment on the level of service provided by Melbourne Water infrastructure. Depending on circumstances it may be necessary for Melbourne Water to do works on Council infrastructure. In these circumstances, Melbourne Water will seek and obtain agreement from Council on any works that will become the responsibility of Council before RSS approval. As for Development Services Schemes, Melbourne Water will collect the contributions required, construct the works and then hand over the completed asset to Council for ownership and maintenance responsibility. 10. When an impact to a waterway is directly attributed to redevelopment, RSS shall also apply to waterway catchments. If an investigation determines that redevelopment may increase flooding in a downstream waterway, then the RSS may propose mitigation works in the waterway. Any proposed works on waterways must take account of the environmental and social values of that waterway as outlined in the Port Phillip and Westernport Regional River Health Strategy. 11. No Water Quality works are included in RSS. Achievement of water quality objectives on-site will be required in accordance with the Sustainable Neighbourhoods (Clause 56) provision. Further details may be obtained from Melbourne Water s Land Development Manual. No contribution rates for water quality are included in RSS charges. 12. RSS will operate until the expected level of redevelopment has been reached. RSS are long term planning tools that identify all works required to facilitate redevelopment using development locations (e.g. activity centres, along transport routes and infill) identified in the Government s Melbourne 2030 planning policy document. 17

232 Melbourne Water Principles for Provision of Waterway and Drainage Services for Urban Growth Principles for Creating Redevelopment Services Schemes While Melbourne 2030 provides direction for development up until the year 2030 the full impact on the Melbourne Water drainage system will occur some time after that in the majority of catchments. The RSS will operate until the expected level of development is reached and all works identified in the scheme have been constructed. 13. RSS are financially reviewed each year and an engineering review is undertaken at least once every five years. As per Development Services Schemes, RSS will be financially reviewed annually and an engineering review will be done at least once every five years. The financial review will adjust the scheme rate based on the actual level of development and constructed works compared to the predicted level of development and works estimated at the start of the RSS. The engineering review will re-examine all aspects of the engineering design and update as necessary including undertaking any consultation required. 14. Melbourne Water will fund improvements to the existing drainage system to meet current standards. Improvements to the existing level of drainage service are the responsibility of Melbourne Water. Enhancement of the existing waterway values is also the responsibility of Melbourne Water. The RSS will only fund the cost of works to accommodate increased run-off from future development so that the existing level of service is not diminished. Developers are not expected to contribute to the cost of fixing existing problems. 15. An annual capital program will be prepared and works will be undertaken on a priority basis from all RSS projects. Melbourne Water undertakes long-term capital planning with prioritisation of each scheme s work sections based on the following: Allocation of funding within the 20-year capital plan and the 3-year Water Plan Rate of redevelopment within each catchment Estimated cost for the downstream work sections in all RSS Effect on the individual scheme rate Consideration of the Asset Renewal program to ensure any cost benefit for undertaking combined works can be captured Consideration of the Flood Mitigation program to ensure any cost benefit for undertaking combined works can be captured. 16. Melbourne Water will generally undertake RSS works from the downstream end of the catchment to the upstream end of the catchment. If a development contains RSS works, the works could be constructed in conjunction with development, even though it may be out of sequence. Works will be undertaken from the downstream end of the catchment first as this ensures that all properties in the catchment receive a benefit from the works. Works may be done out of sequence when a development is located adjacent to proposed RSS works. Requiring developers to undertake these works will depend on the financial status of the RSS and the relevant benefit of undertaking the works out of sequence. 18

233 Table 2: Summarising the Principles Principle 1. Redevelopment within a catchment shall not result in a reduction to the existing level of drainage service. 2. A robust consultation process will govern the creation of Redevelopment Services Schemes. 3. Properties redeveloping within a catchment will be required to contribute to the scheme or required to mitigate the impacts of redevelopment on site. 4. The RSS contribution will generally apply to redevelopment of existing residential areas within the catchment irrespective of the existing site coverage. 5. Existing Industrial and Commercial areas being redeveloped will generally not be required to contribute to the RSS unless an impact to the existing level of drainage service can be determined. 6. Greenfield contribution rates for sites within RSS catchments will be calculated at the time of scheme implementation and included in the RSS contribution rate. 7. RSS are catchment based and all residential developments will contribute at the same rate. 8. Properties with existing buildings that pre-date the RSS will not be required to contribute to the RSS. 9. RSS generally cover works on Melbourne Water assets i.e. catchments greater than 60ha. Comment RSS infrastructure is sized to ensure that the 100-year ARI flood level, extent and frequency are not increased due to redevelopment Council input is sought on the location and density of redevelopment that is likely to occur in their municipality. Comments from the community and interested parties are sought through advertisements in local papers. Whether a scheme is appropriate or on site works are more viable for a given catchment will be based on an assessment of the costs of providing Melbourne Water infrastructure and feedback received through consultation undertaken with council, landowners and industry bodies. The existing drainage system was provided and paid for, based on expected land use and the hard surface area assumed for that land use. Therefore the existing hard surface area on a given residential lot will not alter the assessment of the RSS infrastructure required and the contribution to be paid. Redevelopment of industrial and commercial areas does not commonly result in increased hard surface area beyond what the existing drainage system was designed for, even if the land use changes to residential. Any greenfield sites in RSS areas will be identified as part of the RSS investigation. If no drainage contributions have previously been paid for a particular site then charges will apply to develop the site from greenfield to ultimate conditions based on the average change in hard surface area. All properties within a catchment contribute to the increased runoff at the outlet based on the average change in hard surface area. The average change in hard surface area depends on the existing size of the lot to be subdivided and the number of new lots created. For contributions to be waived, documentation in the form of a Certificate of Occupancy or equivalent issued by the relevant council that demonstrates the building has been occupied prior to the commencement of the RSS will be required. RSS are specifically designed to deal with the impact of redevelopment on the level of service provided by Melbourne Water infrastructure. Melbourne Water will seek and obtain agreement from Council on any works that will become the responsibility of Council. 19

234 Melbourne Water Principles for Provision of Waterway and Drainage Services for Urban Growth Principles for Creating Redevelopment Services Schemes Principle 10. When an impact to a waterway is directly attributed to redevelopment, RSS shall also apply to waterway catchments. 11. No Water Quality works are included in RSS. 12. RSS will operate until the expected level of redevelopment has been reached. 13. RSS are financially reviewed each year and an engineering review is undertaken at least once every five years. 14. Melbourne Water will fund improvements to the existing drainage system to meet current standards. 15. An annual capital program will be prepared and works will be undertaken on a priority basis from all RSS projects. 16. Melbourne Water will generally undertake RSS works from the downstream end of the catchment to the upstream end of the catchment. If a development contains RSS works, the works could be constructed in conjunction with development, even though it may be out of sequence. Comment If an investigation determines that redevelopment may increase flooding in a downstream waterway, then the RSS may propose mitigation works in the waterway. Any proposed works on waterways must take account of the environmental and social values of that waterway as outlined in the Port Phillip and Westernport Regional River Health Strategy. Achievement of water quality objectives on-site will be required in accordance with the Sustainable Neighbourhoods (Clause 56) provision. No contribution rates for water quality are included in RSS charges. The RSS will operate until the expected level of development is reached and all works identified in the scheme have been constructed. RSS will be financially reviewed annually and an engineering review will be done at least once every five years. The financial review will adjust the scheme rate based on the actual level of development and constructed works. The RSS will only fund the cost of works to accommodate increased run-off from future development so that the existing level of service is not diminished. Developers are not expected to contribute to the cost of fixing existing problems. Prioritisation of works for each scheme is based on: Allocation of funding within the 20-year capital plan and the 3-year Water Plan; Rate of redevelopment within each catchment; Estimated cost for the downstream work sections in all RSS; Effect on the individual scheme rate; Consideration of the Asset Renewal program; Consideration of the Flood Mitigation program. Works may be done out of sequence when a development is located adjacent to proposed RSS works. 20

235 Principles for Funding of Drainage Works Outside of Development Services Schemes Introduction In the past, the cost of providing infrastructure to service growth outside of development services schemes was funded from Corridor contributions. Development corridor contributions were based on larger planning areas (not necessarily based on a drainage catchment) and had been in place since Development corridor contributions only considered Melbourne Water assets, with the developer providing local drainage and water quality improvement works. Development corridor contributions have now been phased out in favour of development and redevelopment services schemes. With the discontinuation of Melbourne Water Corridor Area and associated charges, Melbourne Water no longer will be collecting contributions to fund the construction of Melbourne Water infrastructure in development areas outside of schemes. As discussed above in relation to Development Services Schemes and Redevelopment Services Schemes, the Water Act entitles Melbourne Water to require an owner of property in its waterway management district to contribute to the cost of the construction of drainage works. A developer or landowner who is required by Melbourne Water to make a contribution to the cost of the construction of drainage works under the relevant provisions of the Water Act may object to Melbourne Water in accordance with the procedure set out in section 271 of the Water Act. Therefore principles are required for the funding of works outside schemes, consistent with the principles developed for Development Services Schemes and Redevelopment Services Schemes. Each development however will be assessed on a case-by-case basis. The Principles 1. The Developer will be required to contribute to water quality treatment works as a part of the development. Developers will be required to fund and construct on site water quality treatment to meet Best Practice Objectives for the removal of litter, total suspended solids, total nitrogen and total phosphorus. 2. The Developer will be required to fund the infrastructure necessary to cater for upstream rural flows. Existing conditions of a site will need to be considered in the development of any property. Existing conditions may include drainage lines conveying upstream rural flow. It is considered reasonable that a developer should fund works to cater for existing conditions on their property. 3. Melbourne Water will fund the upsizing of infrastructure to cater for upstream-developed flows from catchment areas larger than 60 hectares. In the case where a development has occurred upstream of a developing property and the discharge through the developing property is increased, it is reasonable that the developer should not pay for upsizing of infrastructure on their developing property if the catchment area is larger than 60 hectares. Melbourne Water will fund the upsizing of such infrastructure required to cater for upstream urban flows and the developer will be required to fund an amount equivalent to what would be required to construct infrastructure to cater for rural flows. Upsizing of infrastructure on the developing property to cater for the property s internal subdivisional developed flows will be funded by the developer. 21

236 Melbourne Water Principles for Provision of Waterway and Drainage Services for Urban Growth Principles for Funding of Drainage Works Outside of Development Services Schemes 4. The Developer will be required to fund works to retard flows in their own property if necessary to protect downstream development. In addition to Principle 2, works to ensure that a development does not create a flood risk for downstream properties will be funded by the developer and located on their own property. 5. Melbourne Water will fund flood mitigation works associated with existing development. Consistent with Principle 3, Melbourne Water will meet the costs associated with improved flood mitigation works or upsizing of mitigation works due to upstream-developed flows in order to provide protection to existing downstream properties. 6. Melbourne Water will fund basic works for stabilisation, revegetation and protection works to Melbourne Water waterways and creeks caused by upstream development. Costs associated with basic works such as bank stabilisation, weed eradication and revegetation to a Melbourne Water waterway or open drain due to altered flows resulting from existing upstream development will be funded by Melbourne Water. Timing of works will generally be negotiated between the Developer and Melbourne Water. 7. The Developer will fund additional enhancement of waterways and creeks above basic works. Any works undertaken by the developer to provide additional aesthetic value to the waterway or a higher level of waterway recreational value to the development will be funded by the developer. 8. Waterway Plans will be prepared by Melbourne Water. Where a Waterway Plan has been prepared, identified works may be co-funded by Melbourne Water and the developer. Restoration to degraded waterways on a developing property due to rural practices or existing land uses on the site must be funded by the developer. 9. New roads or crossing of waterways and drains will be funded by the developer or road authority. Any new road culverts or bridge crossings of existing waterways will be funded by the developer or road authority. 22

237 Table 3: Summarising the Principles Principle 1. The Developer will be required to contribute to water quality treatment works as a part of the development. 2. The Developer will be required to fund the infrastructure necessary to cater for upstream rural flows. 3. Melbourne Water will fund the upsizing of infrastructure to cater for upstream-developed flows from catchment areas larger than 60 hectares. 4. The Developer will be required to fund works to retard flows in their own property if necessary to protect downstream development. 5. Melbourne Water will fund flood mitigation works associated with existing development. 6. Melbourne Water will fund basic works for stabilisation, revegetation and protection works to Melbourne Water waterways and creeks caused by upstream development. 7. The Developer will fund additional enhancement of waterways and creeks above basic works. 8. Waterway Plans will be prepared by Melbourne Water. 9. New roads or crossing of waterways and drains will be funded by the developer or road authority. Comment Developers will be required to fund and construct on site water quality treatment to meet Best Practice Objectives for the removal of litter, total suspended solids, nitrogen and phosphorus. The developer is required to fund works to cater for existing upstream rural conditions on their property as a part of the development. Melbourne Water will fund the upsizing of infrastructure required to cater for upstream urban flows and the developer will be required to fund an amount equivalent to what would be required to construct infrastructure to cater for rural flows. Upsizing of infrastructure on the developing property to cater for the property s internal subdivisional developed flows will be funded by the developer. Works to ensure that a development does not create a flood risk for downstream properties will be funded by the developer and located on their own property. Melbourne Water will meet the costs associated with improved flood mitigation works or upsizing of mitigation works due to upstream-developed flows in order to provide protection to existing downstream properties. Costs associated with basic works such as bank stabilisation, weed eradication and revegetation to a Melbourne Water waterway or open drain due to altered flows resulting from existing upstream development will be funded by Melbourne Water. Any works undertaken by the developer to provide additional aesthetic value to the waterway or a higher level of waterway recreational value to the development will be funded by the developer. Where a Waterway Plan has been prepared, identified works may be co-funded by Melbourne Water and the developer. Restoration to degraded waterways on a developing property due to rural practices or existing land uses on the site will be funded by the developer. Any new road culverts or bridge crossings of existing waterways will be funded by the developer or road authority. 23

238 Melbourne Water Principles for Provision of Waterway and Drainage Services for Urban Growth Principles for Stormwater Quality Offsets Introduction In recent years the development industry has embraced a more sustainable approach to urban stormwater management. These efforts are being increasingly recognised for the important part they play in protecting our waterways, bays and enhancing urban amenity. Under the Water Act, Melbourne Water s drainage functions include developing and implementing plans or schemes, and taking any action necessary, to improve stormwater quality of water in drainage systems. Melbourne Water has recently introduced a Stormwater Quality Offsets Strategy to mitigate pollution impacts of urban development. The program has two major aims: (1) to uniformly apply stormwater quality standards for all development and, (2) to integrate various regional, precinct and lot scale initiatives currently underway. Current best practice for stormwater management encourages an integrated and distributed approach to stormwater quality treatment through water sensitive urban design (WSUD). WSUD treats stormwater at its source, is practical and achievable on large and small-scale developments. WSUD is about integration of water cycle management into urban planning and design. The offsets program will require developers to contribute to a combined offset fund if best practice objectives for water quality are not met within the development. Melbourne Water will use the funds generated by offsets to construct water quality treatment measures elsewhere in the Port Phillip and Western Port catchments. A developer or landowner who is required by Melbourne Water to make a contribution to the offsets program under the relevant provisions of the Water Act may object to Melbourne Water in accordance with the procedure set out in section 271 of the Water Act. Several factors have shaped the style of the offsets program. Firstly, the Government s State Environment Protection Policy (SEPP) and Environmental Management Plan (EMP) for Port Phillip Bay provide a strong basis for the use of nitrogen as a currency. Secondly, reduction in nitrogen loads has been found to be the critical factor in the sizing and costing of its treatment infrastructure and hence objectives for phosphorous and suspended sediment will also be met. In addition to government-endorsed objectives, tools for modelling loads and treatment measures are now widely accessible. Finally, Melbourne Water has been able to determine an offset price for treating nitrogen based on an assessment of past and planned regional water quality works. The Principles 1. All urban developments shall achieve best practice water quality objectives. In 1999, the Victorian Government introduced objectives for stormwater management to protect the environment from the impacts of urban development. These objectives are contained in Urban Storm Water: Best Practice Environmental Management Guidelines prepared by the Victorian Stormwater Committee (1999) and state that: 80% of the suspended solid annual load, 45% of total phosphorus and 45% of the total nitrogen annual load are to be retained to achieve stormwater management objectives. These guidelines are a referenced document in the State Planning Policy Framework and form part of the attainment program for State Environment Protection Policies including Waters of Victoria. 24

239 2. Objectives can be achieved through on-site works, a contribution to off-site works or a combination. Under the strategy, developers can achieve water quality objectives by either implementing WSUD treatment measures on-site or by paying a contribution to balance the shortfall in on-site nitrogen removal. Contributions will be spent on providing stormwater quality treatment elsewhere in the catchment. The Sustainable Neighbourhoods (Clause 56) provision requires all new residential subdivisions to meet water quality objectives within the subdivision. Offsets may be allowable for sites less than 1 hectare and where water quality is provided for in the development services scheme. 3. Nitrogen will be used as the common unit of measure for achievement of stormwater quality objectives. The contributions and effectiveness (performance) of works towards attaining best practice objectives will be assessed using nitrogen as the common unit of measurement. Nitrogen has been chosen as the unit of measurement for two principal reasons: Nitrogen was identified as the critical pollutant for Port Phillip Bay (CSIRO study, 1996) and the Government s SEPP and EMP have consequently established a nitrogen reduction target. Nitrogen provides a link (nexus) for all works within the Port Phillip catchment, where nitrogen reduction works will be benefiting the downstream receiving water body. Nitrogen has been found to be the critical factor in sizing the dimensions and capital cost of water quality treatment infrastructure. It is assumed that effective removal of nitrogen will imply an effective removal of all other typical stormwater pollutants (CRC for Catchment Hydrology 2002). 4. Outside development services schemes offsets will be based on the cost of regional water quality works designed to achieve equivalent stormwater pollutant load reductions. In 2004, all Melbourne Water constructed and planned regional wetlands were reviewed in order to establish a scientifically sound offset rate for the removal of nitrogen. The offset rate will be reviewed periodically. 5. Outside of development services schemes offsets will vary according to landuse and climatic conditions across the catchment. Pollutant loads from urban landuses across the Port Phillip and Western Port Bay catchments vary largely according to the amount of stormwater runoff. Standard residential rates ($/ha) have been developed for each of the 38 local government areas as they reflect the climatic variability across the region. 25

240 Melbourne Water Principles for Provision of Waterway and Drainage Services for Urban Growth Principles for Stormwater Quality Offsets 6. The water quality contribution in development services schemes will be based on scheme specific costs to achieve water quality objectives. Since the introduction of best practice water quality objectives for stormwater, Melbourne Water has required stormwater quality treatment measures within greenfield developments through the development services scheme development process. A scheme specific water quality offset rate is determined for each development services scheme based on the combined cost of the works and the reduction in nitrogen load that the scheme achieves. Where scheme specific water quality works do not meet best practice (in accordance with the Best Practice Environmental Management Guidelines), developers will be required to either undertake works on-site to achieve best practice, or pay an additional offset to water quality works in the broader catchment. This top up water quality rate is based on the number of kilograms the scheme is short of meeting best practice for total nitrogen. The top up rate will be reviewed in conjunction with annual scheme financial reviews. 7. Proposed development services scheme infrastructure will be reviewed in response to developers meeting objectives on-site. Where a significant proportion of the upstream developing catchment meets best practice on-site, the downstream water quality works proposed for the scheme may no longer be required to achieve environmental performance for the scheme. An analysis of the cost effectiveness of the proposed scheme works and an analysis of the resulting performance of the scheme will aid in deciding whether to construct the scheme works or not. Regardless of whether water quality works have been built within a specific scheme, rate reductions will be offered for at-source treatment, even if this results in an over performance of the scheme. In these cases, offset contributions collected from developments outside of development services schemes will be used to fund scheme works. 26

241 Table 4: Summarising the Principles Principle 1. All urban developments shall achieve best practice water quality objectives. 2. Objectives can be achieved through on-site works, a contribution to off-site works or a combination. 3. Nitrogen will be used as the common unit of measure for achievement of stormwater quality objectives. 4. Outside development services schemes offsets will be based on the cost of regional water quality works designed to achieve equivalent stormwater pollutant load reductions. 5. Outside of development services schemes offsets will vary according to landuse and climatic conditions across the catchment. 6. The water quality contribution in development services schemes will be based on scheme specific costs to achieve water quality objectives. 7. Proposed development services scheme infrastructure will be reviewed in response to developers meeting objectives on-site. Comment 80% of the suspended solid annual load, 45% of total phosphorus and 45% of the total nitrogen annual load are to be retained to achieve stormwater management objectives. Developers can achieve water quality objectives by either implementing WSUD treatment measures on-site or by paying a contribution to balance the shortfall in on-site nitrogen removal. Contributions will be spent on providing stormwater quality treatment elsewhere in the catchment. The contributions and effectiveness (performance) of works towards attaining best practice objectives will be assessed using nitrogen as the common unit of measurement. The offset rate is based on Melbourne Water constructed and planned regional wetlands. The offset rate will be reviewed periodically. Standard residential rates ($/ha) have been developed for each of the 38 local government areas as they reflect the climatic variability across the region. A scheme specific water quality offset rate is determined for each development services scheme based on the combined cost of the works and the reduction in nitrogen load that the scheme achieves. Where schemes do not meet best practice, developers will be required to either undertake works on-site, or pay an additional offset to meet best practice. The top up rate will be reviewed in conjunction with annual scheme financial reviews. Regardless of whether water quality works have been built within a specific scheme, rate reductions will be offered for at-source treatment, even if this results in an over performance of the scheme. In these cases, offset contributions collected from developments outside of development services schemes will be used to fund scheme works. 27

242 Melbourne Water 100 Wellington Parade, East Melbourne PO Box 4342 Melbourne Victoria 3001 Telephone Facsimile Copyright June 2007 Melbourne Water Corporation. All rights reserved. No part of this document may be reproduced, stored in a retrieval system, photocopied or otherwise dealt with without the prior written permission of Melbourne Water Corporation.