Purpose of the water security outlook

Transcription

1 Water Security Outlook December 2015

2 Purpose of the water security outlook The Water Security Outlook (WSO) is an annual update to Barwon Water s Water Supply Demand Strategy (WSDS), published in The WSO aims to: present updated long-term and short-term water supply and demand forecasts for Barwon Water s service region (refer to Figure 1), taking into account the climate outlook, latest inflows and any changes to demand patterns provide updates on progress in the implementation of WSDS actions revise the WSDS actions in response to a change in water security.

3 Figure 1 - Barwon Water s water supply system 2

4 How to use this document Long-term outlook The long-term forecast charts show expected water consumption levels where the level of service can no longer be met by water supply systems. An example chart is provided in Figure 2. The system yield forecast considers various climate conditions, ranging from historical climate, return to dry and CSIRO based climate change scenarios. The demand model is used to forecast water consumption, taking into account climate, population and industry growth and customer behavior, including water conservation and demand management. The combination of demand and yield forecasts on the chart provides a prediction of how long an individual water supply system is secure into the future. Both long-term and short-term outlooks are compared to the WSDS 2012 outlook. System yield (maximum annual water consumption that the existing system can support and still meet the desired level of water security) (reducing over time due to impact of climate change) Annual water consumption (demand) Water consumption forecast (typically increases over time due to regional growth) High growth Most likely growth Low growth Low climate change Median climate change High climate change Year 2016 Year 2065 Earliest timing for upgrade under worst case growth and climate scenarios Timing for upgrade under median climate change scenario and most likely water consumption growth Figure 2 - Example of a long-term chart Short-term outlook The short-term outlook presents predicted system storage levels under wet, median or dry climatic conditions over the next 12 months. Storage levels under wet climatic conditions are defined as the 95 th percentile of historic storage levels, while storage levels under dry climatic conditions are represented by the 5 th percentile. This chart provides a forecast to predict if drought response plans will need to be activated for any water supply systems over the coming year. 3

5 Climate outlook The Bureau of Meteorology forecast issued on November 19, 2015, indicates the chances of a wetter or drier summer are roughly equal across Victoria, including the Barwon region. Cooler days and nights are expected from December, 2015, to February, 2016 (Figure 3). Figure 3 - Rainfall and temperature outlook for December, 2015, to February, 2016, (source Bureau Meteorology website issued November 19, 2015). Update on action plan summary Barwon Water s region action plan summary is provided in Table 1. All systems have secure water supply status with the permanent water saving plan (PSWP) in operation, except for Colac. The PWSP is a set of common sense rules that apply every day of the year to conserve water now and for the future. As indicated in the WSDS, the Colac water supply system will need to be augmented by Planning is currently underway, please refer to the Colac forecasts for more details. Aireys Inlet will be supplied from the Geelong system when the new Anglesea pipeline is completed next year. Please refer to the Aireys Inlet forecast for more information. Table 1 Action plan summary Service region Supply status Water efficiency Supply upgrade Alternative water sources program focus Aireys Inlet Secure PWSP 2051 Connection to Geelong system ( ) Apollo Bay Secure PWSP 2064 Investigate Colac Prepare for upgrade PWSP Farms program 2019 Connection to Geelong system ( ) Geelong Secure PWSP 2051 Investigate Gellibrand Secure PWSP Lorne Secure PWSP PWSP Permanent Water Saving Plan 4

6 Greater Geelong long-term forecast Water consumption [ML/a] Earliest that upgrade may be required under worst case scenarios Likely timing of upgrade Financial year ending June System yield scenarios Water consumption scenarios Figure 4 Greater Geelong long-term forecast What was forecast in the 2012 WSDS? The long-term forecast in the WSDS indicated Greater Geelong s water supply system will remain secure well into the future with a number of new water supply sources in place. Even under extreme climatic scenarios, the system will remain secure for many years. New water sources included are Anglesea borefield, Melbourne Geelong Pipeline (MGP), Northern Water Plant and Class A recycled water schemes in Armstrong Creek and Torquay North. Has anything changed since? As a result of the bulk entitlement disaggregation, Barwon Water now has a 16 GL (2.56 per cent) share of the GL Greater Yarra/Thompson River entitlement. The new allocation provides flexibility on how Barwon Water manages its resources and maximises system yield. Further work will be undertaken to optimise the operation of water sources in The long-term graph (Figure 4) incorporates extra water available through new sources, reflecting the initiation of operation of the standby sources to maintain sufficient storage levels and required levels of service. There was a slight decrease to the demand forecast for the coming year due to revised Australian Bureau of statistics population figures and updated state government forecasts (Victoria in Future 2015). It is expected that the Geelong water supply system will be secure until

7 Greater Geelong short-term forecast Total system storage (ML) Wet Median Dry Standby water source range Start of standby water source 100% 90% 80% 70% 60% 50% 40% 30% 20% Reserve storage 10% 0 0% Sep 2015 Oct 2015 Nov 2015 Dec 2015 Jan 2016 Feb 2016 Mar 2016 Apr 2016 May 2016 Jun 2016 Jul 2016 Aug 2016 Sep 2016 Oct 2016 Nov 2016 Dec 2016 End of month Figure 5 - Greater Geelong short-term forecast What was the operational philosophy in the WSDS? The operational rule curve in the WSDS was developed to ensure that standby water sources such as Barwon Downs borefield, Anglesea borefield and the MGP are reserved for use in dry conditions and during times of water shortage. The standby water sources have enough supply capacity to withstand dry periods. Current outlook The Bureau Meteorology forecast issued on November 19, 2015, indicated a median climate was likely across Victoria, including the Barwon region, in the lead up to summer. Should conditions become very dry (5 th percentile), the storage level may hit the trigger to activate standby water sources later next year (Figure 5). 6

8 Drought response plan The Geelong water supply system has access to a diverse number of water sources. The current status of operation of each of the water sources is summarised below: Surface water (Barwon/Moorabool) Active Anglesea Borefield On standby Barwon Downs Borefield On standby Melbourne Geelong Pipeline On standby Northern Water Plant recycled water Active Black Rock class A recycled water On standby (subject to sufficient demand). Should conditions become very dry over the next twelve months, partial operation of some of the standby sources may be required in the first quarter of It is estimated that approximately 40 ML/d of additional supply would be required to stabilise water storage levels under a continued dry climate scenario. Not all standby sources are required to be operated at full capacity to deliver the additional 40 ML/d of supply. The required additional supply could be achieved by various combinations of standby sources. Over the next year, water restrictions will not be required to maintain supply under even the driest climate outlook. 7

9 Greater Geelong action plan table Table 2 Greater Geelong action plan Action Target Completion date Progress G-1 Produce annual Water Security Outlook report. Release WSO. November 30 annually Complete G-2 G-3 G-4 G-5 G-6 G-7 G-8 G-9 Complete Aquifer Storage and Recovery (ASR) research program. Engage in industry research into potential potable water reuse techniques and opportunities. Identify and deliver targeted actions to support Integrated Water Cycle Management (IWCM) Develop broad IWCM strategy for the Barwon Region Redirect water security driven water efficiency programs to Colac supply area Collect and utilise improved customer end use data Review and deliver non-revenue water reduction program Update outlook using updated growth forecasts Investigate remaining options where the timing of servicing requires action, or where efficiency gains are available. Engage and participate in industry research and trials over the next five years. a) Develop IWCM framework b) Engage where co-investment is available Finalise IWCM strategy document 2015 Redirect resourcing and budget after June 2012 Update end use accounting with new data a) Identify leakage reduction projects. b) Deliver if it proves cost effective Complete 2017 Under review a) 2012 b) 2017 a) Complete b) Under review 2012 Complete November 30 annually a) 2012 b) 2017 Complete (Fyansford and Spring Creek areas) Complete a) Complete b) Underway Complete revised forecast 2013 Complete G-10 Anglesea borefield Complete commissioning 2012 Complete G-11 G-12 Barwon Downs licence renewal Administer Permanent Water Saving Plan Complete renewal process 2019 Underway Continue current programs Ongoing Ongoing 8

10 Colac long-term forecast Water consumption [ML/a] Timing for upgrade Financial year ending June System yield scenarios Water consumption scenarios Figure 6 - Colac long-term forecast What was forecast in the 2012 WSDS? The long-term forecast in the WSDS indicated that the Colac water supply system is vulnerable to reduction in catchment yield under certain climate scenarios. This is compounded further by the heavy reliance on surface water and limited storage capacity. The WSDS forecast indicated that new water would be required by Has anything changed since? The long-term update shows that Colac water supply augmentation will be required in (Figure 6). The current timing is later than the WSDS timing due to a reduction in demand. A reduction in industrial water demand and successful implementation of agriculture demand management has resulted in lower demand over the past two years. Colac water usage consists of three major types of users: industrial, agricultural and residential. Agricultural demand has a wide margin of uncertainty due to dependence on climatic conditions and economic factors. It was also identified that Colac's industrial sector may undergo expansion in the coming years, potentially increasing its demand significantly. These factors, when considered alongside a growing population, emphasize the need to upgrade the Colac water supply. An upgrade will ensure that Barwon Water is able to cater increased demand, ensure level of service is maintained and significantly reduce the chances of supply failure. 9

11 How will Colac s water supply be upgraded? The preferred option for Colac s water supply upgrade is to source additional water from the Geelong system via the Wurdee Boluc Inlet Channel. This option provides Colac with the greatest level of supply diversity and increases the resilience of the existing water supply system and supports future growth. The Colac water supply system augmentation will be constructed in Budget has been allocated in Barwon Water s capital works investment program and planning for delivery of the upgrade is currently underway. Colac Integrated Water Cycle Management Plan This project involved investigating opportunities to integrate urban and water planning for Colac to enhance aspects of the city s water cycle system to contribute towards liveability, productivity and sustainability outcomes. The strategy has been completed and is now being used by key stakeholders as a guide for planning. Colac water efficiency program Barwon Water s Colac demand management program was initiated in The program is effective in managing short-term water security risks through a combination of water efficiency initiatives within agriculture, manufacturing, residential and commercial customer segments. Since the program was initiated, Barwon Water has facilitated the delivery of 28 water efficiency projects within the agricultural sector. It is estimated that these projects have generated water savings up to 170 megalitres per annum. There are currently a further 14 projects in various stages of planning and development for the financial year. 10

12 Colac short-term forecast 2500 Wet 100% 90% Total system storage (ML) Median Restriction range Dry 80% 70% 60% 50% 40% 30% 20% Reserve storage 10% 0 0% Sep 2015 Oct 2015 Nov 2015 Dec 2015 Jan 2016 Feb 2016 Mar 2016 Apr 2016 May 2016 End of month Jun 2016 Jul 2016 Aug 2016 Sep 2016 Oct 2016 Nov 2016 Dec 2016 Figure 7 Colac short-term forecast What was the operational philosophy in the 2012 WSDS? The Colac supply system is heavily dependent on the timing of seasonal inflows and is vulnerable to any shortening of the seasonal fill pattern. The existing storage volume is no longer sufficient to safely see Colac through periods of dry climate. Has anything changed since? Colac s historic demand has fluctuated greatly and has been difficult to predict. A new, improved short-term demand model was completed in The model is based on splitting the demand according to three key end users historic demand data. Drought response plan The Colac water supply system has small storage capacity and is dependent on the timing of seasonal inflows. Drought response for the Colac water supply system includes staged water restrictions and an education and awareness campaign. The short-term outlook (Figure 7) shows that under a continued dry climate scenario, restrictions may need to be activated over the next 12 months to maintain storages above critical levels (the reserve storage). 11

13 Colac action plan Table 2 Colac action plan C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 Action Target Completion date Progress Produce annual WSO report. Release WSO November 30 annually Complete Complete further investigations into options for Complete detailed options report 2013 Complete additional water supply in Colac. Undertake further community consultation on new Incorporate into options report 2014 Complete options for Colac. Deliver community water grants in Colac Allocate Capital Works Investment Plan (CWIP) funding for 2017 Identify new water saving initiatives for Colac Deliver non-revenue (network leakage) water reduction program. Review and update growth forecasts Administer Permanent Water Saving Plan Implement all water efficiency options in Colac Construction of Colac water supply augmentation* a) Identify opportunities and ensure initiatives installed within 12 months. b) Allocate resources to administer process June 30 (annually) up until 2016 On going complete Include in CWIP 2012 Complete a) Allocate one full time officer for five years. b) Conduct a minimum of 100 site visits. c) Identify and deliver projects or initiatives to reduce forecast demand by a minimum of 100 ML a) Identify leakage reduction projects b) Deliver if water source efficiency exists Complete revised forecasts * Action added after the WSDS had been finalised a) 2016 b) 2014 c) 2016 a) 2012 b) 2015 Ongoing a) Complete b) Complete c) Underway a) Complete b) Completed Continue current programs Ongoing Ongoing a) Develop implementation plan b) Allocate resources required c) Complete programs d) Monitor value for money against program levelised cost estimates Complete construction of new Colac pipeline a) 2013 b) 2014 c) 2018 d) Ongoing 2019 Completed each year in October a) Complete b) Complete c) Underway d) Ongoing Planning of delivery is underway 12

14 Apollo Bay and Skenes Creek long-term forecast Water consumption [ML/a] Drinking Earliest that upgrade may Water be required under worst case Demand scenarios Forecast Likely timing of upgrade Financial years ending June System yield scenarios Water consumption scenarios Figure 8 Apollo Bay and Skenes creek long-term forecast What was forecast in the 2012 WSDS? The long-term forecast in the WSDS indicated both townships would have secure water supply when the new storage and diversion point was completed in Even under the most extreme climatic scenario, this system will remain secure. Has anything changed since? The new Apollo Bay water storage basin has been completed and is now fully operational. In addition, a revised population growth rate (from Victoria In Future, 2015) has led to a decrease in the demand forecast. It is now unlikely that Apollo Bay will need a water source upgrade until 2064 (Figure 8). 13

15 Apollo Bay and Skenes Creek short-term forecast Wet 100% 90% % Total system storage (ML) Median Dry Restriction range 70% 60% 50% 40% 30% 20% Reserve storage 10% 0 0% Sep 2015 Oct 2015 Nov 2015 Dec 2015 Jan 2016 Feb 2016 Mar 2016 Apr 2016 May 2016 Jun 2016 Jul 2016 Aug 2016 Sep 2016 Oct 2016 Nov 2016 Dec 2016 End of month Figure 9 - Apollo Bay and Skenes Creek short-term forecast What was the operational philosophy in the 2012 WSDS? The operational rule curve in the WSDS illustrated the new functioning storage range of the Apollo Bay system, depicting the range of total storage used in drier years and the reserve storage. The curve also described when drought response initiatives may be needed if supply reaches critical levels. Has anything changed since? The new Apollo Bay water storage basin has been completed and is now fully operational. Barham River s flows were within median range over the past six months. While the remainder of reservoir storages have had lower volume than last year, Apollo Bay storage volume was higher than last year until September 30, Even under a very dry climate, it is unlikely that restriction will be required over the next 12 months (Figure 9). Drought response plan Drought responses for these townships would include varying stages of water restrictions, an education and awareness campaign, additional summer pumping from the Barham River to increase supply and additional water trucked in by water tankers. The short-term outlook shows that under dry climate scenarios, drought response actions will not be required in the next 12 months. 14

16 Apollo Bay and Skenes Creek action plan No further targeted actions are required for Apollo Bay and Skenes Creek (Table 3). The Permanent Water Saving Plan will continue to be applied. Table 3 Apollo Bay and Skenes Creek action plan Action Target Completion date Progress AB1 Produce annual Water November 30 Release WSO Security Outlook) report annually Complete AB2 Deliver water efficient Minimum of 30 homes or business home and business visits programs 2014 No longer required. AB3 Review growth forecasts Complete revised forecast 2013 Completed each year. AB4 Administer Permanent Water Saving Plan Continue current programs Ongoing Ongoing AB5 Secure Apollo Bay water supply for the long term a) Complete planning processes and construct additional 250 million litre storage basin. b) Upgrade the pump station on the Barham River a) 2014 b) 2014 a) Complete b) Complete 15

17 Aireys Inlet and Fairhaven long-term forecast 300 Water consumption [ML/a] Earliest that upgrade may be required Drinking under worst case scenarios Water Demand Forecast Likely timing of upgrade Financial years ending June System yield scenarios Water consumption scenarios Figure 10 Aireys Inlet and Fairhaven long-term forecast What was forecast in the 2012 WSDS? The long-term forecast in the WSDS indicated that catchment and reservoir storage would provide adequate water supply under all climatic scenarios well into the future. Even under the most extreme climatic scenario, this system will remain secure for many years. However, Aireys Inlet and Fairhaven are vulnerable to the potential impacts of bushfires in the catchment due to single source of supply. The WSDS also noted that the aging Aireys Inlet water treatment plant needed an upgrade in Has anything changed since? After considering community feedback on water treatment and supply options, Barwon Water decided to interconnect the Aireys Inlet and Fairhaven supply with the Geelong Supply System. The interconnection is less expensive than upgrading the ailing water treatment plant. The pipeline will also reduce the vulnerability to the bushfire hazard. With additional demand from Aireys Inlet and Fairhaven, the Greater Geelong system is still expected to remain secure until

18 Aireys Inlet and Fairhaven short-term forecast 500 Wet 100% 90% Total Total system system storage (ML) (ML) Median Dry Restriction range 80% 70% 60% 50% 40% 30% 20% 0 Reserve storage 10% 0% Sep 2015 Oct 2015 Nov 2015 Dec 2015 Jan 2016 Feb 2016 Mar 2016 Apr 2016 May 2016 Jun 2016 Jul 2016 Aug 2016 Sep 2016 Oct 2016 Nov 2016 Dec 2016 End of month Figure 11- Aireys Inlet and Fairhaven short-term forecast What was the operational philosophy in the 2012 WSDS? Aireys Inlet is served by a relatively large reservoir which has enough of a storage buffer that drought response initiatives are not needed under normal circumstances. A single source of supply also means that Aireys Inlet and Fairhaven are more susceptible to the potential impacts that bushfires in the catchment can cause. Has anything changed since? Storage levels behaved as expected under relatively normal climatic conditions over the past 12 months. These towns will no longer be vulnerable to the bushfire hazard when the new pipeline is commissioned in Drought response plan Drought responses for this water supply system would include varying stages of water restrictions and an education and awareness campaign. However, the short-term outlook indicates it is unlikely drought response actions, such as restrictions, will be required to maintain levels of service. 17

19 Aireys Inlet and Fairhaven action plan No further targeted actions are required for Airey s Inlet or Fairhaven (Table 4). The Permanent Water Saving Plan will continue to be applied consistent with all other service areas. With Aireys Inlet water system being connected to the Geelong water supply system in 2016, Aireys Inlet is considered secure and the water efficient home and business program is no longer required. Table 4 - Aireys Inlet and Fairhaven action plan AI-1 AI-2 Action Target Completion date Progress Produce annual Water Security Outlook report Release WSO November 30 each year Complete Deliver water efficient Minimum 30 home and business home and business visits programs - No longer required AI-3 Review growth forecasts Complete revised forecast 2013 Complete AI-4 Administer PWSP Continue current programs Ongoing Ongoing Construction of Aireys Inlet connection to Geelong water supply system* * Action added after the WSDS had been finalised Complete construction of new Aireys Inlet pipeline 2017 Construction underway 18

20 Lorne long-term forecast Water consumption [ML/a] Earliest that Drinking upgrade Water may be Demand required under Forecast worst case scenarios 100 Upgrade unlikely to be required in next 50 years Financial years ending June System yield scenarios Water consumption scenarios Figure 12 - Lorne long-term forecast What was forecast in the 2012 WSDS? The long-term forecast indicates that Lorne is susceptible to only the most extreme climatic scenario (return to dry coupled with a dry climate drinking water demand forecast). However, under the long term median scenario (most likely), the Lorne system will remain secure beyond 50 years. Water restrictions might be necessary if consumption increases significantly or if there is a return to drier conditions. Has anything changed since? Recent works on Allen Reservoir has reduced the volume of storage from 222ML to 189ML. The storage reduction is incorporated in the 2015 WSO. Even with a smaller storage, Lorne remains secure and an upgrade is unlikely to be required in the next 50 years (Figure 12). Under a very severe dry climate, the earliest upgrade would be

21 Lorne short-term forecast Total system storage (ML) Wet Median Dry Restriction range 100% 90% 80% 70% 60% 50% 40% 30% Reserve storage 20% 10% 0 0% Sep 2015 Oct 2015 Nov 2015 Dec 2015 Jan 2016 Feb 2016 Mar 2016 Apr 2016 May 2016 Jun 2016 Jul 2016 Aug 2016 Sep 2016 Oct 2016 Nov 2016 Dec 2016 End of month Figure 13 Lorne short-term forecast What was the operational philosophy in the WSDS? The operational rule curve highlights fill patterns of storages and how the storage behaves in response to an annual climate cycle. The curve also describes when drought response initiatives may be needed to extend the life of the storage if water supplies reach critical levels. Has anything changed since? Additional information has been provided to show how the storage will react under wet and dry climatic conditions. Dry conditions reduce the total runoff into catchments, placing more stress on water storages. Drought response plan Drought responses for the Lorne water supply system would include varying stages of water restrictions and an education and awareness campaign. However, even under dry climate scenarios, Lorne is unlikely to need water restrictions in the next 12 months (Figure 13). 20

22 Lorne action plan The update of the Lorne action plan is shown on Table 5. Following the review of growth and demand forecasts, the water efficiency programs are no longer required as part of the Lorne action plan. Water consumption in Lorne is relatively steady. Demand management such as the Permanent Water Saving Plan and conservation education is considered sufficient and will continue to be applied. A water supply system upgrade is unlikely to be required in the next 50 years. Table 5 Lorne action plan Action Target Completion date Progress L-1 Produce annual Water November 30 Release the WSO Security Outlook report annually Complete L-2 Deliver water efficient Minimum 30 home and/or home and business business visits programs - No longer required L-3 Review growth forecasts Complete revised forecast 2015 Complete L-4 Administer PWSP Continue current programs Ongoing Ongoing 21

23 Gellibrand River flow and demand patterns in Gellibrand show that there is no need to implement any supply or demand initiatives for the township of Gellibrand. Figure 14 shows water consumption relative to Lardner Creek flows. The average monthly flow in Lardner Creek is 2,270 megalitres, which is well above the average demand of 1.6 megalitres. During the worst year on record, Lardner Creek flows were on average 1,155 megalitres per month, which means that risk from dry climatic conditions is insignificant. For this reason, detailed supply and demand forecasts were not undertaken for this system Average river flow Average monthly flow and consumption on a logarithmic scale [ML/m] Minimum monthly river flow Maximum monthly consumption Average monthly consumption 0.1 Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep End of month Figure 14 Gellibrand water consumption relative to Lardner Creek flows Gellibrand action plan Table 6 Gellibrand action plan Ge-1 Ge-2 Action Target Completion date Progress Administer Permanent Water Saving Plan Continue current programs Ongoing Ongoing Monitor growth and Include in Water Security Outlook risks to supply process November 30 annually Ongoing 22