Integrated water resource assessment for the Adelaide region, South Australia

Transcription

1 Integrated water resource assessment for the Adelaide region, South Australia J. Cox 1,2, M. Akeroyd 1 and D. Oliver 1,3 1 Goyder Institute for Water 2 SARDI 3 CSIRO

2 This presentation Focus on the integrated water resource assessment of the northern Adelaide region of South Australia by the Goyder Institute for Water Including the key research investments in water and climate, and how this information is being utilised by decision makers in the region

3 Background South Australia (SA) is the driest state in the driest inhabited country in the world, Australia. Consequently, water is one of SA s highest priorities Water resources the River Murray (Murray Darling Basin, MDB), reservoirs in the Mt Lofty Ranges and groundwater (also desalination plant) Pressure on these sources of water is expected to increase with a decrease in average annual rainfall in the northern Adelaide region of approximately 8 17% SA s population is expected to grow from 1.67 million people to reach 1.79 million by end 2016 and 2.28 million by 2036, increasing the demand on water supplies

4 Background (cont.) Focus on water research and sources of water in the state became more critical during the Millenium drought that occurred between 1997 and 2011 in the MDB

5 Murray Darling Basin Area of MDB 1.06 million km 2

6 Establishment of the Goyder Institute for Water Research in South Australia South Australian government established The Goyder Institute for Water Research in 2010 a partnership between the South Australian State Government, the Commonwealth Scientific and Industrial Research Organisation (CSIRO), Flinders University, University of Adelaide and University of South Australia The Goyder Institute undertakes cutting edge science to inform the development of innovative integrated water management strategies to ensure South Australia s ongoing water security and enhance the South Australian Government s capacity to develop and deliver sciencebased policy solutions in water management

7 Adelaide Location of the Goyder Institute for Water Research

8 1. Adelaide Plains Groundwater This project has built upon existing knowledge to provide a thorough assessment of the groundwater resources beneath Adelaide, and the impacts of current and future extraction and climate change Modflow model and water balance (airborne geophysics for remote areas of SA) It is the first study to provide an integrated assessment of the groundwater resources of the entire Adelaide metropolitan region

9 2. Managed Aquifer Recharge and Stormwater Use Options Assessed a range of potential uses of stormwater including via managed aquifer recharge Addressed the health risk assessment of uses for public open space irrigation, third pipe non potable supplies to households and industry and for drinking water supplies For several of those uses prototype risk management plans were developed. The economics of some specific options were also considered taking account of environmental impacts, and surveys of public acceptance of the more novel options that were considered

10 3. Mt Lofty Ranges Catchment Source of surface water for Adelaide reservoirs Understand environmental water needs, patterns of flow and water quality within the catchment Collecting hydro ecological data and water quality assessments that support development of water allocation plans for the region, including installing monitoring equipment in high priority regions to measure water flow and quality and the subsequent ecological response from fish, vegetation and macroinvertebrates To support decision making, a tool (DSS) has been developed that brings together all the information needed to make robust decisions on water allocations and assess the potential outcomes of alternative management options Source model platform developed

11 Mt Lofty Ranges

12 4. SA Climate Ready SA Climate Ready is the most comprehensive set of downscaled climate projections data ever available in South Australia. Data is available for six climate variables (rainfall, maximum and minimum temperature, areal potential evapotranspiration, solar radiation, and vapour pressure deficit), using two emission scenarios (intermediate and high representative concentration pathways ) through to 2100 The data can be used in future planning decisions. For example, the impacts of climate change enable water resource and catchment managers to assess the security of future water supplies and protect water supplies for all water users

13 5. Stormwater Interventions linking catchment actions to coastal water quality The government of SA is developing an Integrated Urban Water Management Plan (IUWMP) for Greater Adelaide that will embrace all available water sources including stormwater and wastewater Currently, investment in stormwater and wastewater infrastructure is made or guided by state and local government agencies of South Australia. This does not currently include an evaluation of the relative effectiveness and efficiency of the investment (separately or in combination) in achieving goals such as water supply security, flood management and improved receiving water quality Information is required to address the most efficient and cost effective way to manage stormwater and wastewater discharges to improve coastal water quality

14 Northern Adelaide Plains

15 Background to the Northern Adelaide Plains Main land uses: urban development (particularly in the south); horticulture, viticulture and annual crops; light industry; and cereal grain cropping and sheep grazing toward the north Reliable rainfall (from around 400 mm/y near the coast to around 650 mm/y at the foot of the ranges) Access to reliable water sources for irrigation. High quality underground water from confined sand and limestone aquifers beneath the plains has supplied NAP irrigators for many years and since 1999 this has been supplemented by tertiarytreated wastewater delivered via a pipeline network from the Bolivar wastewater treatment plant Producer of high value horticultural crops since the late 1950 s. Conducive to the production, and efficient distribution, of a wide range of annual market garden crops and perennial tree and vine fruit Potential to expand?

16 Application of findings to Northern Adelaide Plains Adelaide Plains Groundwater We now have a full water budget and model for the NAP Groundwater extractions occur from Tertiary limestone aquifers. Metered extractions total 14,713 ML, well below the current allocation of 26,500 ML Salinity levels have been stable over the past 10 years. However, there is lateral inflow of more saline groundwater toward cones of depression in irrigation areas Opportunities to use re use water

17 Application of findings to Northern Adelaide Plains Climate Ready Downscaled climate change projections future climates generated at a local scale There are over 40 global climate models (GCMs) for generating climate projections. The Goyder Institute identified a subset of these GCMs based on their ability to reproduce the State s climate drivers such as the Indian Ocean Dipole and the El Niño Southern Oscillation (ENSO). This sub set of GCMs were then used to generate climate projections at a local scale Climate modelling suggests that average annual rainfall in the NAP could decline by up to 7.8 to 17.4% by the end of the 21st century. In addition, average annual maximum temperatures have been modelled to increase by 1.8 O C to 3.4 O C The type of crops grown may have to be re assessed.

18 Conclusions The findings from projects from the Goyder Institute for Water Research are providing valuable data and models for planning future development in the NAP region. The research will allow better integration of current available water sources and projections of the effect of increasing demands on these sources.

19 Thank you Beecham, S (2015) Development of an agreed set of climate projections for South Australia: Final Report. Goyder Institute for Water Research Technical Report Series No. 15/3, Adelaide, South Australia. ISSN: (PDF 1.88 MB) Vanderzalm, J, Page, D, Gonzalez, D, Barry, K, Toze, S, Bartak, R, Shisong, Q, Weiping, W, Dillon, P and Lim, MH (2014) Managed Aquifer Recharge and Stormwater Use Options: Satellite Sites Stormwater Quality Monitoring and Treatment Requirements for Potable Supplies. Goyder Institute for Water Research Technical Report Series No. 14/10, Adelaide, South Australia. ISSN: (PDF 1.60 MB)