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1 STATE WATER STRATEGY Office of Water Strategy Jos Mensink Director Office of Water Strategy August 2005 www.ourwaterfuture.com.au

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2 Runoff to Hills dams in 2001 only 30% of 25 year average - about 40 GL compared to average of 180 GL. Inflow in 2002 only slightly better with about 90 GL. Combined inflow for those two years is the worst on record. Water becomes one of top three community issues and Government established the Water Taskforce. 19 Water forums held in 2002 (9 metro area, 10 regional) and Parliament House Symposium in October 2002 to build framework for the State Water Strategy. State Water Strategy released February 2003. 2003 runoff was about 150 GL. S hort History of State Water Supplies

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3 Rainfall 14% less 21% less 2001, 36% less Streamflow Percentage changes are relative to 1911-1974 period 52% less 64% less 2001, 88% less

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4 Informed adaptation to climate change Decrease Last quarter century winter rain as % of previous 75 years A drier and warmer climate for the SW

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5 Water Resources Portfolio Water Resources Cabinet Sub Committee Chair: Premier State Water Council Chair: D Hatt - Office of Water Strategy - Senior representatives from Government Agencies - Water Service Providers - Ministerial Advisors New Water Resources Entity by 1/9/2005 Water Utilities - Water Corporation - Busselton Water - AQWEST Bunbury Minister for Water Resources Premier (Option) Minister Assisting in Water Resources Hon J Kobelke Department of the Premier and Cabinet Policy Division Office of Water Strategy Strategic Policy and Planning J Mensink (Director) Senior Steering Group (DPC, WC, DoE, DTF)

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6 The Office of Water Strategy provides high level advice to the Government in relation to water strategy and facilitation and coordinates Government activity including new water source developoment, demand management and water reuse. It also provides support to the Premiers Water Foundation and other Committees involved in the implementation of the State Water Strategy. The Governments preferred option for longer-term administrative support for the Water Resources Portfolio should be substantially progressed by September 2005. The State Water Council consists of nominated senior representatives from government agencies, ministerial advisers and water utilities. The Council acts as a forum on water related matters and provides advice to the Water Resources Cabinet Sub-Committee. Roles

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7 Gnangara Mound

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8 Identified potential GDEs not previously considered based on depth to groundwater mapping of Gnangara Mound. Gnangara >400 wetlands 33 Bush Forever Sites supporting areas of phreatophytic terrestrial vegetation 6 mound springs 4 caves near shore marine systems. Identified ecological values of new GDEs Outlined changes in ecological condition (where assessed)

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9 Gnangara Mound

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10 Climate 2 Decline predictions @ 2015 28 year Monthly Median 8 year Monthly Median

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12 Future abstraction for public water supply Demand: assume the 155 KL/person demand target is met by 2012 New sources: 45 GL/yr Perth Seawater Desalination Plant by late 2006 17 GL/yr water trade by 2008/09 45 GL/yr South West Yarragadee by late 2009 Drought security: ~0.5% chance of a total ban on sprinklers Groundwater abstraction: Gnangara groundwater is critical a variable allocation between 105 and 165 GL/yr depending upon storage in dams will secure the IWSS

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13 Gnangara Mound Aquifers AquiferThickness (m) Storage (GL) Salinity (mg/L) Water Corp Abstractio n (GL/yr) Superficial20 to 70>20,000