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Water savings in the Goulburn Murray Irrigation District T he journey from 2000 to 2012. Stephen Harding and Ian Moorhouse Irrigation Australia Conference, Adelaide June 2012. Overview. The water savings study in 2000 What happened next? Where are we now? Lessons learned.
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Water savings in the Goulburn Murray Irrigation DistrictThe journey from 2000 to 2012 Stephen Harding and Ian Moorhouse Irrigation Australia Conference, Adelaide June 2012
Overview • The water savings study in 2000 • What happened next? • Where are we now? • Lessons learned
Study objectives • Reduce water losses by at least 50 GL • Determine the volume of savings • Quantify the initial and continuing costs • Identify priorities for water saving measures • Identify processes for verifying and quantifying water savings
System losses Ref: DSE, 2008
Key recommendations • Improve metering accuracy • Consistent framework for calculating efficiency • Confirm findings with further detailed studies • Resolve policy issues eg. savings from better measurement • Develop water conservation plans across the GMID • Address issues created by reduced outfalls • Adopt a strategic approach to modernisation investment
What happened next? • “Millenium” drought • Foodbowlmodernisation initiative • NVIRP project
10 Years of Drought • Driest 10 yrs on record • Involves adjusting climate model results to a local scale • Usually involves use of local-scale historical data to ‘calibrate’ and ‘validate’ the model 10 Year Rainfall Deficiencies 1 Jan 1997 – 31 Dec 2006
Challenges with existing distribution network • Extensive spur channel supply system • Long notice required for water orders • Variable flow rates and channel height • Low flow rates • Manually operated Dethridge wheel outlets • High water losses • Risks of high costs to maintain into the future • Difficult to achieve the size of property required to generate economies of scale
Benefits of modernisation • Remove most of the small local channels allowing properties to be amalgamated and supply systems rationalised, with improved paddock access when G-MW channels are removed • Provide a far higher level of service at the farm gate with • Water available close to on-demand • Higher and more consistent flow rates • Modern, customer operated and controlled automated outlets that can be integrated with on-farm systems • Improved 24/7 monitoring and response • Best practice water delivery efficiency
Modernisation framework Ref: DSE, 2008
Lessons Learned Clear vision and objectives – what are we trying to achieve? Early stakeholders involvement and engagement Good quality data is essential Holistic approach that includes the supply system and on-farm system A sustainability based, strategic approach to investment decisions Real gains are possible both off- and on-farm
Summary • Biggest modernisation program in the world • Fundamental change in thinking • Far reaching consequences for irrigators, communities and the environment • Significant benefits still to be realised on-farm