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

The Goulburn Murray Irrigation District

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 performance pre- Modernisation Water Within the District Goulburn component of GMID Murray component of GMID Total Goulburn-Murray Irrigation District Average Inflows Reduced Inflows Average Inflows Reduced Inflows Average Inflows Reduced Inflows GL Actual Diversions at river offtakes On-Farm Metered Allocations to Irrigators Losses due to System Inefficiency Total System Efficiency 69% 63% 67%

Ref: DSE, 2008 System losses

Key recommendations 1.Improve metering accuracy 2.Consistent framework for calculating efficiency 3.Confirm findings with further detailed studies 4.Resolve policy issues eg. savings from better measurement 5.Develop water conservation plans across the GMID 6.Address issues created by reduced outfalls 7.Adopt a strategic approach to modernisation investment

What happened next? >“Millenium” drought >Foodbowl modernisation 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 o Long notice required for water orders o Variable flow rates and channel height o Low flow rates o Manually operated Dethridge wheel outlets o High water losses o Risks of high costs to maintain into the future o Difficult to achieve the size of property required to generate economies of scale

Foodbowl modernisation initiative

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 o Water available close to on-demand o Higher and more consistent flow rates o Modern, customer operated and controlled automated outlets that can be integrated with on-farm systems o Improved 24/7 monitoring and response o Best practice water delivery efficiency

Ref: DSE, 2008 Modernisation framework

Channel automation

Metering upgrades

Channel lining

NVIRP progress

Targeted investment approach

Lessons Learned 1.Clear vision and objectives – what are we trying to achieve? 2.Early stakeholders involvement and engagement 3.Good quality data is essential 4.Holistic approach that includes the supply system and on-farm system 5.A sustainability based, strategic approach to investment decisions 6.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