Water savings in the Goulburn Murray Irrigation District

The journey from 2000 to 2012

Stephen Harding and Ian MoorhouseIrrigation 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 GL GL GL GL GL

Actual Diversions at river offtakes 1780 1350 1110 985 2890 2335

On-Farm Metered Allocations to Irrigators 1305 932 715 623 2020 1555

Losses due to System Inefficiency 475 418 395 362 870 780

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