Irrigation renewal means rationalising and improving the efficiency of our outdated irrigation system while upgrading and investing in its future.

It involves the automation and upgrading of channels, construction of pipelines, upgrading the accuracy of metered outlets to farms and lining and remodelling of channels. These works, in combination with system operational changes, will improve service levels to irrigators and save billions of litres of water. Significant system efficiency improvements will be made possible by transforming a ‘manually’ operated system to a fully automated delivery system measuring water flows quickly and accurately.

Channel automation 

Channel automation is a way of improving the efficiency of irrigation networks by using new technology to control the flow of water from the storage (usually a dam) through the distribution system to the irrigator. It involves replacing manual flow control structures in channels with updated gates that accurately measure flows, provide real time measurement data and, in most cases, are automated. This, in turn, allows more accurate location of the worst seepage and leakage losses and more effective targeting of channel remediation works.

Automation of the gates also provides the ability to interact with meters and on-farm automation equipment, so best practice irrigation methods can be employed on farms. Other benefits include constant flows and water on demand.

Pipes and channels

Much of our irrigation system relies on open channels to transport water. Leaky sections and inefficient operation result in up to 30 per cent of the total volume being lost. Water losses can be minimised by lining, remodelling or pipelining parts of the channel system.

Improved meter accuracy 

Victoria’s northern irrigation systems contain about 18,000 Dethridge wheels to measure diversions onto irrigation property.

Dethridge wheels become inaccurate through general wear and tear and on average, under-measure water delivery by 10 per cent. As such, they will not be able to meet the new metering standards being introduced by the Australian Government. The new national metering standards will require a maximum of plus or minus 5 per cent measurement accuracy. There are also occupational health and safety risks associated with using Dethridge wheels.

Around 15,000 of these Dethridge wheels will need to be replaced with more accurate devices such as electromagnetic flow meters and flume gates, depending on the needs of the site. Many of these meters will be automated, enabling water to be delivered on-farm without the need for manual operation by irrigators.  Based on these new standards, without the irrigation renewal project, these replacement costs would have had to be met by irrigators.

Future water costs

Future water charges for the new system will be determined as part of the regulated pricing process run by the Essential Services Commission. It is expected that the upgrades will achieve operational and maintenance cost savings. However, there will be new costs associated with running a modern system.

Farm systems

Rationalisation and renewal of the delivery system cannot be undertaken without simultaneously adjusting farm systems to allow optimum connection to the new system. For example, a farm with six outlets may choose to move to one or two outlets under a modern system, requiring adjustment of farm layout. 

Planning, consultation and decision making

Work to upgrade regulators and other infrastructure on the major channels in northern Victoria’s irrigation delivery system has begun. However, some areas currently serviced have traded water out or changed enterprise type and will require a different service in the future. Communication, consultation and works programs will:

• Provide irrigators with up-to-date information on when, where and what is happening.
• Inform irrigators of the opportunities for improved farm operations from better delivery services.
• Request information from irrigators on the levels of service required by their different farm enterprises and operations.
• Help identify where different types of delivery services are required.
• Provide advice and planning services to those farmers wanting to upgrade their operations.