Australia faces many of the same water challenges seen in parts of Africa, including unreliable rainfall, water scarcity, and recurring drought. This article explores what Australia can learn from irrigation work in Ethiopia and how those lessons apply to the Murray–Darling Basin. It argues that real gains will come not from expensive infrastructure alone, but from smarter systems, steady water delivery, and better on-farm practices that reward efficiency, reduce salinity, and make water last longer during dry times.
Shared Challenges Between Australia and Ethiopia
Australia has much in common with Ethiopia when it comes to water. Both regions experience water shortages, unreliable rainfall, and periodic droughts. These conditions force difficult decisions about how limited water resources are used and managed. The Ethiopian irrigation experience raises important questions for Australia. In particular, what lessons can be applied to the rehabilitation of the Murray–Darling Basin?
One high-profile proposal in Australia has been the idea of replacing open irrigation channels with pipes. This approach, strongly promoted by Richard Pratt, highlights the water losses that occur from open channels. Piping could indeed save large volumes of water. However, the proposed cost is extremely high, with estimates of around $10 billion, or roughly $500 per person. By contrast, the Ethiopian work achieved significant gains at a cost closer to $2 per person.
Why Do Costs Differ So Dramatically?
The enormous difference in cost comes down to scale, design, and how water is moved. Large irrigation channels that flow continuously transport huge volumes of water. While there are losses, these are relatively small as a percentage of total flow. Replacing these large channels with pipes is extremely expensive, because large pipes cost a great deal to manufacture and install.
Small channels tell a very different story. These channels are often used only intermittently during irrigation and are chronically inefficient. Their losses, relative to the amount of water they move, are very high. In these cases, a small pipe costing only cents per metre can replace an inefficient channel. When combined with micro-flood irrigation and a simple tilt valve, this approach becomes a highly economic solution.
Advantages of Small Pipes and Micro-Flood Systems
Using small pipes allows precise amounts of water to be applied. This precision makes advanced scheduling techniques practical and effective. Water can be confined to the root zone, which reduces evaporation losses and prevents rising water tables that contribute to salinity. Because water is applied evenly and in controlled amounts, recycling systems become unnecessary.
These benefits show that efficiency is not just about transport losses in channels. It is equally about how water is applied in the paddock and how well irrigation matches crop needs.
Lessons for Murray–Darling Basin Rehabilitation
One of the strengths of the Ethiopian project was the ability to design the entire system from scratch. Water transport, irrigation efficiency, scheduling, and crop selection were all considered together. There was no historical, social, or political baggage. This systems approach allowed practical, low-cost solutions to emerge.
While Australia cannot start again with a clean sheet of paper, it can still apply this thinking. Ideally, the Murray–Darling Basin would be redesigned to match crops with the most suitable irrigation methods, supported by delivery systems that work in harmony with the environment.
Banrock Station as a Working Example
Banrock Station provides a strong Australian example of what is possible. It is a well-balanced and environmentally sensitive operation. The irrigators there are among the best in the country, using soil and plant monitoring and applying small amounts of water frequently.
They have successfully rehabilitated winery wetlands and integrated conservation into their operation. The land is not used solely for production. Wetlands and conservation projects improve salinity control while also enhancing tourism.
Importantly, Banrock Station does not require expensive infrastructure. Water is delivered through pipes about the size of a suburban downpipe. This simple, efficient system demonstrates that good irrigation design can reduce costs while improving environmental outcomes.
If all irrigators operated at this level of efficiency, the cost of replacing channels with pipes would be only a fraction of the proposed $10 billion.
Piping and Efficiency Go Hand in Hand
In many areas where irrigation is already efficient, piping has been adopted. The two developments reinforce each other. Efficient irrigation makes piping affordable, while piping raises the cost of water delivery, encouraging careful use.
The problem becomes clear when looking at traditional flood irrigation systems, such as dairy farms with bay lengths of 400 metres. These systems leak from start to finish. If water is applied slowly, it will not reach the end of the paddock. The only way to make the system work is to apply large volumes of water very quickly.
Losses still occur, but because they are spread across a large volume, the percentage loss appears smaller. This logic underpins much of Australia’s flood irrigation infrastructure.
Why Flood Irrigation Encourages Waste
Flood irrigation relies on delivering large, intermittent slugs of water. Channels are cheap and effective at moving these slugs, even though many channels only flow for a small fraction of the time. Pipes, however, are not a cost-effective way of delivering large, intermittent flows.
At great expense, piping solves only one problem: channel losses. It does nothing to address the far greater losses from evaporation and leakage in flood-irrigated paddocks.
Large slugs of water are also bad for crop growth. Cotton and pasture, Australia’s major flood-irrigated crops, are sensitive to saturated soils. Growth slows or stops until excess water drains or evaporates. In a dry country, it makes little sense to reduce production by over-watering.
Changing the Irrigation Paradigm
Piping water to support flood irrigation is only half a solution. It represents poor technology and poor economics. Deep-cycle scheduling, where paddocks are flooded and then allowed to dry, has become entrenched only because it is the easiest way to move water through leaky systems.
Once channels are replaced with pipes, there is no technical reason to continue using large slugs of water. Instead, irrigation can be redesigned to maintain more uniform soil moisture. This allows water to be delivered as a steady flow, which dramatically reduces the cost of piping.
Replacing channels and changing irrigation practices must happen together. The greatest benefits will come from combining local channel piping with improved on-farm flood irrigation efficiency.
Targeted Upgrades and Government Support
Upgrading irrigation systems should start with farmers willing to improve their practices. Government support, through grants and incentives, is essential. Farmers who invest in efficient systems should be rewarded, particularly during droughts.
Australia shares another challenge with Ethiopia: periodic drought. In Ethiopia, it was impossible to irrigate all cultivated land during drought. Instead, small areas were intensively irrigated using water- and nutrient-efficient crops.
The same approach applies in Australia. During drought, it is unrealistic to irrigate everything. Smaller areas under high-efficiency irrigation can help farms survive. One NSW test site, for example, irrigates 13 hectares of water-efficient lucerne using a 50 mm pipe. This is far more effective than partially flooding large areas of pasture.
Key Points for Reform
The micro-flood system, using recycled plastic piping and a simple tilt valve, is the most cost-effective way to upgrade flood irrigation. It delivers a constant flow, which sharply reduces piping costs.
Farmers need encouragement and support to adopt this technology. An integrated package is required, including grants for upgrades, priority water access during drought, and pricing structures that reward efficiency.
Improving infrastructure feeding upgraded farms by piping local feeder channels will be relatively inexpensive due to lower and more consistent flows. Losses from these small channels often exceed those from major distribution channels.
Applying the 80/20 rule shows that most water savings come from addressing losses in flood-irrigated paddocks and their local feeders. Focusing effort here offers the best chance of rehabilitating the Murray–Darling Basin.
For more information, email: colinaustin@bigpond.com
Colin Austin — © Creative Commons. Reproduction permitted for private use with source acknowledgment; commercial use requires a license.
