Could fish screens cut irrigator costs?

Every time an irrigation pump draws water from the River Murray, it can also draw in native fish, eggs, larvae, juveniles and adult fish. Fish screens are designed to prevent these losses, with research indicating they can reduce fish losses by up to 90%. But could they also deliver benefits for irrigators?

That’s the question being explored at Woolenook Fruits at Murtho, where the Murraylands and Riverland Landscape Board is partnering with a local irrigator to measure the on-farm benefits of fish screen technology.

While fish screens are already recognised for their environmental value, an investigation is underway to see whether they can also help reduce water use and deliver efficiencies in the operation of the irrigation system.

For the landholder involved in the trial, understanding the potential operational benefits is just as important as protecting native fish.

Woolenook Fruits landholder Ben Haslett said irrigation efficiency is a key consideration for the business. 

“Irrigation is the most important thing we do. So, water quality and cost are critical. We hope to see if the fish screen on the suction is an economic option in addition to the other operational benefits including decreased secondary filter flushing, post meter water savings, water depth suction flexibility and the already documented benefit to the fish population.”

Measuring the benefits on farm

A trial to compare an irrigation pump fitted with fish screens and a pump with no fish screen began on property in June 2025, to assess pump performance under similar irrigation conditions.

Filter flushing is the main area of interest as filters collect organic matter and other material drawn from the river. Over time, they become clogged and need to be flushed to maintain performance. This essential process uses water and contributes to operating and maintenance costs.

Monitoring equipment was installed at both pump sites to record water flows and track frequency of filter flushing. By comparing these results with pump operating hours, the landscape board can assess whether the fish screen influences system performance.

Early results are encouraging, with the screened pump recording fewer filter-flushing cycles per hour of irrigation than the unscreened pump. However, the two filters discharge different volumes of water per backflush cycle. This means the number of flushes alone doesn’t tell the full story, so further monitoring is needed to determine how much water is being used at each site.

The landscape board will continue collecting and validating data throughout the 2026-27 irrigation season to understand what this difference means for water use. The project will also investigate power consumption to build a clearer picture of any potential savings for irrigators.

By measuring these productivity benefits alongside the environmental benefits for native fish, the trial aims to build a stronger evidence base to support wider adoption of fish screen technology. If the results confirm on-farm efficiencies as well as environmental gains, fish screens could offer irrigators a practical way to protect native fish while improving the performance of their operations. 

This project is supported by the Murraylands and Riverland Landscape Board with funding from the landscape levies.