SA Water has launched a comprehensive fish population study for the first time in Warren Reservoir to support a planned upgrade of the dam’s intake and scour valves next year.
According to SA Water’s General Manager of Sustainable Infrastructure, Amanda Lewry, data from the study will be used to inform how the native fish can be safely relocated to the nearby South Para Reservoir while Warren’s water level is lowered temporarily for its valves to be upgraded.
Ms Lewry said the fish study was an important part of planning for the project, which has been underway since 2016.
“Warren Reservoir Reserve in the Barossa Valley is one of several reservoir reserves that have been transformed into thriving recreational destinations supporting community wellbeing, with the reservoir particularly popular among anglers,” Ms Lewry said.
“To balance preserving the reservoir’s recreational role with our emphasis on dam safety, we’re partnering with RecFish SA and its members, the South Australian Research and Development Institute, and commercial fishers to monitor and then relocate, as much as possible, the valuable native fish including Murray cod, Silver Perch and Golden Perch, before we lower the reservoir to near zero capacity” she said.
“As part of the monitoring stage of the study, we’re catching native fish … to record their size and species, tag and then return them to the reservoir.”
She said the analysis would help build a picture of the fish population to understand how the changes in oxygen levels would be likely to impact on lowering the water level and affect the fish.
“Lowering the reservoir will enable the valve upgrade to be completed safely and efficiently, which ensures we can return it to full capacity as quickly as possible.”
Ms Lewry said that for the safety of crews and the community during the valve upgrade, Warren Reservoir is to be temporarily closed to visitors for on-water access from February 2023, with a partial closure of the reserve’s western section from April 2023.
She said the valve upgrade was part of a long-term initiative to elevate dam safety at Warren, in line with refreshed national guidelines.
“While the reservoir’s water level is temporarily lowered, we’ll also be performing a detailed investigation of the structures that are normally underwater, to help inform our understanding of the dam as part of our long-term dam safety upgrade program,” Ms Lewry said.
She said Warren Reservoir provides a direct supply of water for irrigation for around 85,000 customers in Adelaide’s northern suburbs and nearby townships.
