Project

Oxygenation to support Native Fish in the Darling-Baaka River.

Location

Lower Darling River at Menindee.

Requirement

Fish deaths in stretches of the Darling occurred in 2019 due to hypoxia (loss of dissolved oxygen which is required by fish), linked sudden weather driven mixing of stratified waterbodies.

Millewa Pumping were approached by NSW DPI Fisheries to design and trial a custom-made pump and venturi system to oxygenate poor quality water in the Darling-Baaka River during drought to support native fish (including Murray Cod). These systems draw hypoxic water from the river and return oxygenated water.

After proving successful in preventing localised fish deaths, the process was expanded to incorporate larger aeration outcomes in the river adjacent to Menindee Town, as well as in isolate refuge pools in the Lower Darling-Baaka region during record drought. These included:

·         Four 10” multiport aerator units

·         One 12-inch pump-driven venturi aerator

·         Two 26-inch pump-driven venturi aerator

The fish these aerators helped to survive were able to contribute to the recovery of native fish populations in the Darling-Baaka when flows subsequently returned in 2020.