A LARGE section of the Gunbower Creek will be lowered during the irrigation off-season to allow for the construction of fishways at the Cohuna and Koondrook weirs.
Water for the environment and irrigation water won’t flow down the creek until the start of the new irrigation season on August 15.
As a result, the water level has already started to drop. The lowering will be more noticeable in some sections of the creek than others, with only deep pools remaining in stretches.
At the Cohuna weir pool, the water level will be lowered about one metre below the full supply level.
The town supply will not be impacted by the lowering, and Goulburn-Murray Water (GMW) has communicated with relevant stock and domestic customers.
“Up until 2013-14, Gunbower Creek dropped from May to August as part of the annual irrigation shutdown period,” GMW general manager infrastructure delivery services Warren Jose said.
“Since then, water for the environment has kept the creek flowing to help native fish such as the Murray cod survive and thrive.
“This is a one-off lowering to allow us to complete a key section of the Cohuna and Koondrook fishway works.
“We are lowering the creek now to ensure we don’t impact irrigation delivery. Once irrigation season begins, the flows will recommence.”
North Central Catchment Management Authority (CMA) major projects executive manager Tim Shanahan said the fishways would be a boon for the creek.
“Both weirs are the last barriers to fish passage along Gunbower Creek,” he said.
“The fishways will allow fish, including the vulnerable Murray cod which are breeding in Gunbower Creek, to safely move downstream into the Murray River, and to move upstream and recolonise sections the upper reaches of the creek.
“The Koondrook fishway will provide year-round passage to native fish such as golden perch, Murray cod and Threatened silver perch from the river into the creek for the first time in more than a century.”
Conditions in the creek will be monitored during the drawdown.
The Cohuna fishway is fully funded by GMW and will comprise of a 23-slot vertical slot fishway attached to the existing Cohuna weir.
