An environmental water release from Lake Lonsdale, which started this week, will help preserve fish and refresh water quality in Mt William Creek according to the Wimmera Catchment Management Authority.
The release is part of the Victorian Environmental Water Holder's (VEWH) Seasonal Watering Plan for the Wimmera.
The VEWH Seasonal Watering Plan takes into account the values of smaller tributary creeks that are part of the Wimmera River system, such as Mt William and Burnt Creeks. Wimmera Catchment Management Authority implements the watering plan.
The total amount of water planned for release into Mt William Creek in summer is 570 megalitres (ML), less than five per cent of the current total volume in Lake Lonsdale.
Wimmera CMA chief executive officer David Brennan said the most efficient way to deliver environmental water to the lower Mt William Creek was via Lake Lonsdale.
He said Mt William Creek was a priority waterway in the watering plan because of its healthy fish and vegetation communities.
Mt William Creek provides a refuge for several native fish species including southern pygmy perch, smelt, gudgeons and galaxia. In the past community members have reported platypus sightings in the creek.
Mr Brennan said the Mt William Creek release was separate to the environmental watering program for the Wimmera River. Environmental water from Taylors Lake is currently flowing into the Wimmera River.
"This release from Lake Lonsdale is strictly for the Mt William Creek and the small volumes reflect summer conditions," he said.
"It will involve small base flows of five megalitres per day, with occasional higher freshes of 30ML per day and periods of cease to flow over summer."
Mr Brennan said the CMA would monitor weather conditions closely during the release program.
"If we get adequate rainfall that meets the environmental requirements, we review the flows," he said.
"We will also closely monitor the upper section of the Mt William Creek to make sure it provides refuge to its many aquatic species and if needed, provide water to that section."
Mr Brennan said the CMA would also work closely with the Lake Lonsdale Action Group, Northern Grampians Shire and GWM Water to monitor water levels at Lake Lonsdale.
Wimmera CMA is also releasing environmental water into the MacKenzie River as part of its summer watering program. Releases are also planned into upper Burnt Creek in the next few weeks.
"Coming into the Wimmera summer, many sections of the Wimmera River system come under stress, so the goal of the watering plan is to strategically share environmental water resources across the Wimmera when conditions allow us to ensure we achieve a robust and healthy system," Mr Brennan said.
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