The Wimmera Catchment Management Authority (CMA) is releasing water for the environment from Taylors Lake into the Wimmera River to freshen it up with support from the Victorian Environmental Water Holder and GWMWater. Pumps are also being used in a trial to keep the water aerated to minimise the effect of organic material decomposition on fish and other aquatic life in the river.
In late-January 2021, natural flows in the Wimmera River and its tributaries caused poor water quality in some parts of the river.
Wimmera CMA CEO, David Brennan, said the intensity of late January rainfall caused a sharp and short peak which picked up large volumes of silt, leaves and other organic material. This was left behind as the peak dropped.
“This is an issue particularly in weir pools and back waters where vegetation debris has fallen out,” Mr Brennan said.
“At the moment the colour of the water is dark.
“Native fish can tolerate some harsh conditions, but our concern is around the accumulated organic material decomposition process which sucks oxygen from the water, leaving little for fish and other aquatic life.
“It is worth keeping in mind the environmental flows are small compared to the natural flow which went through Horsham last week and arrived in Jeparit on Wednesday, but every bit helps.”
Wimmera CMA is closely monitoring water quality and working with GWMWater, Horsham Rural City Council, Horsham Fishing Competition Committee, Victorian Fisheries Authority, Department of Land Water Planning and specialists from the Environment Protection Authority and Arthur Rylah Institute.
Mr Brennan said water quality events like this were a natural process of the Australian ecosystem but they were keen to pursue options that could minimise the impacts.
“Currently, we are trialling pumps to aerate the water in some locations,” Mr Brennan said.
“Also, our staff are continually monitoring water quality from Jeparit to Campbells Bridge to understand where the issues are.”
Mr Brennan asked the community to keep an eye on the river and let the CMA know if they noticed anything of concern.
“We encourage the community to keep an eye out for anything unusual and if they have any information or queries to please contact our office by phoning 5382 1544,” Mr Brennan said.
“This is a challenging situation, and we are doing everything we can.
“But we are going to have these water quality issues for a number of weeks, unless we get more rain and cooler temperatures.”