Cooby Dam faces potential blackwater as it prepares to re-open this week

A dam near Toowoomba has seen a large number of fish wash up dead, with potential blackwater as a result of horror floods this week. Details here.

A POSSIBLE “blackwater” event has resulted in a large fish die-off at a dam north of Toowoomba, ahead of its reopening this week.

Cooby Dam’s Loveday Cove is expected to open for recreational use this week, however late last week, fish were found floating on the shore lines.

“On Friday morning I received reports of dead fish floating in Cooby,” Cr Tim McMahon said.

“By Friday night it had turned into a large, significant fish die-off.

“Further testing is being undertaken to determine the exact cause of the fish deaths, as we are not attributing it to the bacterial or algal levels at this stage.

“We also do not suspect there is any chemical involved.

“Species involved include eel-tailed Catfish, Yellowbelly, shrimp and some Murray cod.”

Mr McMahon said flooding across the region was the cause of a possible “blackwater” event.

A blackwater event is where organic materials are washed into the system and are consumed by bacteria, leading to a lose of oxygen and rise in dissolved carbon in the water.

“This grieves me deeply, and we will need to work on restocking of native species once we know the cause,” he said.

“Waterways health is everybody’s business, and we need to protect our native species and delicate ecosystems.

“Council officers have reported the event to the Department of Environment and Science and are continuing to investigate the cause of the incident, while cleaning up the dead fish in anticipation of reopening the dam to the public.”

Footage of Cooby Dam at full capacity.

Meanwhile, the council has adopted new dam recreation use guidelines in a bid to reduce the frequency of closures.

While Loveday Cove will open at an unknown date this week, the dam wall will remain closed.

The council has confirmed there are no water quality issues with Lake Cressbrook or Lake Perseverance.

There are also reports of the invasive Tilapia fish being found in Cooby Dam.

Mr McMahon said it was yet to be confirmed, however the fish caused massive damage to waterways and native numbers.

“If we find them in Cooby it will be the first time they are identified in the Murray-Darling catchment, and it will be a high alert,” he said.