TOOLEYBUC residents are hoping the opening of Lake Coomaroop will help reduce flooding in the area.

The shallow ephemeral lake, which is privately managed by the Minnie Bend Flood Prevention Trust, is capable of holding about 3200 megalitres of water.

Secretary Tracey Domaille said the regulator to the lake was opened on Monday and it would probably take a couple of weeks to fill from the Murray River.

Ms Domaille said the trust had resisted calls to open the lake sooner, waiting for the time when it would have the greatest impact.

“Six to eight weeks ago, when things started happening upstream, people started saying, ‘You should be opening the lake’,” she said.

“If we’d opened it that long ago, it would be full now. And there would be no opportunity to get rid of any water out of the river. So that’s why the decision was made now to get rid of the water because now is when we need to get rid of the water.”

The trust’s 5km levee bank protects 14 properties and a handful of houses, including Ms Domaille’s, between the lake and the Murray River. It also stops water from cutting the roads to Koraleigh and Balranald.

In the early days, farmers were allowed to crop or graze Lake Coomaroop when conditions were suitable, but Ms Domaille said it had since been rezoned to be used solely for flood mitigation.

“The people in Tooleybuc think, ‘Oh, we’re going to have this great lake’,” she said.

“We’re not. It’s full of cracks and a heap of grass, so it’s going to be like the river, but still.

“Last time it had water in it, me and my husband went down to have a look. And we hopped out of the ute to open the gate and just hopped back in the ute. There were way too many mozzies.”

The last time the lake filled was when “some rogue” cut the lock and opened the regulator, she said.