TWO water circulators will be installed tomorrow as part of a three-year trial to improve the water quality of Lake Burley Griffin.

The solar-powered water circulators, to be installed on the river and the lake basin, will be paired with other untreated sites with similar characteristics, for comparison. The first year of the trial, including the purchase of the units and the testing will cost $350,000.

“There’s strong scientific evidence that water circulators can help reduce the intensity of blue-green algae blooms,” National Capital Authority chief executive Gary Rake said.

“The nutrient that comes down the river is in a bound form, which blue-green algae cannot readily access.

“When it hits stratified water it becomes unbound.  The water circulators will interrupt the stratification of the water in the lake, so the nutrient can stay bound.

“The first water circulator will be installed in Molonglo Reach, with a control site upstream on the Molonglo River.

“The second will be installed near the swimming beach at Yarralumla Bay, and it will be paired with a site in Orana Bay for testing.”

The units will float on the water and at five metres in diameter, are the same size as the water pontoons already in the lake. If the trial is successful, the NCA will consider the installation of more units throughout the lake.