Waimakariri District Council is trialling a new approach to increase aeration of Lake Pegasus in an attempt to rid the waterway of seasonal algal bloom.
While monitoring buoys are already in place, Pegasus residents will see some activity around the lake as the equipment is being installed this week, the Council said in a statement.
“The trial will focus on a specific section of the lake that will be separated from the rest of the lake. There will be an air compressor installed under the small footbridge and curtains underwater to form the trial area,” Council said.
“The airline and aeration equipment will be put into the trial area near to the yellow buoy in the southern part of the lake. They will be on the bottom of the lake so not visible from the surface.”
Council said there will be some testing of the equipment to ensure it’s running correctly before it is deployed continuously.
“The monitoring buoys in the lake support the aeration trial. They will regularly measure oxygen and temperature in the water and this data will be used to determine the effectiveness of the aeration trial,” it said.
“Increasing oxygen levels in deeper parts of the lake should help with water quality. In addition the aeration in the water will help develop currents, disrupt the algae, create more movement and make the lake less stagnant.”
While the mitigation option shows promise, it’s not guaranteed to prevent of algal blooms in the lake, Council warned.