Lethbridge adopts innovative strategy to keep algae out of Henderson Lake

The City has brought in 15 aerators and 5 solar bees to help keep algae out of Henderson Lake in Lethbridge.

As the weather warms up, the City of Lethbridge is working to keep algae at bay in Henderson Lake.

“Once the ambient or air temperature rise, that warms up the water,” said City of Lethbridge’s natural research coordinator Jackie Cardinal, “and then the water won’t mix as easily so the warmer waters up top will separate from the bottom layers that are cold,” which causes algae to bloom and grow.

Some types of algae -- including blue-green -- can be toxic to both people and pets.

To deal with the algae, the city has installed 15 Aerators to keep oxygen moving in the lake, along with five solar bees to help move the water.

The city is also working with Lethbridge Polytechnic to monitor and sample the lake every two weeks.

The city has begun the process to import a product to treat algae, however it has not yet been approved by the federal government and won’t be here until next spring.

The city says Henderson is the only lake in the city that has algae.

“It has a very healthy waterfowl population, which through our research process, we found out contributes about 33 per cent of the phosphorus load to the lake all by themselves,“ said Cardinal.

“Another 30 per cent is from fertilizer use, both from the park and golf course and then the rest of it comes from stored in the sediments.”

While algae is not present now, the city is asking residents to not drink the water and keep pets out of the lake.