Blue-green algae advisory remains in place for Henderson Lake Park as Lethbridge temperatures heat up ahead of long weekend

An advisory remains in place for Henderson Park Lake in Lethbridge over concerns that the lake has Cyanobacteria (blue-green algae). (Photo: X@CityofLethbridge)

With mid-summer temperatures in the forecast for the long weekend, the City of Lethbridge issued a reminder Thursday that a Cyanobacteria (blue-green algae) advisory remains in effect for Henderson Lake Park.

Cyanobacteria can appear on the surface of the water like scum, grass clippings, fuzz or globs in the water and can be green, blue, brown or pinkish red.

It often smells musty or grassy.

This week’s rain helped improve conditions but hot weekend temperatures might make things worse.

Contact or ingestion of water containing Cyanobacteria can result in skin irritation, rash, sore throat, eyes and swollen lips.

Those ingesting the water may experience fever, nausea, vomiting and diarrhea.

Symptoms usually appear within one to three hours and can be resolved within a day or two. For children, the symptoms might be more pronounced. For pets, consuming Cyanobacteria may be fatal.

Visitors to Henderson Lake Park this weekend are advised to avoid any contact with water exhibiting signs of Cyanobacteria. If contact does occur, wash with tap water as soon as possible.

Officials also offer the following advice:

Don’t let pets or kids swim in the lake;

Don’t feed whole fish or fish trimmings from the lake to your pets; and

Consider limiting human consumption of whole fish and fish trimmings from this lake.

Lethbridge treats the lake monthly with a beneficial bacteria designed to limit the growth of nutrients that encourage blooms. However, there are no treatments available to stop or control Cyanobacteria blooms.

The advisory will remain in place until further notice.