Algal blooms and lake closures

Our lakes have a dual purpose. Designed not only for recreation and to provide a beautiful focal point, they also play an important role in cleaning stormwater.

Big concrete stormwater drains built in the 1960s and 1970s were designed to rapidly move rainwater away from our homes and streets and into our lakes. The lakes then trap the pollutants carried by the stormwater and run-off and prevent them travelling downstream into the Murrumbidgee River and the wider Murray-Darling Basin.

Our lakes do a good job of protecting the river, particularly during major rain events when large amounts of pollutants, nutrients and sediment are washed into the stormwater system.  However, over time and particularly after heavy rain, the build-up affects water quality and lakes may be closed.

The most common reason for lake closures in the ACT is blue-green algal blooms. There are actually three types of blue-green algae, generally occurring at different times of the year. They are all toxic to dogs when ingested and potentially hazardous to humans, causing symptoms such as eye or skin irritation, sore throat or gastro-enteritis. Lakes are closed when algal levels are high enough to be considered a risk. Read more about algal blooms and what causes them.

ACT Healthy Waterways funded independent research to better understand how the pollutants that blue green algae feed on get into our waterways.

Get more information about blue-green algae, monitoring, lake closures and alerts on the TCCS website.

Find out what you can do to help keep stormwater clean.