The Oregon Health Authority collects and tests water from Hagg Lake for harmful algae, which can make you, your children, and your pets ill. Swallowing the water can be even more hazardous.
There are currently no algae warnings at Hagg Lake.
However, the OHA advises you to rinse off afterwards if you go into the lake. And know what to look for:
Don't go into water that looks foamy, scummy, thick like paint, pea-green, blue-green or brownish red. A good rule of thumb for you and your pet is: When in Doubt, Stay Out!
Here’s a flyer with more information: OHA algae flyer