Green Lake visitors are being urged to exercise caution as Public Health Seattle & King County has issued a health advisory due to elevated cyanotoxin levels detected in recent water tests. This advisory affects Seattle, just a short drive from Snoqualmie, Washington, where residents and visitors alike enjoy outdoor recreation. Officials have begun installing warning signs around the popular recreational area to alert visitors about the potential dangers associated with water contact. The health department emphasized that the advisory will remain in effect until the harmful algae naturally dissipates and water safety can be confirmed through two consecutive tests showing toxin levels have returned to acceptable ranges.
The cyanotoxins, produced by certain types of blue-green algae that can flourish during warmer weather conditions, pose significant health risks to both humans and animals. While visible algae blooms often appear as green or blue-green scum on the water’s surface, toxins can persist even when visible signs have disappeared. Health officials are regularly monitoring the lake’s conditions and will update the public when it’s deemed safe to resume normal recreational activities. Until then, residents are advised to avoid water contact and to prevent children and pets from accessing the lake.
Health officials are particularly concerned about the risk to dogs, as canines face a substantially higher danger from exposure to the toxic algae present in Green Lake. According to the health department’s alert, “Dogs are especially vulnerable to cyanotoxins, which can be lethal at levels harmless to humans.” This heightened vulnerability stems from dogs’ tendency to drink lake water while swimming and to lick their fur afterward, potentially ingesting concentrated amounts of the toxins that can rapidly lead to severe illness or death.
Green Lake is not the only local waterway currently under an advisory. At least five other popular recreational spots across King County have similar warnings in effect due to algae or bacterial contamination concerns. These include Gene Coulon Beach in Renton, both Houghton Beach and Juanita Beach in Kirkland, Lake Wilderness Beach, and Newcastle Beach. The widespread nature of these advisories underscores the regional impact of current environmental conditions on water quality. Residents seeking up-to-date information about the status of these advisories are encouraged to visit the Public Health Seattle & King County website for the latest test results and recommendations.
