July 24, 2025

The city is aware of the clams washing up on the shores around the lake. We have collected data and are actively looking into this. Thank you for your patience and we will provide an update early next week. 

July 29, 2025 Update

Last week, many invasive Asian clams washed up along the shoreline. City staff investigated the event and looked at water quality parameters as well as the recent, July 22nd, aquatic plant treatment. While a definitive cause has not been confirmed, current data and scientific literature suggest high water temperatures were likely a significant factor. Water temperatures recorded at North Cove Police Dock reached almost 80°F the week prior. High water temperatures have been documented to cause heat stress in these shallow-dwelling clams. While the event may lead to short-term nutrient spikes, there’s no risk to public health, and lake water remains safe for recreation.

If you notice unusual algae, odors, or water discoloration, please contact Lake Stevens Public Works at 425-622-9403. Monthly lake testing is ongoing to monitor conditions. For a full report on the investigation into the event, visit our Lake Health webpage for a report included in the supporting documents section of the webpage: https://lakestevenswa.civilspace.io/en/projects/lake-health 

For additional information, please contact the City of Lake Stevens Environmental Programs Division at EnvironmentalPrograms@LakeStevensWA.gov or visit our webpage on the city's website: https://lakestevenswa.gov/746/Lake-Management