Generally, the lake has been one of the cleanest water bodies around, but sometimes conditions change. For more information on current lake water quality, visit the Lake Health page.

We have a whole page dedicated to the lake water quality. Please visit this page for more information. 

Lake Stevens is a water of the State of Washington and it is regulated by multiple Federal, State, County and Local agencies. The City of Lake Stevens and Snohomish County share the management responsibilities for the lake’s operations. The primary reason for regulating the lake levels is to maintain a summer and fall flow in the lake’s outfall channel for fish habitat.

Table 2 shows the target lake levels that are sought throughout the year.  These elevations were determined based on the ideal elevation to achieve a continuous flow in the outfall channel during the summer and fall months when water flows in streams are typically at their lowest.

Algae growth is a normal process in natural water bodies. Most algae are harmless and aren’t even noticed by lake users, but sometimes algae can grow rapidly or “bloom.” A bloom refers to prolific growth of one or two algae species in the lake. Algae blooms can appear differently. For more information on harmful or potential toxic algae visit Snohomish County Lake Management https://snohomishcountywa.gov/1959/Algae-Toxic-Algae or contact the Environmental Programs Team at environmentalprograms@lakestevenswa.gov 

Lake level is largely driven by precipitation and runoff to the lake. In the summer months, the city maintains a weir (e.g., dam) to increase the water elevation in the summer months for recreation. Please refer to the Lake Management page to see the current and the historical levels of the lake. For more information regarding weir management, please refer to the Lake Level Management Plan.

Don’t feed birds or ducks near swimming areas

• Waterfowl are part of the parasite's lifecycle. Feeding them encourages them to stay, increasing the chance of parasite contamination.

Rinse off and dry quickly

• Towel off immediately after getting out of the water. Rubbing your skin briskly with a towel may remove parasites before they burrow in.
• Rinse with clean water if possible (not just lake water).

Apply water-repellent creams or lotions

• Barrier creams like petroleum jelly or waterproof sunscreens may help prevent parasites from reaching your skin.

Avoid early morning swims

• Cercariae (the parasites) tend to be more active in the morning and when the water is warmer.

Swim in deeper water

• Parasites are mostly found in shallow, calm water. Swimming farther from shore reduces risk.

There are native, healthy "weeds" that provide food and habitat for wildlife, and non-native, invasive plants. For more information, please visit Snohomish County's website at Aquatic Plant Identification | Snohomish County, WA - Official Website, or contact environmentalprograms@lakestevenswa.gov.