Luther Burbank Swim Beach Reopened
UPDATE August 27, 2025 - Lab results showed improved water quality at Luther Burbank Beach and met the reopening criteria. The beach has reopened for swimming.
The swim beach at Luther Burbank Park has been closed by Public Health – Seattle & King County, effective immediately, due to high bacteria levels. All park visitors, including children and pets, should obey the posted closure signs and stay out of the water until further notice.
King County regularly conducts water quality testing at swimming areas on Lake Washington and other area lakes to ensure the water is healthy for beachgoers. A recent test indicated higher than normal bacteria levels at the Luther Burbank swim beach and recommended its immediate closure. The beach will remain closed until water quality improves to safe levels.
Public Health will continue to conduct testing and will notify the City when the water is safe to access. Note that only the swim area at Luther Burbank is tested; no testing is performed at the dog park or other water access points.
Public Health tests Luther Burbank and Groveland Beach swim areas on a weekly basis. Groveland Beach bacteria counts are currently within safe levels. The bacteria counts in the water around Mercer Island are typically low. Increased water temperature due to the heat and recent heavy rains pushed contaminants into the lake, likely affecting water quality.
To check the status and test results of Luther Burbank Park and other swimming areas and beaches throughout Seattle and King County, visit the department’s lake swimming webpage. The City of Mercer Island will also update the status of beach access on its website, on social media, and through other channels.