Lake Sammamish is a mesotrophic lake in King County, Washington. Water quality is graded B based on 1 sampling years through 2021. Compared to the 5 other monitored lakes in King County, Lake Sammamish ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, Washington DNR, last sampled 2021-07-06. Grade methodology: LakeGrade methodology.
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Swimming Safety
Good for swimming, clear water with low algae levels
Water Quality Grade: B, Good
Good clarity, visible to about 11.5 ft. Trophic State Index: 42.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 11.5 ft | B |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 42 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Lake Sammamish
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Fishing Lake Sammamish
Location
County Ranking
Ranked #3 of 6 lakes in King County
Nearby Lakes in King County
Explore Lake Sammamish across LakeGrade
More Washington Lake Rankings
Other Grade B Lakes in Washington
Mesotrophic Lakes in Washington
More records, surveys & data sources
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2021-07-06
Monitoring stations: 1