Washington Lake

The LakeGrade rubric puts Washington Lake at a C: clarity at 4.5 ft, 33 µg/L of phosphorus, and a TSI of 55 signal an intermediate trophic state. The two scored sub-grades — clarity and phosphorus — track close together, so neither one is dragging the average down.

A TSI in the eutrophic range signals a lake doing what nutrient-loaded waters do — supporting an active algal community at the cost of clear water. Washington Lake reaches 17 ft at its deepest point — typical for Minnesota mid-sized lakes, with seasonal stratification but limited cold-water refuge. With 2,438 acres of surface and 10.0 miles of shoreline, Washington Lake is a large water by Minnesota standards — recreational pressure is spread across a long shoreline. Among the 23 graded lakes in Meeker County, Washington Lake sits at rank 8, above the county median.

Zebra mussels have been documented at Washington Lake, which alters the filter-feeding balance and can paradoxically increase water clarity while disrupting the food web. Walleye are documented at Washington Lake, one of 18 fish species on record for the lake. Public access is available — the lake is on the Minnesota PCA public-access list. Ice-out has been recorded 6 times at Washington Lake, with a median around Apr 8. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.