Eagle Lake

Eagle Lake earns an F: phosphorus readings still being added and clarity at 1.0 ft signal heavy nutrient loading from the surrounding watershed. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

A TSI above 70 puts Eagle Lake in hypereutrophic territory: visible blooms are common, and clarity rarely climbs even in early summer. At only 9 ft deep, Eagle Lake is shallow — wind keeps the water column mixed and sediment resuspension drives phosphorus levels harder to manage. Eagle Lake covers 898 acres alongside 9.8 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Among the 9 graded lakes in Blue Earth County, Eagle Lake sits at rank 4, above the county median.

Eagle Lake carries an invasive watermilfoil record — boat-launch decontamination and shoreline care matter more here than at uninfested lakes. The state fisheries records do not list documented species for Eagle Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. Public access is available — the lake is on the Minnesota PCA public-access list. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.