Okabena Lake

Okabena Lake earns an F: 167 µg/L of phosphorus and clarity at 3.3 ft signal heavy nutrient loading from the surrounding watershed. With clarity and phosphorus scored, the sub-grades cluster within a letter of each other, pointing to stable conditions rather than one specific stressor.

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. Okabena Lake reaches 16 ft at its deepest point — typical for Minnesota mid-sized lakes, with seasonal stratification but limited cold-water refuge. Okabena Lake covers 776 acres alongside 6.5 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Among the 4 graded lakes in Nobles County, Okabena Lake sits at rank 2, above the county median.

No invasive species are currently listed at Okabena Lake — the lake remains off the Minnesota infested-waters roster. The fishery includes walleye among the lake's 18 documented species — a notable draw for Minnesota anglers. Public access is available — the lake is on the Minnesota PCA public-access list. Ice-out has been recorded 22 times at Okabena Lake, with a median around Mar 26. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.