Plainfield Lake

Plainfield Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Waushara County. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

The lake's low TSI puts it in oligotrophic territory — the cleanest of the four trophic classes, but also the most vulnerable to nutrient-driven shifts. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. Plainfield Lake is small — 29 acres alongside partial shoreline records — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Plainfield Lake sits at rank 17 of 30 in Waushara County, in the lower half of the local distribution.

Plainfield Lake has at least one documented invasive species (Banded Mystery Snail), so boaters and anglers should observe clean-drain-dry steps when leaving the lake. The lake's fish records list 1 species — a varied community without one dominant gamefish. Public access is available — the lake is on the Wisconsin DNR public-access list. 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.