Hidden Valley Lake

The LakeGrade rubric puts Hidden Valley Lake at a C: clarity at 5.0 ft, 45 µg/L of phosphorus, and a TSI of 56 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. A maximum depth of 18 ft puts Hidden Valley Lake in the middle of Wisconsin's depth distribution. At 26 acres, Hidden Valley Lake sits below the Wisconsin median: a small water where shoreline activity has an outsized effect on water quality. Hidden Valley Lake sits at rank 2 of 3 in Lafayette County, in the lower half of the local distribution.

No invasive species are currently listed at Hidden Valley Lake — the lake remains off the Wisconsin infested-waters roster. The state fisheries records do not list documented species for Hidden Valley Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. 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.