Carstens Lake

The LakeGrade rubric puts Carstens Lake at a C: clarity at 17.2 ft, 93 µg/L of phosphorus, and a TSI of 53 signal an intermediate trophic state. Phosphorus is the parameter holding the grade back — runoff from the surrounding watershed appears to keep nutrient levels elevated through the summer.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. The lake's surface area is not consistently recorded across state datasets — physical context remains partial. Within the 18 graded lakes of Manitowoc County, Carstens Lake sits at rank 15, near the bottom of the county list.

Carstens Lake has no invasive species recorded in Wisconsin state databases as of 2025, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Carstens Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.