Piersons Lake

Piersons Lake sits at the top of the Minnesota PCA grading rubric with an A, a mark reached by the cleanest lakes in Minnesota. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

Mesotrophic conditions dominate at Piersons Lake: enough nutrients for a healthy fishery, not so much that algal blooms become a chronic problem. A maximum depth of 40 ft puts Piersons Lake in the middle of Minnesota's depth distribution. The lake's 267 acres and 4.0 miles of shoreline put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Among the 40 graded lakes in Carver County, Piersons Lake ranks 3 — in the top quartile locally.

Zebra mussel presence at Piersons Lake means the lake's clarity numbers carry an asterisk — filtered water is not the same as nutrient-poor water. The fishery includes walleye alongside the lake's other 14 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 logged at Piersons Lake more than two dozen times, putting the median around Apr 5 — a useful baseline for tracking climate trends. 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.