Lake Keesus

On the LakeGrade scale Lake Keesus grades a B, with clarity at 9.2 ft and 16 µg/L of phosphorus placing it above the Wisconsin median. Clarity is the limiting factor — phosphorus is reasonable but suspended particles or algal cells keep water transparency below Wisconsin norms.

Mesotrophic conditions dominate at Lake Keesus: enough nutrients for a healthy fishery, not so much that algal blooms become a chronic problem. Lake Keesus reaches 42 ft at its deepest point — typical for Wisconsin mid-sized lakes, with seasonal stratification but limited cold-water refuge. Lake Keesus covers 235 acres alongside partial shoreline records — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Lake Keesus sits at rank 25 of 45 in Waukesha County, in the lower half of the local distribution.

Zebra mussel presence at Lake Keesus 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 4 documented species — a notable draw for Wisconsin anglers. Public access is available — the lake is on the Wisconsin DNR public-access list. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.