Ocauchee Lake

On the LakeGrade scale Ocauchee Lake grades a B, with clarity at 6.6 ft and 18 µg/L of phosphorus placing it above the Wisconsin median. Secchi readings are the weakest of the three parameters, suggesting suspended sediment or algal biomass dominates the optical signal.

The lake sits in the mesotrophic zone — the band where most well-managed Wisconsin lakes fall. The lake's 90 ft maximum depth is in the upper tier for Wisconsin — deep enough for cold-water fish to find refuge in summer. At 1,210 acres, Ocauchee Lake is one of the larger lakes in Waukesha County, with partial shoreline records supporting multiple distinct use patterns. Ocauchee Lake ranks 44 of 48 in Waukesha County — at the lower end of the locally monitored distribution.

Zebra mussels have been documented at Ocauchee Lake, which alters the filter-feeding balance and can paradoxically increase water clarity while disrupting the food web. Walleye are documented at Ocauchee Lake, one of 6 fish species on record for the lake. A documented public access point at Ocauchee Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. 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.