Eagle Spring Lake

Eagle Spring Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Waukesha County. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.

A TSI near 42 places Eagle Spring Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. Eagle Spring Lake is a shallow lake at 8 ft maximum depth, which means it warms quickly, mixes constantly, and amplifies nutrient inputs. The lake's 279 acres and partial shoreline records put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Eagle Spring Lake sits at rank 36 of 48 in Waukesha County, in the lower half of the local distribution.

Zebra mussels have been documented at Eagle Spring Lake, which alters the filter-feeding balance and can paradoxically increase water clarity while disrupting the food web. Bass fishing is part of the appeal: the species list runs to 3, anchored by largemouth and/or smallmouth bass. 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.