Spring Lake

Spring Lake grades an F: water clarity, phosphorus, and chlorophyll-a all rate poorly, placing it among the most stressed lakes monitored in Wisconsin. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

A TSI in the eutrophic range signals a lake doing what nutrient-loaded waters do — supporting an active algal community at the cost of clear water. The lake bottoms out at 22 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. At 60 acres, Spring Lake sits below the Wisconsin median: a small water where shoreline activity has an outsized effect on water quality. Within the 9 graded lakes of Ozaukee County, Spring Lake sits at rank 7, near the bottom of the county list.

Spring Lake carries an invasive watermilfoil record — boat-launch decontamination and shoreline care matter more here than at uninfested lakes. The fishery is bass-led, with 3 documented species across the lake's records. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.