Lower Phantom Lake

Lower Phantom Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Waukesha County. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

A TSI value of 39 puts Lower Phantom Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. Lower Phantom Lake is a shallow lake at 12 ft maximum depth, which means it warms quickly, mixes constantly, and amplifies nutrient inputs. At 373 acres, Lower Phantom Lake fits the Wisconsin median for monitored lakes, with partial shoreline records. Among the 48 graded lakes in Waukesha County, Lower Phantom Lake sits at rank 24, above the county median.

Lower Phantom Lake is on the Wisconsin infested-waters list for zebra mussels — boaters should follow clean-drain-dry protocols when moving gear to or from the lake. The fishery is bass-led, with 3 documented species across the lake's records. A documented public access point at Lower Phantom Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.