Pine Lake
Waukesha County, WisconsinOligotrophic
Pine 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.
Trophically, Pine Lake reads as oligotrophic — nutrient-poor, clear, and ecologically more sensitive to disturbance than richer lakes. Pine Lake is unusually deep for Wisconsin at 85 ft, which buffers the lake against summer warming and helps the deep water stay oxygenated. The lake's 711 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. Pine Lake ranks 5 of 48 in Waukesha County, putting it in the upper tier of locally monitored lakes.
Zebra mussels have been documented at Pine Lake, which alters the filter-feeding balance and can paradoxically increase water clarity while disrupting the food web. Walleye are documented at Pine Lake, one of 5 fish species on record for the lake. 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.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-08-26. Grade methodology: LakeGrade methodology.
Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A, Excellent
Crystal clear, you can see 82 ft down. Phosphorus level: 11.9 µg/L. Trophic State Index: 27.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 82 ft | A |
| Phosphorus | 11.9 µg/L | A |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 27 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 85 ft |
| Surface Area | 711 acres |
| Public Access | Yes |
Fish Species
Click a species to see all Wisconsin and Minnesota lakes where it is found.
→ Best fishing times for Pine Lake (14-day solunar calendar)
→ Is it safe to eat fish from Pine Lake? (mercury & PFAS guide)
→ Pine Lake fishing regulations (limits, seasons, special rules)
Invasive Species
Water Quality Trend: ↑ Improving
Based on 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +1.839 m/yr | 7 |
| Phosphorus | ↑ Improving | -1.19 µg/L/yr | 4 |
Recreation & Access
Location
County Ranking
Ranked #5 of 48 lakes in Waukesha County
Nearby Lakes in Waukesha County
More Wisconsin Lake Rankings
State Parks Near Pine Lake
Other Grade A Lakes in Wisconsin
Walworth County · Clarity: 19 ft
Washington County · Clarity: 12 ft
Kenosha County · Clarity: 10.1 ft
Washington County · Clarity: 12.5 ft
Walworth County · Clarity: 10.8 ft
Walworth County · Clarity: 11 ft
Oligotrophic Lakes in Wisconsin
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 2008. 3 stations on file (most recent sample 2026).
Fish Species (DNR-rated)
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Fish and recreation data from Wisconsin DNR Lakes
Most recent sample: 2025-08-26
Monitoring stations: 1