Muskego Lake
Waukesha County, WisconsinLimited DataEutrophic
Muskego Lake earns a C — middle-of-the-pack water quality, with one or two parameters dragging the average down from a stronger grade. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.
At a TSI of 63, Muskego Lake reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. A maximum depth of 23 ft puts Muskego Lake in the middle of Wisconsin's depth distribution. At 2,194 acres, Muskego Lake is one of the larger lakes in Waukesha County, with partial shoreline records supporting multiple distinct use patterns. Within the 48 graded lakes of Waukesha County, Muskego Lake sits at rank 46, near the bottom of the county list.
Eurasian watermilfoil has been documented at Muskego Lake, requiring shoreline management to keep dense mats from crowding native vegetation. The fishery is bass-led, with 3 documented species across the lake's records. A documented public access point at Muskego 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.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2022-05-11. Grade methodology: LakeGrade methodology.
Swimming Safety
Generally safe for swimming, moderate water quality
Water Quality Grade: C, Fair
No clarity data. Phosphorus level: 59.4 µg/L. Trophic State Index: 63.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No data | |
| Phosphorus | 59.4 µg/L | C |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 63 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 23 ft |
| Surface Area | 2.2K acres |
| Public Access | Yes |
Fish Species
Click a species to see all Wisconsin and Minnesota lakes where it is found.
→ Best fishing times for Muskego Lake (14-day solunar calendar)
→ Is it safe to eat fish from Muskego Lake? (mercury & PFAS guide)
→ Muskego Lake fishing regulations (limits, seasons, special rules)
Invasive Species
Water Quality Trend: ↓ Declining
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Phosphorus | ↓ Declining | +91.2 µg/L/yr | 2 |
Recreation & Access
Location
County Ranking
Ranked #46 of 48 lakes in Waukesha County
Cleaner Lakes Within 30 Miles
Muskego Lake holds Grade C. 2 nearby lakes hold higher grades.
- ADenoon LakeWaukesha County · 2.1 mi · Two grade letters higher (C → A)
- ATichigan LakeRacine County · 4.8 mi · Two grade letters higher (C → A)
Nearby Lakes in Waukesha County
More Wisconsin Lake Rankings
State Parks Near Muskego Lake
Other Grade C Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. 32 stations on file (most recent sample 2023).
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: 2022-05-11
Monitoring stations: 1