Minerva Lake
Burnett County, WisconsinMesotrophic
Minerva Lake sits at the top of the Wisconsin DNR grading rubric with an A, a mark reached by the cleanest lakes in Wisconsin. clarity and phosphorus rate similarly, so there is no obvious single lever to pull on watershed management.
The lake sits in the mesotrophic zone — the band where most well-managed Wisconsin lakes fall. The lake bottoms out at 26 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. Minerva Lake covers 222 acres alongside partial shoreline records — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Minerva Lake ranks 12 of 57 in Burnett County, putting it in the upper tier of locally monitored lakes.
An invasive species record — Chinese Mystery Snail — has been logged at Minerva Lake; Wisconsin DNR maintains the official infested-waters list. Walleye are documented at Minerva Lake, one of 5 fish species on record for the lake. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-09-10. Grade methodology: LakeGrade methodology.
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Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A, Excellent
Good clarity, visible to about 10.5 ft. Phosphorus level: 16.3 µg/L. Trophic State Index: 44.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 10.5 ft | B |
| Phosphorus | 16.3 µg/L | A |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 44 | Mesotrophic |
Moderate nutrients, good water quality
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 26 ft |
| Surface Area | 222 acres |
Fish Species
Click a species to see all Wisconsin and Minnesota lakes where it is found.
→ Best fishing times for Minerva Lake (14-day solunar calendar)
→ Is it safe to eat fish from Minerva Lake? (mercury & PFAS guide)
→ Minerva Lake fishing regulations (limits, seasons, special rules)
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
Water Quality Trend: → Stable
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | -0.15 m/yr | 6 |
| Phosphorus | → Stable | +0.21 µg/L/yr | 6 |
Location
County Ranking
Ranked #12 of 57 lakes in Burnett County
Nearby Lakes in Burnett County
More Wisconsin Lake Rankings
Other Grade A Lakes in Wisconsin
Washington County · Clarity: 11.8 ft
Washington County · Clarity: 12.6 ft
Walworth County · Clarity: 11 ft
Waukesha County · Clarity: 11.3 ft
Walworth County · Clarity: 20.2 ft
Kenosha County · Clarity: 10 ft
Mesotrophic Lakes in Wisconsin
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1995. 3 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
Reservoir Info (USACE NID)
Minerva Lake is a man-made reservoir impounded by the Minerva (completed 1937), built primarily for recreation on the LOON CREEK; gravity-type dam, 14 ft tall and 70 ft long.
- Surface area
- 245 ac
- Normal storage
- 2,000 ac-ft
- Max storage
- 3,000 ac-ft
- Drainage area
- 43 sq mi
- Hazard class
- Low
- Owner
- Burnett County
Source: USACE National Inventory of Dams, NID ID WI00242 · Operator website
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2025-09-10
Monitoring stations: 2