Minerva Lake
Clearwater County, MinnesotaMesotrophic
Minerva Lake comes in at a B on the grading rubric — a respectable showing for a Minnesota lake of its size and depth. With clarity and phosphorus scored, the sub-grades cluster within a letter of each other, pointing to stable conditions rather than one specific stressor.
The lake sits in the mesotrophic zone — the band where most well-managed Minnesota lakes fall. The lake bottoms out at 16 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. The lake's 230 acres and 2.8 miles of shoreline put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Within the 40 graded lakes of Clearwater County, Minerva Lake sits at rank 31, near the bottom of the county list.
Minerva Lake has no invasive species recorded in Minnesota state databases as of 2024, though prevention practices still apply at all access points. Walleye are documented at Minerva Lake, one of 11 fish species on record for the lake. A documented public access point at Minerva 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, Minnesota DNR LakeFinder, last sampled 2024-09-10. Grade methodology: LakeGrade methodology.
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Swimming Safety
Good for swimming, clear water with low algae levels
Water Quality Grade: B, Good
Moderate clarity, visible to about 7.3 ft. Phosphorus level: 26 µg/L. Trophic State Index: 50.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 7.3 ft | C |
| Phosphorus | 26 µg/L | B |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 50 | Mesotrophic |
Moderate nutrients, good water quality
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 16 ft |
| Average Depth | 7.9 ft |
| Surface Area | 230.02 acres |
| Shoreline Length | 2.8 mi |
| Littoral Zone | 95% |
| Public Access | Yes |
Fish Species
Click a species to see all Minnesota and Wisconsin 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)
Water Quality Trend: → Stable
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.104 m/yr | 5 |
| Phosphorus | ↓ Declining | +1.6 µg/L/yr | 5 |
Location
County Ranking
Ranked #31 of 40 lakes in Clearwater County
Cleaner Lakes Within 30 Miles
Minerva Lake holds Grade B. 4 nearby lakes hold higher grades.
- ALong LakeClearwater County · mi · Higher grade (B → A)
- ABig Lasalle LakeClearwater County · mi · Higher grade (B → A)
- BLasalle LakeHubbard County · mi · Higher overall water quality score
- BWalker Brook LakeClearwater County · mi · Higher overall water quality score
Nearby Lakes in Clearwater County
More Minnesota Lake Rankings
State Parks Near Minerva Lake
Other Grade B Lakes in Minnesota
Mesotrophic Lakes in Minnesota
DNR Fisheries Survey Summary
7 surveys on file from MN DNR Fisheries. Most recent: 2016-06-27 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Yellow Perch | 29.23 | 0.27 lb |
| Black Bullhead | 23.15 | 0.6 lb |
| Brown Bullhead | 10.09 | 0.87 lb |
| Bluegill | 7.70 | 0.45 lb |
| Pumpkinseed | 6.43 | 0.24 lb |
| Largemouth Bass | 5.14 | 1.55 lb |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
Length Distributions
Number of fish caught at each inch class in the most recent survey that recorded lengths. Red dashed line marks an approximate trophy threshold for that species.
Yellow Perch
Black Bullhead
Brown Bullhead
Bluegill
From the 2016-06-27 survey
Lake Minerva is a 230-acre lake with a maximum depth of 16 feet located 12 miles south of Bagley in Clearwater County. There is a DNR public water access located on the southeast shore of the lake with an earthen ramp and parking for about 8 trucks/trailers. Lake Minerva is managed for Walleye, Black Crappie, and…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Minerva Lake. 4 reports on file.
- —Fisheries Lake Survey — MinervaFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Minerva (1698)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — MinervaFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — MinervaPublic Water Access Sites · MN DNR LakeFinder
Reservoir Info (USACE NID)
Minerva Lake is a man-made reservoir impounded by the Upper Rice Lake (completed 1968), built primarily for fish and wildlife pond on the Wild Rice River; gravity-type dam, 7 ft tall and 26 ft long.
- Normal storage
- 11,160 ac-ft
- Max storage
- 14,880 ac-ft
- Drainage area
- 14.3 sq mi
- Hazard class
- Low
- Owner
- MNDNR-Wildlife
Source: USACE National Inventory of Dams, NID ID MN00231 · Operator website · Matched by proximity (0.82 km)
EPA Impairment Status
Minerva Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN15-0079-00 · Official waterbody report
Data Sources
Water quality data from the EPA Water Quality Portal
Impairment status from EPA ATTAINS 303(d) database
Grading methodology based on Metropolitan Council standards
Lake details from Minnesota DNR LakeFinder
Most recent sample: 2024-09-10
Monitoring stations: 1