Fish Lake
Hennepin County, MinnesotaMesotrophic
Fish Lake carries a solid B grade — strong on most parameters, with measurements that hold up well across the summer season. The two scored sub-grades — clarity and phosphorus — track close together, so neither one is dragging the average down.
The lake sits in the mesotrophic zone — the band where most well-managed Minnesota lakes fall. Fish Lake reaches 49 ft at its deepest point — typical for Minnesota mid-sized lakes, with seasonal stratification but limited cold-water refuge. Fish Lake covers 238 acres alongside 5.4 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Within Hennepin County's 95 graded waters, Fish Lake sits at rank 7, near the top of the local distribution.
Zebra mussels have been documented at Fish Lake, which alters the filter-feeding balance and can paradoxically increase water clarity while disrupting the food web. The fishery includes walleye among the lake's 16 documented species — a notable draw for Minnesota anglers. Public access is available — the lake is on the Minnesota PCA public-access list. The lake has a long ice-out record — 34 observations on file, with a median ice-out around Apr 5. 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 2024-09-20. 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 8.7 ft. Phosphorus level: 26.3 µg/L. Trophic State Index: 49.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 8.7 ft | C |
| Phosphorus | 26.3 µg/L | B |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 49 | Mesotrophic |
Moderate nutrients, good water quality
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 49 ft |
| Average Depth | 20.3 ft |
| Surface Area | 237.73 acres |
| Shoreline Length | 5.4 mi |
| Littoral Zone | 45% |
| Public Access | Yes |
Fish Species
Click a species to see all Minnesota and Wisconsin lakes where it is found.
→ Best fishing times for Fish Lake (14-day solunar calendar)
→ Is it safe to eat fish from Fish Lake? (mercury & PFAS guide)
→ Fish 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 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.054 m/yr | 5 |
| Phosphorus | ↓ Declining | +1.25 µg/L/yr | 3 |
Ice Season
Historical ice data from Minnesota DNR (36 observations).
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2000-03-08 (2000) | 2018-04-30 (2018) |
| Ice-In | 2006-12-01 (2006) | 2015-12-19 (2015) |
Most recent ice-out: 2020-03-29
Location
County Ranking
Ranked #7 of 95 lakes in Hennepin County
Cleaner Lakes Within 30 Miles
Fish Lake holds Grade B. One nearby lake has a higher grade.
See full comparison →Nearby Lakes in Hennepin County
More Minnesota Lake Rankings
State Parks Near Fish Lake
Other Grade B Lakes in Minnesota
Mesotrophic Lakes in Minnesota
DNR Fisheries Survey Summary
10 surveys on file from MN DNR Fisheries. Most recent: 2024-07-15 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 42.15 | 0.13 lb |
| Black Bullhead | 16.54 | 0.38 lb |
| Largemouth Bass | 4.71 | 1.13 lb |
| Black Crappie | 4.61 | 0.19 lb |
| Northern Pike | 4.55 | 3.42 lb |
| Yellow Perch | 3.95 | 0.14 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.
Bluegill
Black Bullhead
Largemouth Bass
Black Crappie
From the 2024-07-15 survey
Fish Lake is a 238-acre lake with a maximum depth of 49 feet. Fish is located in Maple Grove, in northern Hennepin County. Three Rivers Park District owns and maintains a public access ramp in Fish Lake Regional Park on the southern shore of the lake. Fish is primarily managed for Northern Pike and Largemouth Bass,…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Fish Lake. 3 reports on file.
- —Fisheries Lake Survey — FishFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — FishFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — FishPublic Water Access Sites · MN DNR LakeFinder
EPA Impairment Status
Fish Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN27-0118-00 · 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
Ice data from Minnesota DNR Climate
Most recent sample: 2024-09-20
Monitoring stations: 3