Eagle Lake
Blue Earth County, MinnesotaLimited DataHypereutrophic
Eagle Lake earns an F: phosphorus readings still being added and clarity at 1.0 ft signal heavy nutrient loading from the surrounding watershed.
The hypereutrophic status — TSI 77 — reflects sustained heavy nutrient loading from the surrounding watershed and frequent algal pressure. Eagle Lake is a shallow lake at 9 ft maximum depth, which means it warms quickly, mixes constantly, and amplifies nutrient inputs. Eagle Lake covers 898 acres alongside 9.8 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Eagle Lake ranks 4 of 9 in Blue Earth County — solidly in the upper half of the local distribution.
Eurasian watermilfoil is established at Eagle Lake, which can dampen recreational access and pressure the native plant community. The state fisheries records do not list documented species for Eagle Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. A documented public access point at Eagle 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 2023-09-19. Grade methodology: LakeGrade methodology.
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Swimming Safety
Avoid swimming, very poor water quality, potential algae toxins
Water Quality Grade: F, Very Poor
Very murky, less than 1 ft of visibility. Trophic State Index: 77.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1 ft | F |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 77 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 9 ft |
| Surface Area | 898.23 acres |
| Shoreline Length | 9.8 mi |
| Littoral Zone | 80% |
| Public Access | Yes |
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
Location
County Ranking
Ranked #4 of 9 lakes in Blue Earth County
Cleaner Lakes Within 30 Miles
Eagle Lake holds Grade F. 2 nearby lakes hold higher grades.
Nearby Lakes in Blue Earth County
More Minnesota Lake Rankings
State Parks Near Eagle Lake
Other Grade F Lakes in Minnesota
Compare Eagle Lake With Nearby Lakes
DNR Fisheries Survey Summary
4 surveys on file from MN DNR Fisheries. Most recent: 2023-04-19 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Black Bullhead | 273.88 | 0.11 lb |
| Black Crappie | 5.25 | 0.26 lb |
| Walleye | 4.60 | 1.36 lb |
| Common Carp | 3.89 | 2.71 lb |
| Northern Pike | 3.54 | 3.35 lb |
| Freshwater Drum | 2.40 | 1.1 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.
Black Bullhead
Black Crappie
Walleye
Common Carp
From the 2023-04-19 survey
Two trap nets were set on 19 April 2023 to assess winterkill. Trap nets were set on the north shore, near the inlet which is an area fish have traditionally congregated. Black Bullhead was the only species sampled. Dead Walleye and Common Carp were observed along the shoreline.
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Eagle Lake. 3 reports on file.
- —Fisheries Lake Survey — EagleFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — EagleFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — EaglePublic Water Access Sites · MN DNR LakeFinder
EPA Impairment Status
Eagle 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 MN07-0060-01 · Official waterbody report · Matched by proximity (1.05 km)
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: 2023-09-19
Monitoring stations: 1