Dean Lake
Wright County, MinnesotaHypereutrophic
Dean Lake grades an F: every scored parameter (clarity and phosphorus) rates poorly, placing it among the most stressed lakes monitored in Minnesota. clarity and phosphorus rate similarly, so there is no obvious single lever to pull on watershed management.
The hypereutrophic status — TSI 75 — reflects sustained heavy nutrient loading from the surrounding watershed and frequent algal pressure. The lake bottoms out at 20 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. The lake's 176 acres and 2.2 miles of shoreline put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Dean Lake ranks 57 of 64 in Wright County — at the lower end of the locally monitored distribution.
Dean 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 Dean Lake, one of 12 fish species on record for the lake. Public access is available — the lake is on the Minnesota PCA public-access list. 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, Minnesota DNR LakeFinder, last sampled 2024-10-02. 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 2.6 ft of visibility. Phosphorus level: 307 µg/L. Trophic State Index: 75.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.6 ft | F |
| Phosphorus | 307 µg/L | F |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 75 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 20 ft |
| Average Depth | 10.4 ft |
| Surface Area | 175.78 acres |
| Shoreline Length | 2.2 mi |
| Littoral Zone | 71% |
| Public Access | Yes |
Fish Species
Click a species to see all Minnesota and Wisconsin lakes where it is found.
→ Best fishing times for Dean Lake (14-day solunar calendar)
→ Is it safe to eat fish from Dean Lake? (mercury & PFAS guide)
→ Dean 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 | +0.31 m/yr | 5 |
| Phosphorus | ↓ Declining | +53.1 µg/L/yr | 5 |
Location
County Ranking
Ranked #57 of 64 lakes in Wright County
Cleaner Lakes Within 30 Miles
Dean Lake holds Grade F. 5 nearby lakes hold higher grades.
- ACharlotte LakeWright County · mi · Two grade letters higher (F → A)
- APulaski LakeWright County · mi · Two grade letters higher (F → A)
- CCrawford LakeWright County · mi · Two grade letters higher (F → C)
- CBeebe LakeWright County · mi · Two grade letters higher (F → C)
- DBuffalo LakeWright County · mi · Higher grade (F → D)
Nearby Lakes in Wright County
More Minnesota Lake Rankings
State Parks Near Dean Lake
Other Grade F Lakes in Minnesota
DNR Fisheries Survey Summary
6 surveys on file from MN DNR Fisheries. Most recent: 2019-07-29 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Black Crappie | 69.51 | 0.25 lb |
| Black Bullhead | 67.48 | 0.45 lb |
| Bluegill | 55.04 | 0.19 lb |
| CNM | 16.01 | — |
| Largemouth Bass | 14.07 | 2.47 lb |
| Yellow Perch | 13.81 | 0.12 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 Crappie
Black Bullhead
Bluegill
Largemouth Bass
From the 2019-07-29 survey
Dean Lake is located 3.5 miles southeast of the city of Buffalo in southeastern Wright County. A public access with limited parking is located on the east side of the lake, adjacent to County Road 14. The lake is 173 acres with an average depth of 10 feet and a maximum depth of 20 feet. The lake has poor water clarity…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Dean Lake. 3 reports on file.
- —Fisheries Lake Survey — DeanFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — DeanFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — DeanPublic Water Access Sites · MN DNR LakeFinder
EPA Impairment Status
Dean 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 MN86-0041-00 · 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: 2024-10-02
Monitoring stations: 1