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LakeQuality

Dean Lake

F
Grade F — Algae-prone
Algae-prone · #44 of 51 lakes in the county · 4.3 ft clear · Hypereutrophic · 176 acres · from D
Hypereutrophic

Dean Lake in Wright County, Minnesota has a water quality grade of F (Algae-prone). Water clarity: 4.3 ft visibility. Phosphorus: 324 µg/L. Chlorophyll-a (algae): 39.2 µg/L. Maximum depth: 20 ft. Surface area: 175.78 acres.

Clarity
4.3 ft
Typical in August
71°F
Max depth
20 ft
Area
176 acres
Type
Hypereutrophic
Trend
Improving
Public access
Yes

Grade F measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Dean Lake

Next lake in Wright County

CCrawford Lake5.9 ft clear · Wright CountyView →
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Dean Lake is a 176-acre highly nutrient-loaded hypereutrophic lake in Wright County, Minnesota with a maximum depth of 20 feet (10-foot average). Water quality is graded F based on 2 sampling years through 2025. Overall water quality is improving over recent sampling years. The lake supports 12 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing. Compared to the 50 other monitored lakes in Wright County, Dean Lake ranks #44 for water quality.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-29. Grade methodology: LakeGrade methodology.

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Swimming Safety

Grade only

Algae risk

Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.

Algae and nutrients are often high — check current advisories before swimming. Skip the water if you see scum or a paint-like bloom

Compare the safest swimming lakes near Minneapolis

Get alerts for Dean Lake

Water Quality Grade: F (Algae-prone)

Murky, only visible to about 4.3 ft. Phosphorus level: 324 µg/L. Chlorophyll-a: 39.2 µg/L. Trophic State Index: 70.

MetricValueGrade
Water Clarity (Secchi Depth)4.3 ftNot graded
Phosphorus324 µg/LPoor
Chlorophyll-a (Algae)39.2 µg/LPoor
Trophic State Index (TSI)70Hypereutrophic

Very high nutrients, dense algae, poor clarity

Where to stay near Dean Lake

Compare lakeside cabins, hotels, and vacation rentals near Dean Lake in Wright County, Minnesota — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Dean Lake are listed below.

Top-rated places to stay near Dean Lake

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

Planning a whole trip? See where to stay at Minnesota’s top lakes →

Water Temperature

Dean Lake typically sits around 71°F at the surface in August. Summer average is about 70°F. Usually warmest in Jul (about 72°F) and coldest in May (about 60°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
May
60°
Jun
66°
Jul
72°
Aug
71°
Sep
70°
Oct
66°
Nov
Dec

Typical surface water temperature by month, from 162 field readings (20162025) via the EPA Water Quality Portal. See the full Dean Lake water temperature breakdown →

Lake Details

CharacteristicValue
Maximum Depth20 ft
Average Depth10.4 ft
Surface Area176 acres
Shoreline Length2.2 mi
Littoral Zone71%
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
3 sq mi
Elevation
925 ft

Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Dean LakePublic

Fish Species

Click a species to see every graded lake where it is documented.

Fishing Dean Lake

DNR Fisheries Survey Summary

6 surveys on file from MN DNR Fisheries. Most recent: 2019-07-29 (Standard Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
Black Crappie69.510.25 lb
Black Bullhead67.480.45 lb
Bluegill55.040.19 lb
CNM16.01
Largemouth Bass14.072.47 lb
Yellow Perch13.810.12 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

42 fish · 111 in · 2019-07-29
840trophy 101234567891011

Black Bullhead

80 fish · 815 in · 2019-07-29
4121089101112131415

Bluegill

167 fish · 37 in · 2019-07-29
6533034567

Largemouth Bass

74 fish · 620 in · 2019-07-29
21110trophy 2068101214161820

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…

Source: MN DNR LakeFinder Fisheries Lake Survey

DNR Reports & Resources

Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Dean Lake. 3 reports on file.

These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).

Based on 6 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Improving+0.377 m/yr6
Phosphorus Declining+38.43 µg/L/yr6
Chlorophyll-a Improving-22.72 µg/L/yr6
See year-by-year chart →

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

Nutrients (phosphorus, nitrogen)

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit MN86-0041-00 · Official waterbody report

Regulated Pollution Sources Nearby

1 EPA-permitted facility operate within about 5 miles of Dean Lake under Clean Water Act (NPDES) discharge permits.

  • Dickinson Converter Station
    Wright County · 1.3 mi away · NPDES MN0049077

Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.

County Ranking

Ranked #44 of 51 lakes in Wright County

Nearby Lakes With Higher Grades

Dean Lake holds Grade F. 3 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.

See full comparison →

Nearby Lakes in Wright County

Frequently asked questions about Dean Lake

What is the water quality grade for Dean Lake?

Dean Lake in Wright County, Minnesota has a water quality grade of F (Algae-prone). Water clarity: 4.3 ft visibility. Phosphorus: 324 µg/L. Chlorophyll-a (algae): 39.2 µg/L. Maximum depth: 20 ft. Surface area: 175.78 acres.

Is Dean Lake safe to swim in?

Algae and nutrients are often high — check current advisories before swimming. Skip the water if you see scum or a paint-like bloom. Dean Lake has a water quality grade of F (Algae-prone). Algae concentration (chlorophyll-a) is 39.2 µg/L. Always check local health department advisories before swimming.

What is the water temperature of Dean Lake?

Dean Lake typically sits around 71°F at the surface in August, from 162 EPA Water Quality Portal field readings (2016–2025). That is a typical value for the month, not a live reading.

How deep is Dean Lake?

Dean Lake has a maximum depth of 20 feet and an average depth of 10.4 feet. The lake covers 175.78 acres.

What fish are in Dean Lake?

Fish species found in Dean Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, common carp, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, walleye, yellow bullhead. Dean Lake is located in Wright County, Minnesota.

Are there boat ramps on Dean Lake?

Dean Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Dean Lake. Public access is listed as yes.

Hypereutrophic Lakes in Minnesota

Where this data comes from

162 measurements from 2 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Minnesota Pollution Control Agency - Ambient Surface WaterMNPCA162 samples · 2020–2025

Analytical methods

  • Field measurement/observation, generic method
  • Phosphorus by Two Reagent Colorimetry
  • 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (2)

Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.

Other records on this page

Impairment status from EPA ATTAINS 303(d) database

Regulated discharger data from EPA ECHO (ICIS-NPDES)

Lake size & watershed from HydroLAKES (HydroSHEDS)

Lake details from Minnesota DNR LakeFinder

Named boat-access points from the USGS National Boat Ramps inventory