Cottonwood Lake
Cottonwood County, Minnesota155 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Cottonwood Lake. Here is what has been measured.
- Eutrophic
- Impaired · Impaired biota (cause unknown)
- 10 ft max depth
- Public access
- Limited data
Cottonwood Lake in Cottonwood County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 2.1 ft visibility. Phosphorus: 60 µg/L. Chlorophyll-a (algae): 18.2 µg/L. Maximum depth: 10 ft. Surface area: 154.97 acres.
Minnesota DNR's Standard Survey on August 19, 2024 caught 3.67 walleye per gill net at Cottonwood Lake. DNR survey details →
Cottonwood Lake is a 155-acre productive, nutrient-rich eutrophic lake in Cottonwood County, Minnesota with a maximum depth of 10 feet (8-foot average). Overall water quality is improving over recent sampling years. The lake supports 15 documented fish species including bigmouth buffalo, black bullhead, and black crappie. Public access is available with 1 public boat landing. Compared to the 2 other monitored lakes in Cottonwood County, Cottonwood Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-03. Methodology: how these readings are compared.
What Cottonwood Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Fishing15 species recorded
Swimming conditions
Readings onlyLimited data
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Cottonwood Lake is listed impaired under Clean Water Act §303(d) (IR 5) for impaired biota (cause unknown). Check local advisories before you swim.
Whether Cottonwood Lake is safe to swim in today is a call for the Minnesota Pollution Control Agency and the Minnesota DNR and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Cottonwood Lake
These are the measurements Minnesota PCA publishes for Cottonwood Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 2.1 ft of visibility. Phosphorus 60 µg/L. Chlorophyll-a 18.2 µg/L. TSI 63.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 2.1ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 60µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 18.2µg/L | Fair GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 63 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Cottonwood Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Cottonwood Lake typically sits around 73°F at the surface in September. Summer average is about 77°F. Usually warmest in Jul (about 82°F) and coldest in Jun (about 73°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (73°F) to its warmest (82°F).
Typical surface water temperature by month, from 20 field readings (2022–2025) via the EPA Water Quality Portal. See the full Cottonwood Lake water temperature breakdown →
Minnesota DNR's Standard Survey on August 19, 2024 caught 3.67 walleye per gill net at Cottonwood Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Cottonwood Lake’s water-quality measurements separately, and the water-quality trend over 2 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
9 surveys on file from MN DNR Fisheries. Most recent: 2024-08-19 (Standard Survey).
9 surveys on file · most recent 2024-08-19 (Standard Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Black Bullhead | 92.97 | 5–11 in 2024-08-19 | 0.15 lb |
| Black Crappie | 11.89 | 5–10 in 2024-08-19 | 0.25 lb |
| Yellow Perch | 11.43 | 5–10 in 2024-08-19 | 0.15 lb |
| Bluegill | 7.26 | 3–8 in 2024-08-19 | 0.23 lb |
| Largemouth Bass | 5.54 | 16 in 2024-08-19 | 2.68 lb |
CPUE = catch per unit effort, fish caught per net per set in a standardised survey. It measures abundance, not size, and is not a weekly bite report.
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
Yellow Perch
Bluegill
From the 2024-08-19 survey
Cottonwood Lake is a small shallow lake, 155 acres and 11 feet max depth, located in the City of Windom in Cottonwood County. While there are many concerns about water quality and water quantity in Cottonwood Lake, the lake remains resilient and has some decent fishing at times. Cottonwood Lake is managed primarily…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Cottonwood Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — CottonwoodFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — CottonwoodFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — CottonwoodPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
10 ft
Average depth
8 ft
Surface area
155 acres
Shoreline
3.5 mi
Littoral zone
100%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
2 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,362 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Cottonwood LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Cottonwood Lake
Compare lakeside cabins, hotels, and vacation rentals near Cottonwood Lake in Cottonwood 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 readings cover nutrients and algae, not lodging. Cabins and rentals around Cottonwood Lake are listed below.
Top-rated places to stay near Cottonwood Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
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 →
Follow Cottonwood Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Cottonwood Lake
Water quality readings over time
2 seasons of samples on record (2022–2025). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Worsening2 years
Phosphorus
Improving-9.5 µg/L/yr2 years
Chlorophyll-a
Improving-1.43 µg/L/yr2 years
EPA Impairment Status
Cottonwood Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Aquatic life.
Source: EPA ATTAINS assessment unit MN17-0022-00 · Official waterbody report
Regulated Pollution Sources Nearby
2 EPA-permitted facilities operate within about 5 miles of Cottonwood Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger. 1 facility has a reported Clean Water Act violation in the past three years.
- Windom WwtpWindom · 1.2 mi away · NPDES MN0022217MajorRecent violation
- Pm WindomWindom · 2.1 mi away · NPDES MN0067482
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.
Nearby Lakes in Cottonwood County
Frequently asked questions about Cottonwood Lake
Where is Cottonwood Lake?
- Cottonwood Lake is a lake in Cottonwood County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Cottonwood Lake?
- Cottonwood Lake in Cottonwood County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 2.1 ft visibility. Phosphorus: 60 µg/L. Chlorophyll-a (algae): 18.2 µg/L. Maximum depth: 10 ft. Surface area: 154.97 acres.
Is Cottonwood Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Cottonwood Lake is listed impaired under Clean Water Act §303(d) (IR 5) for impaired biota (cause unknown). Check local advisories before you swim.
What is the water temperature of Cottonwood Lake?
- Cottonwood Lake typically sits around 73°F at the surface in September, from 20 EPA Water Quality Portal field readings (2022–2025). That is a typical value for the month, not a live reading.
How deep is Cottonwood Lake?
- Cottonwood Lake has a maximum depth of 10 feet and an average depth of 8 feet. The lake covers 154.97 acres.
What fish are in Cottonwood Lake?
- Fish species found in Cottonwood Lake include bigmouth buffalo, black bullhead, black crappie, bluegill, channel catfish, common carp, largemouth bass, northern pike, orangespotted sunfish, pumpkinseed, smallmouth bass, walleye, white sucker, yellow bullhead, yellow perch. Cottonwood Lake is located in Cottonwood County, Minnesota.
What did the DNR fisheries survey find at Cottonwood Lake?
- Minnesota DNR's Standard Survey on August 19, 2024 caught 3.67 walleye per gill net at Cottonwood Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Cottonwood Lake’s water-quality measurements separately, and the water-quality trend over 2 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Cottonwood Lake?
- Cottonwood Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Cottonwood Lake. Public access is listed as yes.
Can I fish at Cottonwood Lake?
- Cottonwood Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Minnesota's fish and wildlife agency, so check its current regulations before you go.
Explore Cottonwood Lake across LakeQuality
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Fish species and best lakes in Cottonwood County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its readings
Minnesota's cleanest lakes, ranked on agency measurements
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State Parks Near Cottonwood Lake
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Where this data comes from
16 measurements from 1 monitoring station, 2022–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA16 samples · 2022–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- 2120 B ~ Color in Water by Visual Comparison
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from 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