Clear Lake
Brown County, Minnesota252 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Clear Lake. Here is what has been measured.
- Hypereutrophic
- Impaired · Nutrients (phosphorus, nitrogen)
- 8 ft max depth
- Public access
Clear Lake in Brown County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 0.8 ft visibility. Phosphorus: 196 µg/L. Chlorophyll-a (algae): 92.8 µg/L. Maximum depth: 8 ft. Surface area: 251.78 acres.
Minnesota DNR's Targeted Survey on April 15, 2019 caught 3.00 walleye per trap net at Clear Lake. Length samples in the latest survey that recorded them ran 15–27 inches. DNR survey details →
Clear Lake is a 252-acre highly nutrient-loaded hypereutrophic lake in Brown County, Minnesota with a maximum depth of 8 feet (5-foot average). Water clarity 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 3 other monitored lakes in Brown County, Clear Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2023-10-11. Methodology: how these readings are compared.
Clear Lake covers about 250 acres in Brown County. It has one public boat landing. If you are planning to stay, you can search lake houses and cabins around Clear Lake on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
What Clear Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Fishing12 species recorded
Swimming conditions
Readings onlyRecreation use not supported
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. Clear Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Clear 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 Clear Lake
These are the measurements Minnesota PCA publishes for Clear 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 0.8 ft of visibility. Phosphorus 196 µg/L. Chlorophyll-a 92.8 µg/L. TSI 78.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 0.8ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 196µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 92.8µg/L | Poor GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 78 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Clear Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Clear Lake typically sits around 50°F at the surface in October. Summer average is about 77°F. Usually warmest in Jun (about 78°F) and coldest in Oct (about 50°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (50°F) to its warmest (78°F).
Typical surface water temperature by month, from 101 field readings (2010–2023) via the EPA Water Quality Portal. See the full Clear Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Clear Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was very high (1,342,765 cells/mL) on July 18, 2026.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Minnesota DNR's Targeted Survey on April 15, 2019 caught 3.00 walleye per trap net at Clear Lake. Length samples in the latest survey that recorded them ran 15–27 inches.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Clear Lake’s water-quality measurements separately, and the water-quality trend over 4 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
13 surveys on file from MN DNR Fisheries. Most recent: 2025-03-17 (Targeted Survey).
13 surveys on file · most recent 2025-03-17 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluegill | 111.75 | 4–6 in 2025-03-17 | 0.18 lb |
| Black Bullhead | 94.63 | 3–11 in 2025-03-17 | 0.33 lb |
| Black Crappie | 59.09 | 3–13 in 2025-03-17 | 0.3 lb |
| Walleye | 24.63 | 15–27 in 2021-03-22 | 1.02 lb |
| Common Carp | 16.75 | 4–17 in 2025-03-17 | 2.64 lb |
| Yellow Perch | 12.66 | 4–11 in 2025-03-17 | 0.17 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.
Bluegill
Black Bullhead
Black Crappie
Walleye
From the 2025-03-17 survey
Clear is a small lake (251 acres) located south of New Ulm, in Brown County. A medium-sized county owned access, with a single cement boat ramp, is present on the southeast shore. A fishing pier is available at the Lost Dog and Fox Hunters County Park. Clear has three miles of shoreline and a maximum depth of eight…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Clear Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — ClearFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — ClearFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — ClearPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
8 ft
Average depth
5 ft
Surface area
252 acres
Shoreline
3 mi
Littoral zone
100%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
3 sq mi
HydroLAKES / HydroSHEDS
Elevation
958 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Clear 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 Clear Lake
Compare lakeside cabins, hotels, and vacation rentals near Clear Lake in Brown 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 Clear Lake are listed below.
Top-rated places to stay near Clear 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 Clear Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Clear Lake
Water Quality Trend: Stable
Based on 4 years of monitoring (2020–2023).
Water clarity
Improving4 years
Phosphorus
Worsening+12.2 µg/L/yr4 years
Chlorophyll-a
Stable-1.25 µg/L/yr4 years
EPA Impairment Status
Clear Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
Designated uses not supporting: Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN08-0011-00 · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Clear Lake under Clean Water Act (NPDES) discharge permits.
- August Schell Brewing CoNew Ulm · 4.5 mi away · NPDES MN0022284
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 Brown County
Frequently asked questions about Clear Lake
Where is Clear Lake?
- Clear Lake is a lake in Brown County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Clear Lake?
- Clear Lake in Brown County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 0.8 ft visibility. Phosphorus: 196 µg/L. Chlorophyll-a (algae): 92.8 µg/L. Maximum depth: 8 ft. Surface area: 251.78 acres.
Is Clear Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Clear Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
What is the water temperature of Clear Lake?
- Clear Lake typically sits around 50°F at the surface in October, from 101 EPA Water Quality Portal field readings (2010–2023). That is a typical value for the month, not a live reading.
How deep is Clear Lake?
- Clear Lake has a maximum depth of 8 feet and an average depth of 5 feet. The lake covers 251.78 acres.
What fish are in Clear Lake?
- Fish species found in Clear Lake include black bullhead, black crappie, bluegill, common carp, green sunfish, hybrid sunfish, largemouth bass, northern pike, walleye, white sucker, yellow bullhead, yellow perch. Clear Lake is located in Brown County, Minnesota.
What did the DNR fisheries survey find at Clear Lake?
- Minnesota DNR's Targeted Survey on April 15, 2019 caught 3.00 walleye per trap net at Clear Lake. Length samples in the latest survey that recorded them ran 15–27 inches. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Clear Lake’s water-quality measurements separately, and the water-quality trend over 4 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
Does Clear Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Clear Lake (clouds, ice, or an off-season gap). The most recent reading was very high (1,342,765 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Are there boat ramps on Clear Lake?
- Clear Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Clear Lake. Public access is listed as yes.
Can I fish at Clear Lake?
- Clear 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 Clear Lake across LakeQuality
Fish species and the cleanest lakes across Minnesota
Fish species and best lakes in Brown County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its readings
Lakes in the Minnesota River Watershed, ranked by water quality
Minnesota's cleanest lakes, ranked on agency measurements
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State Parks Near Clear Lake
Other Lakes in Minnesota
Hypereutrophic Lakes in Minnesota
Where this data comes from
200 measurements from 1 monitoring station, 2020–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA200 samples · 2020–2023
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- Turbidity, Nephelometric Method
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