Clearwater Lake
Clearwater County, Minnesota999 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Clearwater Lake. Here is what has been measured.
- Mesotrophic
- Impaired · Mercury
- 65 ft max depth
- Public access
Clearwater Lake in Clearwater County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 10 ft visibility. Phosphorus: 16 µg/L. Chlorophyll-a (algae): 3.2 µg/L. Maximum depth: 65 ft. Surface area: 998.8 acres.
Minnesota DNR's Targeted Survey on August 14, 2023 caught 12.29 largemouth bass per hour of electrofishing at Clearwater Lake. DNR survey details →
Free interactive depth-contour map of Clearwater Lake, reaching a maximum surveyed depth of 60 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.
Clearwater Lake is a 999-acre mesotrophic lake in Clearwater County, Minnesota with a maximum depth of 65 feet. Overall water quality is declining over recent sampling years. The lake supports 14 documented fish species including black crappie, bluegill, and largemouth bass. Public access is available with 1 public boat landing. Compared to the 36 other monitored lakes in Clearwater County, Clearwater Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-08. Methodology: how these readings are compared.
What Clearwater Lake is good for
From access and monitoring records, not editorial picks.
- Clear water10 ft of visibility
- Boat launch1 documented ramp
- Fishing14 species recorded
- Ice seasonIce-out around Apr 22
- Deep water65 ft surveyed max depth
Swimming conditions
Readings onlyLow algae
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. Clearwater Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Whether Clearwater 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 Clearwater Lake
These are the measurements Minnesota PCA publishes for Clearwater Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 10 ft. Phosphorus 16 µg/L. Chlorophyll-a 3.2 µg/L. TSI 43.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 10ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 16µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 3.2µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 43 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Clearwater Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Clearwater Lake typically sits around 60°F at the surface in September. Summer average is about 66°F. Usually warmest in Jul (about 72°F) and coldest in May (about 53°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (53°F) to its warmest (72°F).
Typical surface water temperature by month, from 85 field readings (2010–2025) via the EPA Water Quality Portal. See the full Clearwater Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Clearwater Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was high (111,686 cells/mL) on December 6, 2025.
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 August 14, 2023 caught 12.29 largemouth bass per hour of electrofishing at Clearwater Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Clearwater Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
12 surveys on file from MN DNR Fisheries. Most recent: 2025-08-12 (Targeted Survey).
12 surveys on file · most recent 2025-08-12 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Yellow Perch | 19.98 | 4–9 in 2023-07-31 | 0.13 lb |
| Bluegill | 9.53 | 3–9 in 2023-07-31 | 0.2 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.
Yellow Perch
Bluegill
From the 2025-08-12 survey
Minnesota DNR Fisheries IBI program staff conducted an assessment of lakeshore habitat on Clearwater Lake on August 12th, 2025, following the Score the Shore survey protocols. The assessment consisted of 71 survey sites evenly spaced 200 meters around the lake. Assessments were made in three habitat zones: Shoreline…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Clearwater Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — ClearwaterFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Clearwater (1712)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — ClearwaterFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — ClearwaterPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
65 ft
Surface area
999 acres
Shoreline
8.6 mi
Littoral zone
34%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
160 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,263 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Clearwater 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 Clearwater Lake
Compare lakeside cabins, hotels, and vacation rentals near Clearwater Lake in Clearwater 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.
Top-rated places to stay near Clearwater 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 Clearwater Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fish Species
Click a species to see every lake where it is documented.
Fishing Clearwater Lake
Water Quality Trend: Worsening
Based on 6 years of monitoring (2020–2025).
Water clarity
Worsening6 years
Phosphorus
Worsening+0.74 µg/L/yr6 years
Chlorophyll-a
Worsening+0.35 µg/L/yr6 years
Ice season
Typical ice-out
Apr 22
Earliest Apr 12, 2024 · Latest May 7, 2022
Typical ice-in
Dec 2
Earliest Nov 13, 2019 · Latest Dec 11, 2001
Most recent ice-out
Apr 12
2024
18 observations · Minnesota PCA ice records
Reservoir Info (USACE NID)
Clearwater Lake is a man-made reservoir impounded by the Clearwater (completed 1931), built primarily for other on the Clearwater River; gravity-type dam, 21 ft tall and 60 ft long.
- Surface area
- 886 ac
- Normal storage
- 31,170 ac-ft
- Max storage
- 38,963 ac-ft
- Drainage area
- 171 sq mi
- Hazard class
- Low
- Owner
- MNDNR-Fisheries
Source: USACE National Inventory of Dams, NID ID MN00232 · Operator website
EPA Impairment Status
Clearwater 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: Fish consumption.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN04-0343-00 · Official waterbody report
Nearby Lakes in Clearwater County
Frequently asked questions about Clearwater Lake
Where is Clearwater Lake?
- Clearwater Lake is a lake in Clearwater County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Clearwater Lake?
- Clearwater Lake in Clearwater County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 10 ft visibility. Phosphorus: 16 µg/L. Chlorophyll-a (algae): 3.2 µg/L. Maximum depth: 65 ft. Surface area: 998.8 acres.
Is Clearwater Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Clearwater Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
What is the water temperature of Clearwater Lake?
- Clearwater Lake typically sits around 60°F at the surface in September, from 85 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
How deep is Clearwater Lake?
- Clearwater Lake has a maximum depth of 65 feet. The lake covers 998.8 acres.
What fish are in Clearwater Lake?
- Fish species found in Clearwater Lake include black crappie, bluegill, largemouth bass, northern pike, pumpkinseed, redhorse, rock bass, shorthead redhorse, silver redhorse, tullibee (cisco), walleye, white sucker, yellow bullhead, yellow perch. Clearwater Lake is located in Clearwater County, Minnesota.
What did the DNR fisheries survey find at Clearwater Lake?
- Minnesota DNR's Targeted Survey on August 14, 2023 caught 12.29 largemouth bass per hour of electrofishing at Clearwater Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Clearwater Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
When does Clearwater Lake thaw?
- Clearwater Lake typically has ice-out around Apr 22. Ice typically forms around Dec 2. The open water season is approximately 224 days.
Does Clearwater Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Clearwater Lake (clouds, ice, or an off-season gap). The most recent reading was high (111,686 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Are there boat ramps on Clearwater Lake?
- Clearwater Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Clearwater Lake. Public access is listed as yes.
Can I fish at Clearwater Lake?
- Clearwater 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 Clearwater Lake across LakeQuality
Fish species and the cleanest lakes across Minnesota
Fish species and best lakes in Clearwater County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its readings
Lakes in the Mississippi Headwaters, ranked by water quality
Minnesota's cleanest lakes, ranked on agency measurements
More lakes in Minnesota
State Parks Near Clearwater Lake
Other Lakes in Minnesota
Mesotrophic Lakes in Minnesota
Compare Clearwater Lake With Nearby Lakes
Where this data comes from
86 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA86 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 (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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory
Ice data from Minnesota DNR Climate