Clear Lake
Washington County, Minnesota429 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Clear Lake. Here is what has been measured.
- Eutrophic
- Impaired · Impaired biota (cause unknown)
- 2 aquatic invasives
- 28 ft max depth
- Public access
Clear Lake in Washington County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 6.2 ft visibility. Phosphorus: 33 µg/L. Chlorophyll-a (algae): 6.9 µg/L. Maximum depth: 28 ft. Surface area: 428.95 acres.
Minnesota DNR's Targeted Survey on June 20, 2024 caught 9.00 walleye per gill net at Clear Lake. DNR survey details →
Clear Lake is a 429-acre productive, nutrient-rich eutrophic lake in Washington County, Minnesota with a maximum depth of 28 feet. Water clarity is declining over recent sampling years. The lake supports 14 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing. Compared to the 74 other monitored lakes in Washington County, Clear Lake ranks #26 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-10-10. Methodology: how these readings are compared.
What Clear Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Fishing14 species recorded
- Ice seasonIce-out around Apr 11
Swimming conditions
Readings onlyModerate 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. Clear Lake is listed impaired under Clean Water Act §303(d) (IR 5) for impaired biota (cause unknown), mercury, pFAS. 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.
Murky, only visible to about 6.2 ft. Phosphorus 33 µg/L. Chlorophyll-a 6.9 µg/L. TSI 52.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 6.2ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 33µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | 6.9µg/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. | 52 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced 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 61°F at the surface in October. Summer average is about 69°F. Usually warmest in Aug (about 72°F) and coldest in Feb (about 39°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (39°F) to its warmest (72°F).
Typical surface water temperature by month, from 689 field readings (2010–2024) 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 high (155,597 cells/mL) on May 30, 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 June 20, 2024 caught 9.00 walleye per gill net at Clear Lake.
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 5 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
17 surveys on file from MN DNR Fisheries. Most recent: 2024-06-20 (Targeted Survey).
17 surveys on file · most recent 2024-06-20 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Spottail Shiner | 351.14 | ||
| Bluntnose Minnow | 154.03 | ||
| Bluegill | 26.03 | 3–7 in 2024-06-20 | 0.15 lb |
| Black Bullhead | 24.14 | 7–11 in 2024-06-20 | 0.19 lb |
| Black Crappie | 18.84 | 4–9 in 2024-06-20 | 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
From the 2024-06-20 survey
Clear Lake is a eutrophic, class 24 lake located in northern Washington County. The Lake is 424 acres in surface area, with 267 acres being littoral (63%). The lake's maximum depth is 28 feet. Primary management species are Walleye and Hybrid (Tiger) Muskellunge, and the secondary management species is Northern Pike.…
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
28 ft
Surface area
429 acres
Shoreline
4.3 mi
Littoral zone
62%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
5 sq mi
HydroLAKES / HydroSHEDS
Elevation
876 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 Washington 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 Clear Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
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Fish Species
Click a species to see every lake where it is documented.
Fishing Clear Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
Water Quality Trend: Stable
Based on 5 years of monitoring (2020–2024).
Water clarity
Worsening5 years
Phosphorus
Stable+0.25 µg/L/yr3 years
Chlorophyll-a
Improving-1.6 µg/L/yr3 years
Ice season
Typical ice-out
Apr 11
Earliest Mar 16, 2016 · Latest May 1, 2018
Typical ice-in
Nov 23
Earliest Nov 13, 2018 · Latest Dec 6, 2017
Most recent ice-out
Apr 12
2022
15 observations · Minnesota PCA ice records
EPA Impairment Status
Clear 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, Fish consumption.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN82-0163-00 · 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. 1 facility has a reported Clean Water Act violation in the past three years.
- Saint Croix Forge IncForest Lake · 0.6 mi away · NPDES MN0069051Recent violation
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 Washington County
Frequently asked questions about Clear Lake
Where is Clear Lake?
- Clear Lake is a lake in Washington 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 Washington County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 6.2 ft visibility. Phosphorus: 33 µg/L. Chlorophyll-a (algae): 6.9 µg/L. Maximum depth: 28 ft. Surface area: 428.95 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 5) for impaired biota (cause unknown), mercury, pFAS. Check local advisories before you swim.
What is the water temperature of Clear Lake?
- Clear Lake typically sits around 61°F at the surface in October, from 689 EPA Water Quality Portal field readings (2010–2024). That is a typical value for the month, not a live reading.
How deep is Clear Lake?
- Clear Lake has a maximum depth of 28 feet. The lake covers 428.95 acres.
What fish are in Clear Lake?
- Fish species found in Clear Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), common carp, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, tiger muskellunge, walleye, white sucker, yellow bullhead, yellow perch. Clear Lake is located in Washington County, Minnesota.
What did the DNR fisheries survey find at Clear Lake?
- Minnesota DNR's Targeted Survey on June 20, 2024 caught 9.00 walleye per gill net at Clear Lake. 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 5 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
When does Clear Lake thaw?
- Clear Lake typically has ice-out around Apr 11. Ice typically forms around Nov 23. The open water season is approximately 226 days.
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 high (155,597 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
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Where this data comes from
130 measurements from 2 monitoring stations, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA130 samples · 2020–2024
Analytical methods
- Field measurement/observation, generic method
- 4500 P E ~ Phosphorus in Water by Colorimetry- Ascorbic Acid Method
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (2)
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
Ice data from Minnesota DNR Climate