Clear Lake
Clear Lake in Washington County, Minnesota has a water quality grade of C (Fair). 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.
- Clarity
- 6.2 ft
- Typical in August
- 72°F
- Max depth
- 28 ft
- Area
- 429 acres
- Type
- Eutrophic
- Trend
- → Stable
- Public access
- Yes
- Ice-out
- Apr 11
- Open water
- 226 days
Next lake in Washington County
Clear Lake is a 429-acre productive, nutrient-rich eutrophic lake in Washington County, Minnesota with a maximum depth of 28 feet. Water quality is graded C based on 2 sampling years through 2024. 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 2 public boat landings. 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. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyModerate
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.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
Murky, only visible to about 6.2 ft. Phosphorus level: 33 µg/L. Chlorophyll-a: 6.9 µg/L. Trophic State Index: 52.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 6.2 ft | Not graded |
| Phosphorus | 33 µg/L | Fair |
| Chlorophyll-a (Algae) | 6.9 µg/L | Good |
| Trophic State Index (TSI) | 52 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay 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
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Planning a whole trip? See where to stay at Minnesota’s top lakes →
Water Temperature
Clear Lake typically sits around 72°F at the surface in August. 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.
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 ↗
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 28 ft |
| Surface Area | 429 acres |
| Shoreline Length | 4.3 mi |
| Littoral Zone | 62% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Forest Lake #1 - Lakeside ParkPublic
- Clear LakePublic
Fish Species
Click a species to see every graded 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.
DNR Fisheries Survey Summary
17 surveys on file from MN DNR Fisheries. Most recent: 2024-06-20 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Spottail Shiner | 351.14 | — |
| Bluntnose Minnow | 154.03 | — |
| JND | 31.91 | — |
| Bluegill | 26.03 | 0.15 lb |
| Black Bullhead | 24.14 | 0.19 lb |
| Black Crappie | 18.84 | 0.17 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.
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
Water Quality Trend: → Stable
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.056 m/yr | 5 |
| Phosphorus | → Stable | +0.25 µg/L/yr | 3 |
| Chlorophyll-a | ↑ Improving | -1.6 µg/L/yr | 3 |
Ice Season
Historical ice data from Minnesota DNR (15 observations).
Estimated open water season: 226 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2016-03-16 (2016) | 2018-05-01 (2018) |
| Ice-In | 2018-11-13 (2018) | 2017-12-06 (2017) |
Most recent ice-out: 2022-04-12
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
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.
County Ranking
Ranked #26 of 75 lakes in Washington County
Nearby Lakes With Higher Grades
Clear Lake holds Grade C. One nearby lake has a higher nutrient-and-algae grade — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Washington County
Frequently asked questions about Clear Lake
What is the water quality grade for Clear Lake?
- Clear Lake in Washington County, Minnesota has a water quality grade of C (Fair). 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?
- Generally safe for swimming, moderate water quality. Clear Lake has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 6.9 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Clear Lake?
- Clear Lake typically sits around 72°F at the surface in August, 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.
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 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Forest Lake #1 - Lakeside Park, Clear Lake. Public access is listed as yes.
Explore Clear Lake across LakeGrade
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High nutrients, frequent algae, reduced clarity
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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)
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
Ice data from Minnesota DNR Climate