Clear Lake
Clear Lake in Washington County, Minnesota has a water quality grade of A (Excellent). Water clarity: 14 ft visibility. Phosphorus: 16 µg/L. Chlorophyll-a (algae): 3.1 µg/L. Maximum depth: 27 ft. Surface area: 41.72 acres.
- Clarity
- 14 ft
- Typical in August
- 65°F
- Max depth
- 27 ft
- Area
- 42 acres
- Type
- Mesotrophic
- Trend
- → Stable
- Public access
- No
- Ice-out
- Mar 20
Next lake in Washington County
Clear Lake is a 42-acre mesotrophic lake in Washington County, Minnesota with a maximum depth of 27 feet (5-foot average). Water quality is graded A based on 2 sampling years through 2024. Phosphorus level is declining over recent sampling years. The lake supports 6 documented fish species including black crappie, bluegill, and green sunfish. No public access — the lake is private or restricted. Compared to the 74 other monitored lakes in Washington County, Clear Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-10-17. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLimited data
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.
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A (Excellent)
Good clarity, visible to about 14 ft. Phosphorus level: 16 µg/L. Chlorophyll-a: 3.1 µg/L. Trophic State Index: 42.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 14 ft | Not graded |
| Phosphorus | 16 µg/L | Good |
| Chlorophyll-a (Algae) | 3.1 µg/L | Good |
| Trophic State Index (TSI) | 42 | Mesotrophic |
Moderate nutrients, good water quality
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.
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Water Temperature
Clear Lake typically sits around 65°F at the surface in August. Summer average is about 62°F. Usually warmest in Aug (about 65°F) and coldest in Apr (about 46°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 170 field readings (2010–2024) via the EPA Water Quality Portal.
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 27 ft |
| Average Depth | 5 ft |
| Surface Area | 42 acres |
| Shoreline Length | 1.3 mi |
| Littoral Zone | 70% |
| Public Access | No |
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Clear Lake
Water Quality Trend: → Stable
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | +0.048 m/yr | 6 |
| Phosphorus | ↓ Declining | +1.75 µg/L/yr | 2 |
| Chlorophyll-a | ↑ Improving | -0.3 µg/L/yr | 2 |
Ice Season
Historical ice data from Minnesota DNR (5 observations).
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2012-03-19 (2012) | 2009-04-04 (2009) |
| Ice-In | 2012-11-23 (2012) | 2009-12-08 (2009) |
Most recent ice-out: 2012-03-19
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
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN82-0046-00 · Official waterbody report · Matched by proximity (1.77 km)
County Ranking
Ranked #2 of 75 lakes in Washington County
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 A (Excellent). Water clarity: 14 ft visibility. Phosphorus: 16 µg/L. Chlorophyll-a (algae): 3.1 µg/L. Maximum depth: 27 ft. Surface area: 41.72 acres.
Is Clear Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Clear Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 3.1 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Clear Lake?
- Clear Lake typically sits around 65°F at the surface in August, from 170 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 27 feet and an average depth of 5 feet. The lake covers 41.72 acres.
What fish are in Clear Lake?
- Fish species found in Clear Lake include black crappie, bluegill, green sunfish, hybrid sunfish, largemouth bass, northern pike. Clear Lake is located in Washington County, Minnesota.
When does Clear Lake thaw?
- Clear Lake typically has ice-out around Mar 20.
Explore Clear Lake across LakeGrade
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Moderate nutrients, good water quality
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Other Grade A Lakes in Minnesota
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Where this data comes from
48 measurements from 1 monitoring station, 2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA48 samples · 2024
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- Analysis of Chlorophyll in Periphyton and Plankton
Monitoring station identifiers (1)
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Ice data from Minnesota DNR Climate