Fish Lake
Fish Lake in Washington County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 6 ft visibility. Phosphorus: 42 µg/L. Chlorophyll-a (algae): 12 µg/L. Maximum depth: 34 ft. Surface area: 20.7 acres.
- Clarity
- 6 ft
- Typical in August
- 65°F
- Max depth
- 34 ft
- Area
- 21 acres
- Type
- Eutrophic
- Public access
- No
Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Fish Lake →
Next lake in Washington County
Fish Lake is a 21-acre productive, nutrient-rich eutrophic lake in Washington County, Minnesota with a maximum depth of 34 feet. Water quality is graded D based on 2 sampling years through 2024. Limited fish-species data available. No public access — the lake is private or restricted. Compared to the 74 other monitored lakes in Washington County, Fish Lake ranks #50 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-10-21. 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.
Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum
Water Quality Grade: D (Nutrient-rich)
Murky, only visible to about 6 ft. Phosphorus level: 42 µg/L. Chlorophyll-a: 12 µg/L. Trophic State Index: 55.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 6 ft | Not graded |
| Phosphorus | 42 µg/L | Poor |
| Chlorophyll-a (Algae) | 12 µg/L | Fair |
| Trophic State Index (TSI) | 55 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Fish Lake
Compare lakeside cabins, hotels, and vacation rentals near Fish 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Fish Lake are listed below.
Top-rated places to stay near Fish Lake
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Planning a whole trip? See where to stay at Minnesota’s top lakes →
Water Temperature
Fish 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 May (about 49°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 149 field readings (2011–2024) via the EPA Water Quality Portal. See the full Fish Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 34 ft |
| Surface Area | 21 acres |
| Shoreline Length | 0.8 mi |
| Littoral Zone | 68% |
| Public Access | No |
Fishing Fish Lake
EPA Impairment Status
Fish Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit MN82-0137-00 · Official waterbody report
County Ranking
Ranked #50 of 75 lakes in Washington County
Nearby Lakes With Higher Grades
Fish Lake holds Grade D. 2 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
Nearby Lakes in Washington County
Frequently asked questions about Fish Lake
What is the water quality grade for Fish Lake?
- Fish Lake in Washington County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 6 ft visibility. Phosphorus: 42 µg/L. Chlorophyll-a (algae): 12 µg/L. Maximum depth: 34 ft. Surface area: 20.7 acres.
Is Fish Lake safe to swim in?
- Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum. Fish Lake has a water quality grade of D (Nutrient-rich). Algae concentration (chlorophyll-a) is 12 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Fish Lake?
- Fish Lake typically sits around 65°F at the surface in August, from 149 EPA Water Quality Portal field readings (2011–2024). That is a typical value for the month, not a live reading.
How deep is Fish Lake?
- Fish Lake has a maximum depth of 34 feet. The lake covers 20.7 acres.
Explore Fish Lake across LakeGrade
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Fish species and best lakes in Washington County
Species activity outlook by water temperature and season
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High nutrients, frequent algae, reduced clarity
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Where this data comes from
56 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
MNPCA56 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 details from Minnesota DNR LakeFinder