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LakeQuality

Downs Lake

Washington County, MinnesotaView mapDirections

Minnesota PCA publishes the water-quality measurements for Downs Lake. Here is what has been measured.

Clarity
1.8 ft
Murkier than most
Secchi · sampled 2024
Phosphorus
159 µg/L
More phosphorus than most
Measured by Minnesota PCA
Chlorophyll-a
68.5 µg/L
More algae than most
Measured by Minnesota PCA
Water temp
~53°F
Typical for Oct · EPA WQP
Type
Hypereutrophic
Trophic class
Trend
Stable
5 years of samples
  • Hypereutrophic
  • Impaired · Nutrients (phosphorus, nitrogen)
  • Limited data

Downs Lake in Washington County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 1.8 ft visibility. Phosphorus: 159 µg/L. Chlorophyll-a (algae): 68.5 µg/L.

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Downs Lake is a highly nutrient-loaded hypereutrophic lake in Washington County, Minnesota. Limited fish-species data available. No public access — the lake is private or restricted. Compared to the 74 other monitored lakes in Washington County, Downs Lake ranks #75 for water quality.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-10-08. Methodology: how these readings are compared.

Swimming conditions

Readings only

Recreation use not supported

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. Downs Lake is listed impaired under Clean Water Act §303(d) (IR 5) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.

Whether Downs 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.

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Water quality measurements for Downs Lake

These are the measurements Minnesota PCA publishes for Downs Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.

Very murky, less than 1.8 ft of visibility. Phosphorus 159 µg/L. Chlorophyll-a 68.5 µg/L. TSI 73.

Water quality readings
MeasureReadingWhere it sits
Water clarity (Secchi depth)1.8ftMeasured, not scored

How deep a black-and-white disk stays visible from the surface. Higher is clearer.

Total phosphorus159µg/LPoor
GoodFairPoor
Chlorophyll-a (algae)68.5µg/LPoor
GoodFairPoor
Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a.73Hypereutrophic
OligotrophicMesotrophicEutrophicHypereutrophic

Very high nutrients, dense algae, poor clarity

Ask about Downs Lake

Answers come straight from the public measurements and survey records on this page.

Water Temperature

Downs Lake typically sits around 53°F at the surface in October. Summer average is about 73°F. Usually warmest in Jul (about 77°F) and coldest in Oct (about 53°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
63°
May
69°
Jun
77°
Jul
73°
Aug
70°
Sep
53°
Oct
Nov
Dec

Column height runs from this lake’s coldest month (53°F) to its warmest (77°F).

Typical surface water temperature by month, from 14 field readings (2019–2024) via the EPA Water Quality Portal. See the full Downs Lake water temperature breakdown →

Stays via Stay22

Stays near Downs Lake

Compare lakeside cabins, hotels, and vacation rentals near Downs 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 readings cover nutrients and algae, not lodging. Cabins and rentals around Downs Lake are listed below.

Top-rated places to stay near Downs 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.

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Fishing Downs Lake

Based on 5 years of monitoring (2020–2025).

  • Water clarity

    Stable

    5 years

See year-by-year chart →

EPA Impairment Status

Downs Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

Nutrients (phosphorus, nitrogen)

Designated uses not supporting: Recreation.

Source: EPA ATTAINS assessment unit MN82-0110-00 · Official waterbody report

Nearby Lakes in Washington County

Frequently asked questions about Downs Lake

Where is Downs Lake?

Downs 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 Downs Lake?

Downs Lake in Washington County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 1.8 ft visibility. Phosphorus: 159 µg/L. Chlorophyll-a (algae): 68.5 µg/L.

Measurements on this page ↑

Is Downs Lake safe to swim in?

Nutrient and algae readings are not a swimming clearance. Downs Lake is listed impaired under Clean Water Act §303(d) (IR 5) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.

Swimming on this page ↑

What is the water temperature of Downs Lake?

Downs Lake typically sits around 53°F at the surface in October, from 14 EPA Water Quality Portal field readings (2019–2024). That is a typical value for the month, not a live reading.

Temp on this page ↑

Can I fish at Downs Lake?

Public access to Downs Lake is listed as no on the lake record, so confirm before you make the trip. 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.

Hypereutrophic Lakes in Minnesota

Where this data comes from

28 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 WaterMNPCA28 samples · 2024

Analytical methods

  • Field measurement/observation, generic method
  • Phosphorus by Colorimetry
  • Analysis of Chlorophyll in Periphyton and Plankton
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