Long Lake is a lake in Washington County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.

How deep is Long Lake?

Long Lake has a maximum depth of 22 feet. The lake covers 94 acres.

Long Lake

Washington County, Minnesota94 acresView map Directions

No nutrient or algae sampling on record from Minnesota PCA for this lake.

Max depth

22 ft

Bathymetric survey

Area

94 acres

Surface area

Shoreline

3.3 mi

Measured length

Impaired · Nutrients (phosphorus, nitrogen)
22 ft max depth

See the measurements Directions Where to stay

Long Lake in Washington County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Maximum depth: 22 ft. Surface area: 94 acres.

Loading map…

Long Lake is a 94-acre lake in Washington County, Minnesota with a maximum depth of 22 feet.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder. Methodology: how these readings are compared.

Swimming conditions

No reading

Recreation use not supported

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

Whether Long 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.

Compare swimming lakes near St. Paul →

Get alerts for Long Lake →

Water quality measurements for Long Lake

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

No clarity data. TSI undefined.

Ask about Long Lake

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

Lake Details

Max depth

22 ft

Surface area

94 acres

Shoreline

3.3 mi

The depth above comes from a bathymetric survey of this lake, not from a regional estimate.

Stays via Stay22

Stays near Long Lake

Compare lakeside cabins, hotels, and vacation rentals near Long 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 Long Lake

Prices for Oct 16–18, 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.

Planning a whole trip? See where to stay at Minnesota’s top lakes →

Follow Long Lake’s readings

Email me when new measurements post for this lake. Updates stay free.

Or email

Fishing Long Lake

→ Long Lake fishing regulations (limits, seasons, special rules)

EPA Impairment Status

Long 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)Salinity / chlorides

Designated uses not supporting: Aquatic life, Recreation.

Source: EPA ATTAINS assessment unit MN82-0021-00 · Official waterbody report

Nearby Lakes in Washington County

Cloverdale Lake5 ft clear · Eutrophic1.9 miView →Lily Lake10.5 ft clear · Mesotrophic1.4 miView →Mckusick Lake6 ft clear · Eutrophic1.6 miView →McDonald Lake2.1 miView →South Twin Lake5 ft clear · Eutrophic2.2 miView →Mcdonald Lake5 ft clear · Eutrophic2.3 miView →

Frequently asked questions about Long Lake

Where is Long Lake?: Long 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 Long Lake?: Long Lake in Washington County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Maximum depth: 22 ft. Surface area: 94 acres.
Is Long Lake safe to swim in?: Nutrient and algae readings are not a swimming clearance. Long Lake is listed impaired under Clean Water Act §303(d) (IR 5) for nutrients (phosphorus, nitrogen), salinity / chlorides. Check local advisories before you swim.
How deep is Long Lake?: Long Lake has a maximum depth of 22 feet. The lake covers 94 acres.