Loon Lake
Carroll County, New Hampshire189 acresView mapDirections
No nutrient or algae sampling on record from NHDES for this lake.
- Impaired · Mercury
- 50 ft max depth
Loon Lake in Carroll County, New Hampshire has water-quality measurements published by NHDES, shown here as reported. Maximum depth: 50 ft. Surface area: 189 acres.
Loon Lake is a 189-acre lake in Carroll County, New Hampshire with a maximum depth of 50 feet (24-foot average).
Source: EPA Water Quality Portal sampling records, your state environmental agency. Methodology: how these readings are compared.
What Loon Lake is good for
From access and monitoring records, not editorial picks.
- Deep water50 ft surveyed max depth
Swimming conditions
No readingNot rated
Nutrient and algae readings are not a swimming clearance. Loon Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Whether Loon Lake is safe to swim in today is a call for the New Hampshire Department of Environmental Services and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Loon Lake
These are the measurements NHDES publishes for Loon 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 Loon Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
50 ft
Average depth
24 ft
Surface area
189 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 Loon Lake
Compare lakeside cabins, hotels, and vacation rentals near Loon Lake in Carroll County, New Hampshire — 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 Loon 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.
Follow Loon Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fishing Loon Lake
EPA Impairment Status
Loon Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
Designated uses not supporting: Fish consumption.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit NHLAK600020901-01 · Official waterbody report
Nearby Lakes in Carroll County
Frequently asked questions about Loon Lake
Where is Loon Lake?
- Loon Lake is a lake in Carroll County, New Hampshire. Its water-quality measurements are published by NHDES and shown on this page as reported.
What is the water quality of Loon Lake?
- Loon Lake in Carroll County, New Hampshire has water-quality measurements published by NHDES, shown here as reported. Maximum depth: 50 ft. Surface area: 189 acres.
Is Loon Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Loon Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
How deep is Loon Lake?
- Loon Lake has a maximum depth of 50 feet and an average depth of 24 feet. The lake covers 189 acres.
Explore Loon Lake across LakeQuality
More lakes in New Hampshire
Other Lakes in New Hampshire
Where this data comes from
Measurements for Loon Lake come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database