Umbagog Lake
Coos County, New Hampshire7,642 acresView mapDirections
No nutrient or algae sampling on record from NHDES for this lake.
- Impaired · Mercury
- 40 ft max depth
Umbagog Lake in Coos County, New Hampshire has water-quality measurements published by NHDES, shown here as reported. Maximum depth: 40 ft. Surface area: 7642 acres.
Umbagog Lake is a 7,642-acre lake in Coos County, New Hampshire with a maximum depth of 40 feet (13-foot average).
Source: EPA Water Quality Portal sampling records, your state environmental agency. Methodology: how these readings are compared.
What Umbagog Lake is good for
From access and monitoring records, not editorial picks.
- Deep water40 ft surveyed max depth
- Big water7,642 acres
Swimming conditions
No readingNot rated
Nutrient and algae readings are not a swimming clearance. Umbagog Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, pH / acidity. Check local advisories before you swim.
Whether Umbagog 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 Umbagog Lake
These are the measurements NHDES publishes for Umbagog 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 Umbagog Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
40 ft
Average depth
12.5 ft
Surface area
7,642 acres
Shoreline
51.8 mi
The depth above comes from a bathymetric survey of this lake, not from a regional estimate.
Stays via Stay22
Stays near Umbagog Lake
Compare lakeside cabins, hotels, and vacation rentals near Umbagog Lake in Coos 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 Umbagog 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 Umbagog Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fishing Umbagog Lake
EPA Impairment Status
Umbagog Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Aquatic life, Fish consumption.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit NHLAK400010602-04 · Official waterbody report
Nearby Lakes in Coos County
Frequently asked questions about Umbagog Lake
Where is Umbagog Lake?
- Umbagog Lake is a lake in Coos County, New Hampshire. Its water-quality measurements are published by NHDES and shown on this page as reported.
What is the water quality of Umbagog Lake?
- Umbagog Lake in Coos County, New Hampshire has water-quality measurements published by NHDES, shown here as reported. Maximum depth: 40 ft. Surface area: 7642 acres.
Is Umbagog Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Umbagog Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, pH / acidity. Check local advisories before you swim.
How deep is Umbagog Lake?
- Umbagog Lake has a maximum depth of 40 feet and an average depth of 12.5 feet. The lake covers 7642 acres.
Explore Umbagog Lake across LakeQuality
More lakes in New Hampshire
Other Lakes in New Hampshire
Where this data comes from
Measurements for Umbagog 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