Where is Flat Mountain Ponds?

Flat Mountain Ponds is a lake in Grafton County, New Hampshire. Its water-quality measurements are published by NHDES and shown on this page as reported.

How deep is Flat Mountain Ponds?

Flat Mountain Ponds has a maximum depth of 10 feet. The lake covers 28 acres.

Are there campgrounds on Flat Mountain Ponds?

Flat Mountain Ponds has 1 public campground from USGS The National Map within 5 km, including Flat Mtn Pond Shelter. This is a location join, not a booking. Cabins and hotels are listed separately; campsite reservations use the official link when the source provides one.

Flat Mountain Ponds

Grafton County, New Hampshire28 acresView map Directions

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

Max depth

10 ft

Bathymetric survey

Area

28 acres

Surface area

Shoreline

1.6 mi

Measured length

Impaired · Mercury
10 ft max depth

See the measurements Directions Where to stay

Flat Mountain Ponds in Grafton County, New Hampshire has water-quality measurements published by NHDES, shown here as reported. Maximum depth: 10 ft. Surface area: 28 acres.

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Flat Mountain Ponds is a 28-acre lake in Grafton County, New Hampshire with a maximum depth of 10 feet.

Source: EPA Water Quality Portal sampling records, your state environmental agency. Methodology: how these readings are compared.

What Flat Mountain Ponds is good for

From access and monitoring records, not editorial picks.

Camping1 public campground nearby

Swimming conditions

No reading

Not rated

Nutrient and algae readings are not a swimming clearance. Flat Mountain Ponds is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury, metals (other than mercury), pH / acidity. Check local advisories before you swim.

Whether Flat Mountain Ponds 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.

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Water quality measurements for Flat Mountain Ponds

These are the measurements NHDES publishes for Flat Mountain Ponds, 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 Flat Mountain Ponds

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

Lake Details

Max depth

10 ft

Surface area

28 acres

Shoreline

1.6 mi

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

Recreation & Access

Campgrounds

Public campgrounds near Flat Mountain Ponds

Flat Mtn Pond Shelter0.5 km

Nearest public campgrounds in the USGS National Map inventory, within about 3 miles. An empty list means USGS records no campground that close, which is not the same as camping being unavailable. Where the source gives an official reservation link, it is used; the cabin and hotel search does not cover campsites. More camping lakes

Stays via Stay22

Stays near Flat Mountain Ponds

Compare lakeside cabins, hotels, and vacation rentals near Flat Mountain Ponds in Grafton 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 Flat Mountain Ponds

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Fishing Flat Mountain Ponds

→ Flat Mountain Ponds fishing regulations (limits, seasons, special rules)

EPA Impairment Status

Flat Mountain Ponds is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).

Causes of impairment

MercuryMetals (other than mercury)pH / acidity

Designated uses not supporting: Aquatic life, Fish consumption.

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit NHLAK600020602-02 · Official waterbody report

Nearby Lakes in Grafton County

Church Ponds7.3 miView →Sawyer Pond-Deep Spot—View →Perch Pond—View →Campton Pond—View →White Oak PondMesotrophic—View →Russell Pond—View →

Frequently asked questions about Flat Mountain Ponds

Where is Flat Mountain Ponds?: Flat Mountain Ponds is a lake in Grafton County, New Hampshire. Its water-quality measurements are published by NHDES and shown on this page as reported.
What is the water quality of Flat Mountain Ponds?: Flat Mountain Ponds in Grafton County, New Hampshire has water-quality measurements published by NHDES, shown here as reported. Maximum depth: 10 ft. Surface area: 28 acres.
Is Flat Mountain Ponds safe to swim in?: Nutrient and algae readings are not a swimming clearance. Flat Mountain Ponds is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury, metals (other than mercury), pH / acidity. Check local advisories before you swim.
How deep is Flat Mountain Ponds?: Flat Mountain Ponds has a maximum depth of 10 feet. The lake covers 28 acres.
Are there campgrounds on Flat Mountain Ponds?: Flat Mountain Ponds has 1 public campground from USGS The National Map within 5 km, including Flat Mtn Pond Shelter. This is a location join, not a booking. Cabins and hotels are listed separately; campsite reservations use the official link when the source provides one.