Contoocook Lake Dam
Contoocook Lake Dam in Cheshire County, New Hampshire is not rated for water quality — its monitoring record does not meet the evidence bar. Surface area: 443 acres.
- Area
- 443 acres
Why Contoocook Lake Dam has no grade
We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Contoocook Lake Dam, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by your state environmental agency and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Contoocook Lake Dam is a 443-acre lake in Cheshire County, New Hampshire.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2024-08-23. Grade methodology: LakeGrade methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Contoocook Lake Dam
These readings exist but do not meet the evidence bar for an A–F grade — see why.
No clarity data.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples |
Where to stay near Contoocook Lake Dam
Compare lakeside cabins, hotels, and vacation rentals near Contoocook Lake Dam in Cheshire 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 Contoocook Lake Dam
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Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 443 acres |
No bathymetric survey has been published for Contoocook Lake Dam, so its depth is not documented here.
Fishing Contoocook Lake Dam
Reservoir Info (USACE NID)
Contoocook Lake Dam is a man-made reservoir impounded by the Contoocook Lake Dam (completed 1885), built primarily for recreation on the Contoocook River; earth-type dam, 7 ft tall and 400 ft long.
- Surface area
- 443 ac
- Normal storage
- 1,548 ac-ft
- Max storage
- 2,726 ac-ft
- Drainage area
- 15.6 sq mi
- Hazard class
- Low
- Owner
- TOWN OF JAFFREY
Source: USACE National Inventory of Dams, NID ID NH00098 · Operator website
EPA Impairment Status
Contoocook Lake Dam is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit NHIMP700030101-02 · Official waterbody report · Matched by proximity (1.14 km)
Graded lakes near Contoocook Lake Dam
Contoocook Lake Dam has no grade, but these lakes within a short drive do.
Nearby Lakes in Cheshire County
Frequently asked questions about Contoocook Lake Dam
Where is Contoocook Lake Dam?
- Contoocook Lake Dam is a lake in Cheshire County, New Hampshire. LakeQuality has not rated this lake (UNRATED) — there is not enough recent sampling to assign a letter.
What is the water quality grade for Contoocook Lake Dam?
- Contoocook Lake Dam in Cheshire County, New Hampshire is not rated for water quality — its monitoring record does not meet the evidence bar. Surface area: 443 acres.
Is Contoocook Lake Dam safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Contoocook Lake Dam is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
Explore Contoocook Lake Dam across LakeGrade
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Where this data comes from
9 measurements from 1 monitoring station, 2022–2024. Retrieved from the EPA Water Quality Portal on 2026-08-21.
Collected and reported by
- New Hampshire Department Of Environmental Services (BEACH)
111133009 samples · 2022–2024
Analytical methods
- Turbidity by Nephelometry
Monitoring station identifiers (1)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database