Powwow River Lake
Powwow River Lake in Rockingham County, New Hampshire has a water quality grade of C (Fair). Phosphorus: 18 µg/L. Chlorophyll-a (algae): 3.9 µg/L. Surface area: 353 acres.
- Area
- 353 acres
- Type
- Mesotrophic
Powwow River Lake is a 353-acre mesotrophic lake in Rockingham County, New Hampshire. Water quality is graded C based on 2 sampling years through 2025. Compared to the 50 other monitored lakes in Rockingham County, Powwow River Lake ranks #23 for water quality.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2025-08-20. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyModerate
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
No clarity data. Phosphorus level: 18 µg/L. Chlorophyll-a: 3.9 µg/L. Trophic State Index: 45.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | 18 µg/L | Fair |
| Chlorophyll-a (Algae) | 3.9 µg/L | Good |
| Trophic State Index (TSI) | 45 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Powwow River Lake
Compare lakeside cabins, hotels, and vacation rentals near Powwow River Lake in Rockingham 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 Powwow River Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 353 acres |
No bathymetric survey has been published for Powwow River Lake, so its depth is not documented here.
Fishing Powwow River Lake
Reservoir Info (USACE NID)
Powwow River Lake is a man-made reservoir impounded by the Powwow Pond Dam (completed 1935), built primarily for recreation on the Powwow River; earth-type dam, 12 ft tall and 250 ft long.
- Surface area
- 353 ac
- Normal storage
- 1,472 ac-ft
- Max storage
- 3,761 ac-ft
- Drainage area
- 29.36 sq mi
- Hazard class
- Significant
- Owner
- NH DES WATER DIVISION
Source: USACE National Inventory of Dams, NID ID NH00440 · Operator website · Matched by proximity (0.28 km)
EPA Impairment Status
Powwow River Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit NHIMP700061403-04-02 · Official waterbody report · Matched by proximity (0.09 km)
County Ranking
Ranked #23 of 51 lakes in Rockingham County
Nearby Lakes in Rockingham County
Frequently asked questions about Powwow River Lake
Where is Powwow River Lake?
- Powwow River Lake is a lake in Rockingham County, New Hampshire. LakeQuality grades it C for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Powwow River Lake?
- Powwow River Lake in Rockingham County, New Hampshire has a water quality grade of C (Fair). Phosphorus: 18 µg/L. Chlorophyll-a (algae): 3.9 µg/L. Surface area: 353 acres.
Is Powwow River Lake safe to swim in?
- Generally safe for swimming, moderate water quality. Powwow River Lake has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 3.9 µg/L. Always check local health department advisories before swimming.
Explore Powwow River Lake across LakeGrade
More New Hampshire Lake Rankings
Top 25 by overall water quality score
Top 25 by Secchi water clarity
Grade A/B + low algae filter
Panfish-rich, public access
Full state directory
Other Grade C Lakes in New Hampshire
Mesotrophic Lakes in New Hampshire
Where this data comes from
27 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-21.
Collected and reported by
- New Hampshire Department Of Environmental Services (BEACH)
1111330027 samples · 2020–2025
Analytical methods
- 10-115-01-1 F ~ LACHAT; Total Phosphorus- Manual persulfate digest
- CHLOROPHYLL A-B-C DETERMINATION (MODIFIED)
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