Contoocook Lake-South End
Contoocook Lake-South End in Cheshire County, New Hampshire is not rated for water quality — its monitoring record does not meet the evidence bar. Phosphorus: 11.5 µg/L.
- Public access
- Yes
Why Contoocook Lake-South End 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-South End, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). Sampling here has recorded phosphorus, but not water clarity and algae (chlorophyll-a).
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-South End is a lake in Cheshire County, New Hampshire. Limited fish-species data available. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2025-07-10. 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-South End
These readings exist but do not meet the evidence bar for an A–F grade — see why.
No clarity data. Phosphorus level: 11.5 µg/L. Trophic State Index: 39.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | 11.5 µg/L | Not graded |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 39 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Contoocook Lake-South End
Compare lakeside cabins, hotels, and vacation rentals near Contoocook Lake-South End 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-South End
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Recreation & Access
- Contoocook LakePublic
Named access points from the USGS National Boat Ramps inventory, snapped within 5 km. More lakes with boat ramps
Fishing Contoocook Lake-South End
EPA Impairment Status
Contoocook Lake-South End 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 NHIMP700030101-10 · Official waterbody report · Matched by proximity (0.8 km)
Graded lakes near Contoocook Lake-South End
Contoocook Lake-South End has no grade, but these lakes within a short drive do.
Nearby Lakes in Cheshire County
Frequently asked questions about Contoocook Lake-South End
Where is Contoocook Lake-South End?
- Contoocook Lake-South End 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-South End?
- Contoocook Lake-South End in Cheshire County, New Hampshire is not rated for water quality — its monitoring record does not meet the evidence bar. Phosphorus: 11.5 µg/L.
Is Contoocook Lake-South End safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Contoocook Lake-South End is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
Are there boat ramps on Contoocook Lake-South End?
- Contoocook Lake-South End has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Contoocook Lake. Public access is listed as yes.
Explore Contoocook Lake-South End 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 Lakes in New Hampshire
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Hillsborough County · Not rated
Sullivan County · Not rated
Merrimack County · Not rated
Oligotrophic Lakes in New Hampshire
Where this data comes from
3 measurements from 1 monitoring station, 2025. Retrieved from the EPA Water Quality Portal on 2026-08-21.
Collected and reported by
- New Hampshire Department Of Environmental Services (BEACH)
111133003 samples · 2025
Analytical methods
- 10-115-01-1 F ~ LACHAT; Total Phosphorus- Manual persulfate digest
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
Named boat-access points from the USGS National Boat Ramps inventory