Stinson Lake-Deep Spot
Grafton County, New HampshireView mapDirections
NHDES publishes the water-quality measurements for Stinson Lake-Deep Spot. Here is what has been measured.
- Oligotrophic
- Impaired · Mercury
Stinson Lake-Deep Spot in Grafton County, New Hampshire has water-quality measurements published by NHDES, shown here as reported. Phosphorus: 5.2 µg/L. Chlorophyll-a (algae): 1.6 µg/L.
Stinson Lake-Deep Spot is a cold, clear oligotrophic lake in Grafton County, New Hampshire. Compared to the 26 other monitored lakes in Grafton County, Stinson Lake-Deep Spot ranks #4 for water quality.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2025-08-20. Methodology: how these readings are compared.
What Stinson Lake-Deep Spot is good for
From access and monitoring records, not editorial picks.
- Camping1 public campground nearby
Swimming conditions
Readings onlyLow algae
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Stinson Lake-Deep Spot is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, metals (other than mercury), pH / acidity. Check local advisories before you swim.
Whether Stinson Lake-Deep Spot 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 Stinson Lake-Deep Spot
These are the measurements NHDES publishes for Stinson Lake-Deep Spot, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
No clarity data. Phosphorus 5.2 µg/L. Chlorophyll-a 1.6 µg/L. TSI 31.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | No reading How deep a black-and-white disk stays visible from the surface. Higher is clearer. | |
| Total phosphorus | 5.2µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 1.6µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 31 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Stinson Lake-Deep Spot
Answers come straight from the public measurements and survey records on this page.
Recreation & Access
Public campgrounds near Stinson Lake-Deep Spot
- Three Ponds Shelter4.2 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 Stinson Lake-Deep Spot
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Top-rated places to stay near Stinson Lake-Deep Spot
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Fishing Stinson Lake-Deep Spot
EPA Impairment Status
Stinson Lake-Deep Spot 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 NHLAK700010306-01 · Official waterbody report
Nearby Lakes in Grafton County
Frequently asked questions about Stinson Lake-Deep Spot
Where is Stinson Lake-Deep Spot?
- Stinson Lake-Deep Spot 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 Stinson Lake-Deep Spot?
- Stinson Lake-Deep Spot in Grafton County, New Hampshire has water-quality measurements published by NHDES, shown here as reported. Phosphorus: 5.2 µg/L. Chlorophyll-a (algae): 1.6 µg/L.
Is Stinson Lake-Deep Spot safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Stinson Lake-Deep Spot is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, metals (other than mercury), pH / acidity. Check local advisories before you swim.
Are there campgrounds on Stinson Lake-Deep Spot?
- Stinson Lake-Deep Spot has 1 public campground from USGS The National Map within 5 km, including Three Ponds 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.
Explore Stinson Lake-Deep Spot across LakeQuality
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Where this data comes from
47 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)
1111330047 samples · 2020–2025
Analytical methods
- 10-115-01-1 F ~ LACHAT; Total Phosphorus- Manual persulfate digest
- CHLOROPHYLL A-B-C DETERMINATION (MODIFIED)
- 2130 B ~ Nephelometric Method
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Public campgrounds from USGS The National Map Structures, within about 3 miles