Pearly Lake-Deep Spot
Cheshire County, New Hampshire210 acresView mapDirections
NHDES publishes the water-quality measurements for Pearly Lake-Deep Spot. Here is what has been measured.
- Eutrophic
- Impaired · Algal growth
Pearly Lake-Deep Spot in Cheshire County, New Hampshire has water-quality measurements published by NHDES, shown here as reported. Phosphorus: 29.7 µg/L. Chlorophyll-a (algae): 8.3 µg/L. Surface area: 210 acres.
Pearly Lake-Deep Spot is a 210-acre productive, nutrient-rich eutrophic lake in Cheshire County, New Hampshire. Compared to the 37 other monitored lakes in Cheshire County, Pearly Lake-Deep Spot ranks #37 for water quality.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2025-09-01. Methodology: how these readings are compared.
Swimming conditions
Readings onlyBacteria advisory
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. Pearly Lake-Deep Spot is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, biotoxins, mercury, nuisance exotic species, oxygen depletion (low DO), pH / acidity. Check local advisories before you swim.
Whether Pearly 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 Pearly Lake-Deep Spot
These are the measurements NHDES publishes for Pearly 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 29.7 µg/L. Chlorophyll-a 8.3 µg/L. TSI 52.
| 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 | 29.7µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 8.3µg/L | Measured, not scored The green pigment in algae — a direct measure of how much algae is in the water. |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 52 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Pearly Lake-Deep Spot
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
210 acres
No bathymetric survey has been published for Pearly Lake-Deep Spot, so its depth is not documented here.
Stays via Stay22
Stays near Pearly Lake-Deep Spot
Compare lakeside cabins, hotels, and vacation rentals near Pearly Lake-Deep Spot 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. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Pearly Lake-Deep Spot are listed below.
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Fishing Pearly Lake-Deep Spot
Reservoir Info (USACE NID)
Pearly Lake-Deep Spot is a man-made reservoir impounded by the Pearly Pond Dam (completed 1935), built primarily for recreation on the Tarbell Brook; concrete-type dam, 7 ft tall and 120 ft long.
- Surface area
- 210 ac
- Normal storage
- 500 ac-ft
- Max storage
- 750 ac-ft
- Drainage area
- 2.8 sq mi
- Hazard class
- Low
- Owner
- PEARLY POND ASSOCIATION
Source: USACE National Inventory of Dams, NID ID NH00383 · Operator website · Matched by proximity (0.3 km)
EPA Impairment Status
Pearly 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, Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit NHLAK802020103-08 · Official waterbody report
Nearby Lakes in Cheshire County
Frequently asked questions about Pearly Lake-Deep Spot
Where is Pearly Lake-Deep Spot?
- Pearly Lake-Deep Spot is a lake in Cheshire County, New Hampshire. Its water-quality measurements are published by NHDES and shown on this page as reported.
What is the water quality of Pearly Lake-Deep Spot?
- Pearly Lake-Deep Spot in Cheshire County, New Hampshire has water-quality measurements published by NHDES, shown here as reported. Phosphorus: 29.7 µg/L. Chlorophyll-a (algae): 8.3 µg/L. Surface area: 210 acres.
Is Pearly Lake-Deep Spot safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Pearly Lake-Deep Spot is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, biotoxins, mercury, nuisance exotic species, oxygen depletion (low DO), pH / acidity. Check local advisories before you swim.
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Where this data comes from
30 measurements from 1 monitoring station, 2021–2025. Retrieved from the EPA Water Quality Portal on 2026-08-21.
Collected and reported by
- New Hampshire Department Of Environmental Services (BEACH)
1111330030 samples · 2021–2025
Analytical methods
- 10-115-01-1 F ~ LACHAT; Total Phosphorus- Manual persulfate digest
- CHLOROPHYLL A-B-C DETERMINATION (MODIFIED)
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