Harantis Lake-Deep Spot
Rockingham County, New Hampshire15 acresView mapDirections
NHDES publishes the water-quality measurements for Harantis Lake-Deep Spot. Here is what has been measured.
- Mesotrophic
- Impaired · Algal growth
- Limited data
Harantis Lake-Deep Spot in Rockingham County, New Hampshire has water-quality measurements published by NHDES, shown here as reported. Phosphorus: 20.9 µg/L. Chlorophyll-a (algae): 4.2 µg/L. Surface area: 15.4 acres.
Harantis Lake-Deep Spot is a 15-acre mesotrophic lake in Rockingham County, New Hampshire. Compared to the 50 other monitored lakes in Rockingham County, Harantis Lake-Deep Spot ranks #33 for water quality.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2024-07-24. Methodology: how these readings are compared.
Swimming conditions
Readings onlyRecreation use not supported
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. Harantis Lake-Deep Spot is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, mercury, pH / acidity. Check local advisories before you swim.
Whether Harantis 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 Harantis Lake-Deep Spot
These are the measurements NHDES publishes for Harantis 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 20.9 µg/L. Chlorophyll-a 4.2 µg/L. TSI 46.
| 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 | 20.9µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | 4.2µg/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. | 46 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Harantis Lake-Deep Spot
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
15 acres
No bathymetric survey has been published for Harantis Lake-Deep Spot, so its depth is not documented here.
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Fishing Harantis Lake-Deep Spot
Reservoir Info (USACE NID)
Harantis Lake-Deep Spot is a man-made reservoir impounded by the Harantis Lake Dam (completed 1930), built primarily for recreation on the Beaver Brook; concrete-type dam, 14 ft tall and 150 ft long.
- Surface area
- 15.4 ac
- Normal storage
- 77.7 ac-ft
- Max storage
- 145 ac-ft
- Drainage area
- 2.22 sq mi
- Hazard class
- Significant
- Owner
- HARANTIS LAKE PROPERTY OWNERS ASSOC
Source: USACE National Inventory of Dams, NID ID NH00337 · Operator website · Matched by proximity (0.35 km)
EPA Impairment Status
Harantis 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 NHIMP700061203-01 · Official waterbody report
Nearby Lakes in Rockingham County
Frequently asked questions about Harantis Lake-Deep Spot
Where is Harantis Lake-Deep Spot?
- Harantis Lake-Deep Spot is a lake in Rockingham County, New Hampshire. Its water-quality measurements are published by NHDES and shown on this page as reported.
What is the water quality of Harantis Lake-Deep Spot?
- Harantis Lake-Deep Spot in Rockingham County, New Hampshire has water-quality measurements published by NHDES, shown here as reported. Phosphorus: 20.9 µg/L. Chlorophyll-a (algae): 4.2 µg/L. Surface area: 15.4 acres.
Is Harantis Lake-Deep Spot safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Harantis Lake-Deep Spot is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, mercury, pH / acidity. Check local advisories before you swim.
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Where this data comes from
4 measurements from 1 monitoring station, 2021–2024. Retrieved from the EPA Water Quality Portal on 2026-08-21.
Collected and reported by
- New Hampshire Department Of Environmental Services (BEACH)
111133004 samples · 2021–2024
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