Northwood Lake-Horse Farm
Rockingham County, New HampshireView mapDirections
NHDES publishes the water-quality measurements for Northwood Lake-Horse Farm. Here is what has been measured.
- Eutrophic
- Impaired · Biotoxins
Northwood Lake-Horse Farm in Rockingham County, New Hampshire has water-quality measurements published by NHDES, shown here as reported. Phosphorus: 49.8 µg/L.
Northwood Lake-Horse Farm is a productive, nutrient-rich eutrophic lake in Rockingham County, New Hampshire. Compared to the 50 other monitored lakes in Rockingham County, Northwood Lake-Horse Farm ranks #47 for water quality.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2025-07-23. 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. Northwood Lake-Horse Farm is listed impaired under Clean Water Act §303(d) (IR 5) for biotoxins, mercury, nuisance exotic species, pathogens (E. coli, fecal), pH / acidity. Check local advisories before you swim.
Whether Northwood Lake-Horse Farm 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 Northwood Lake-Horse Farm
These are the measurements NHDES publishes for Northwood Lake-Horse Farm, 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 49.8 µg/L. TSI 61.
| 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 | 49.8µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | No reading 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. | 61 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
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Stays near Northwood Lake-Horse Farm
Compare lakeside cabins, hotels, and vacation rentals near Northwood Lake-Horse Farm 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. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Northwood Lake-Horse Farm are listed below.
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Fishing Northwood Lake-Horse Farm
EPA Impairment Status
Northwood Lake-Horse Farm 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 NHLAK700060502-08-01 · Official waterbody report
Nearby Lakes in Rockingham County
Frequently asked questions about Northwood Lake-Horse Farm
Where is Northwood Lake-Horse Farm?
- Northwood Lake-Horse Farm 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 Northwood Lake-Horse Farm?
- Northwood Lake-Horse Farm in Rockingham County, New Hampshire has water-quality measurements published by NHDES, shown here as reported. Phosphorus: 49.8 µg/L.
Is Northwood Lake-Horse Farm safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Northwood Lake-Horse Farm is listed impaired under Clean Water Act §303(d) (IR 5) for biotoxins, mercury, nuisance exotic species, pathogens (E. coli, fecal), pH / acidity. Check local advisories before you swim.
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Where this data comes from
15 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)
1111330015 samples · 2020–2025
Analytical methods
- 10-115-01-1 F ~ LACHAT; Total Phosphorus- Manual persulfate digest
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