Northwood Lake-Horse Farm
Northwood Lake-Horse Farm in Rockingham County, New Hampshire has a water quality grade of D (Nutrient-rich). Phosphorus: 49.8 µg/L.
- Type
- Eutrophic
Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Northwood Lake-Horse Farm →
Northwood Lake-Horse Farm is a productive, nutrient-rich eutrophic lake in Rockingham County, New Hampshire. Water quality is graded D based on 1 sampling years through 2025. 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. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyElevated nutrients
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum
Water Quality Grade: D (Nutrient-rich)
No clarity data. Phosphorus level: 49.8 µg/L. Trophic State Index: 61.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | 49.8 µg/L | Poor |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 61 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay 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 grade measures nutrients and algae, not lodging — cabins and rentals around Northwood Lake-Horse Farm are listed below.
Top-rated places to stay near Northwood Lake-Horse Farm
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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 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit NHLAK700060502-08-03 · Official waterbody report · Matched by proximity (0.57 km)
County Ranking
Ranked #47 of 51 lakes in Rockingham County
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. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Northwood Lake-Horse Farm?
- Northwood Lake-Horse Farm in Rockingham County, New Hampshire has a water quality grade of D (Nutrient-rich). Phosphorus: 49.8 µg/L.
Is Northwood Lake-Horse Farm safe to swim in?
- Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum. Northwood Lake-Horse Farm has a water quality grade of D (Nutrient-rich). Always check local health department advisories before swimming.
Explore Northwood Lake-Horse Farm 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 Grade D Lakes in New Hampshire
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Hillsborough County · Nutrient-rich
Hillsborough County · Nutrient-rich
Hillsborough County · Nutrient-rich
Hillsborough County · Nutrient-rich
Hillsborough County · Nutrient-rich
Eutrophic Lakes in New Hampshire
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)
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