Deering Lake-Morrotta Bay
Deering Lake-Morrotta Bay in Hillsborough County, New Hampshire has a water quality grade of B (Good). Phosphorus: 9.5 µg/L.
- Type
- Oligotrophic
Deering Lake-Morrotta Bay is a cold, clear oligotrophic lake in Hillsborough County, New Hampshire. Water quality is graded B based on 1 sampling years through 2025. Compared to the 35 other monitored lakes in Hillsborough County, Deering Lake-Morrotta Bay ranks #15 for water quality.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2025-08-05. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLimited data
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.
Good for swimming, clear water with low algae levels
Water Quality Grade: B (Good)
No clarity data. Phosphorus level: 9.5 µg/L. Trophic State Index: 37.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | 9.5 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 37 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Deering Lake-Morrotta Bay
Compare lakeside cabins, hotels, and vacation rentals near Deering Lake-Morrotta Bay in Hillsborough 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.
Top-rated places to stay near Deering Lake-Morrotta Bay
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Fishing Deering Lake-Morrotta Bay
EPA Impairment Status
Deering Lake-Morrotta Bay is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit NHLAK700060601-01 · Official waterbody report · Matched by proximity (0.83 km)
County Ranking
Ranked #15 of 36 lakes in Hillsborough County
Nearby Lakes in Hillsborough County
Frequently asked questions about Deering Lake-Morrotta Bay
Where is Deering Lake-Morrotta Bay?
- Deering Lake-Morrotta Bay is a lake in Hillsborough County, New Hampshire. LakeQuality grades it B for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Deering Lake-Morrotta Bay?
- Deering Lake-Morrotta Bay in Hillsborough County, New Hampshire has a water quality grade of B (Good). Phosphorus: 9.5 µg/L.
Is Deering Lake-Morrotta Bay safe to swim in?
- Good for swimming, clear water with low algae levels. Deering Lake-Morrotta Bay has a water quality grade of B (Good). Always check local health department advisories before swimming.
Explore Deering Lake-Morrotta Bay across LakeGrade
More New Hampshire Lake Rankings
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Top 25 by Secchi water clarity
Grade A/B + low algae filter
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Other Grade B Lakes in New Hampshire
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Oligotrophic Lakes in New Hampshire
Where this data comes from
6 measurements from 1 monitoring station, 2024–2025. Retrieved from the EPA Water Quality Portal on 2026-08-21.
Collected and reported by
- New Hampshire Department Of Environmental Services (BEACH)
111133006 samples · 2024–2025
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