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Partridge Lake-Deep Spot

C
Grade C — Fair
Fair · #24 of 27 lakes in the county · Mesotrophic
Mesotrophic

Partridge Lake-Deep Spot in Grafton County, New Hampshire has a water quality grade of C (Fair). Phosphorus: 16.9 µg/L. Chlorophyll-a (algae): 6.4 µg/L.

Type
Mesotrophic
Public access
Yes

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Partridge Lake-Deep Spot is a mesotrophic lake in Grafton County, New Hampshire. Water quality is graded C based on 2 sampling years through 2025. Limited fish-species data available. Public access is available with 5 public boat landings. Compared to the 26 other monitored lakes in Grafton County, Partridge Lake-Deep Spot ranks #24 for water quality.

Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2025-08-20. Grade methodology: LakeGrade methodology.

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Swimming Safety

Grade only

Bacteria advisory

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.

Generally safe for swimming, moderate water quality

Get alerts for Partridge Lake-Deep Spot

Water Quality Grade: C (Fair)

No clarity data. Phosphorus level: 16.9 µg/L. Chlorophyll-a: 6.4 µg/L. Trophic State Index: 47.

MetricValueGrade
Water Clarity (Secchi Depth)No recent samples
Phosphorus16.9 µg/LFair
Chlorophyll-a (Algae)6.4 µg/LFair
Trophic State Index (TSI)47Mesotrophic

Moderate nutrients, good water quality

Where to stay near Partridge Lake-Deep Spot

Compare lakeside cabins, hotels, and vacation rentals near Partridge Lake-Deep Spot in Grafton 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.

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Recreation & Access

5
Boat Landings
Yes
Public Access
  • Moore Dam Visitor CenterPublic
  • Waterford BridgePublic
  • Dodge HillPublic
  • Pattenville Picnic AreaPublic
  • Pine IslandPublic

Named access points from the USGS National Boat Ramps inventory, snapped within 5 km. More lakes with boat ramps

Fishing Partridge Lake-Deep Spot

EPA Impairment Status

Partridge 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

BiotoxinsMercurypH / acidity

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit NHLAK801030502-03 · Official waterbody report · Matched by proximity (0.41 km)

County Ranking

Ranked #24 of 27 lakes in Grafton County

Nearby Lakes in Grafton County

Frequently asked questions about Partridge Lake-Deep Spot

Where is Partridge Lake-Deep Spot?

Partridge Lake-Deep Spot is a lake in Grafton County, New Hampshire. LakeQuality grades it C for nutrients and algae. The letter is not a swimming clearance.

What is the water quality grade for Partridge Lake-Deep Spot?

Partridge Lake-Deep Spot in Grafton County, New Hampshire has a water quality grade of C (Fair). Phosphorus: 16.9 µg/L. Chlorophyll-a (algae): 6.4 µg/L.

Is Partridge Lake-Deep Spot safe to swim in?

Generally safe for swimming, moderate water quality. Partridge Lake-Deep Spot has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 6.4 µg/L. Always check local health department advisories before swimming.

Are there boat ramps on Partridge Lake-Deep Spot?

Partridge Lake-Deep Spot has 5 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Moore Dam Visitor Center, Waterford Bridge, Dodge Hill, Pattenville Picnic Area, among others. Public access is listed as yes.

Where this data comes from

65 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)1111330065 samples · 2020–2025

Analytical methods

  • 10-115-01-1 F ~ LACHAT; Total Phosphorus- Manual persulfate digest
  • CHLOROPHYLL A-B-C DETERMINATION (MODIFIED)
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

Named boat-access points from the USGS National Boat Ramps inventory