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LakeQuality

Giles Pond-Deep Spot

NR
Not yet rated
Mesotrophic · 43 acres
Limited DataMesotrophic

Giles Pond-Deep Spot in Merrimack County, New Hampshire is not rated for water quality — its monitoring record does not meet the evidence bar. Phosphorus: 13.4 µg/L. Chlorophyll-a (algae): 5.2 µg/L. Surface area: 43 acres.

Area
43 acres
Public access
Yes

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Why Giles Pond-Deep Spot has no grade

We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Giles Pond-Deep Spot, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). Sampling here has recorded phosphorus and algae (chlorophyll-a), but not water clarity.

Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.

Sampling is run by your state environmental agency and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.

Giles Pond-Deep Spot is a 43-acre lake in Merrimack County, New Hampshire. Limited fish-species data available. Public access is available with 1 public boat landing.

Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2020-06-11. Grade methodology: LakeGrade methodology.

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Swimming Safety

Not rated

Limited data

Not rated for swimming — there is not enough monitoring data to judge this lake

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Water quality measurements for Giles Pond-Deep Spot

These readings exist but do not meet the evidence bar for an A–F grade — see why.

No clarity data. Phosphorus level: 13.4 µg/L. Chlorophyll-a: 5.2 µg/L. Trophic State Index: 44.

MetricValueGrade
Water Clarity (Secchi Depth)No recent samples
Phosphorus13.4 µg/LNot graded
Chlorophyll-a (Algae)5.2 µg/LNot graded
Trophic State Index (TSI)44Mesotrophic

Moderate nutrients, good water quality

Where to stay near Giles Pond-Deep Spot

Compare lakeside cabins, hotels, and vacation rentals near Giles Pond-Deep Spot in Merrimack 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 Giles Pond-Deep Spot

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Lake Details

CharacteristicValue
Surface Area43 acres
Public AccessYes

No bathymetric survey has been published for Giles Pond-Deep Spot, so its depth is not documented here.

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Shaw CovePublic

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

Fishing Giles Pond-Deep Spot

Reservoir Info (USACE NID)

Giles Pond-Deep Spot is a man-made reservoir impounded by the Giles Pond (completed 1904), built primarily for hydroelectric on the Salmon Brook; masonry-type dam, 18 ft tall and 245 ft long.

Surface area
43 ac
Normal storage
860 ac-ft
Max storage
860 ac-ft
Drainage area
25 sq mi
Hazard class
Low
Owner
Franklin Falls Hydro Electric Corporation

Source: USACE National Inventory of Dams, NID ID NH00177 · Operator website · Matched by proximity (0.21 km)

EPA Impairment Status

Giles Pond-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

MercurypH / acidity

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

Source: EPA ATTAINS assessment unit NHLAK700010802-02 · Official waterbody report · Matched by proximity (0.62 km)

Graded lakes near Giles Pond-Deep Spot

Giles Pond-Deep Spot has no grade, but these lakes within a short drive do.

Nearby Lakes in Merrimack County

Frequently asked questions about Giles Pond-Deep Spot

Where is Giles Pond-Deep Spot?

Giles Pond-Deep Spot is a lake in Merrimack County, New Hampshire. LakeQuality has not rated this lake (UNRATED) — there is not enough recent sampling to assign a letter.

What is the water quality grade for Giles Pond-Deep Spot?

Giles Pond-Deep Spot in Merrimack County, New Hampshire is not rated for water quality — its monitoring record does not meet the evidence bar. Phosphorus: 13.4 µg/L. Chlorophyll-a (algae): 5.2 µg/L. Surface area: 43 acres.

Is Giles Pond-Deep Spot safe to swim in?

Not rated for swimming — there is not enough monitoring data to judge this lake. Giles Pond-Deep Spot is not rated for water quality — its monitoring record does not meet the evidence bar. Algae concentration (chlorophyll-a) is 5.2 µg/L. Always check local health department advisories before swimming.

Are there boat ramps on Giles Pond-Deep Spot?

Giles Pond-Deep Spot has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Shaw Cove. Public access is listed as yes.

Where this data comes from

2 measurements from 1 monitoring station, 2020. Retrieved from the EPA Water Quality Portal on 2026-08-21.

Collected and reported by

  • New Hampshire Department Of Environmental Services (BEACH)111133002 samples · 2020

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