Hamilton Reservoir
Hampden County, Massachusetts400 acresView mapDirections
Clarity, phosphorus, and algae all sit in the cleanest band for this region.
- Mesotrophic
- Impaired · Nuisance exotic species
- #2 of 4 in the county
- 46 ft max depth
- Public access
- Limited data
Hamilton Reservoir in Hampden County, Massachusetts has a water quality grade of A (Excellent). Chlorophyll-a (algae): 3 µg/L. Surface area: 400 acres.
- Max depth
- ~46 ft est.
- Area
- 400 acres
- Type
- Mesotrophic
- Chlorophyll-a
- 3 µg/L
- Public access
- Yes
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Watch Hamilton Reservoir’s letter
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Hamilton Reservoir is a 400-acre mesotrophic lake in Hampden County, Massachusetts with an estimated average depth of about 46 feet. Water quality is graded A based on 1 sampling years through 2016. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 3 other monitored lakes in Hampden County, Hamilton Reservoir ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, MassDEP, last sampled 2016-08-30. Grade methodology: LakeQuality methodology.
What Hamilton Reservoir is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
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.
The A is nutrients and algae, not a swimming clearance. Hamilton Reservoir is listed impaired under Clean Water Act §303(d) (IR 4C) for nuisance exotic species. Check local advisories before you swim.
Water Quality Grade: A (Excellent)
No clarity data. Chlorophyll-a 3 µg/L. TSI 41. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | 3 µg/L | Good |
| Trophic State Index (TSI) | 41 | Mesotrophic |
Moderate nutrients, good water quality
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~46 ft est. |
| Average Depth | ~29 ft est. |
| Surface Area | 400 acres |
| Public Access | Yes |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Massachusetts has not published bathymetry for Hamilton Reservoir.
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Recreation & Access
- Hamilton ReservoirPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Hamilton Reservoir
Reservoir Info (USACE NID)
Hamilton Reservoir is a man-made reservoir impounded by the Hamilton Reservoir Dam, built primarily for recreation on the Quinebaug River; earth-type dam, 17 ft tall and 300 ft long.
- Surface area
- 400 ac
- Normal storage
- 1,918 ac-ft
- Max storage
- 4,200 ac-ft
- Drainage area
- 17.95 sq mi
- Hazard class
- High
- Owner
- Town of Holland
Source: USACE National Inventory of Dams, NID ID MA00536 · Operator website
EPA Impairment Status
Hamilton Reservoir is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 4C).
Causes of impairment
Source: EPA ATTAINS assessment unit MA41019 · Official waterbody report
County Ranking
Ranked #2 of 4 lakes in Hampden County
Nearby Lakes in Hampden County
Frequently asked questions about Hamilton Reservoir
Where is Hamilton Reservoir?
- Hamilton Reservoir is a lake in Hampden County, Massachusetts. LakeQuality grades it A for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Hamilton Reservoir?
- Hamilton Reservoir in Hampden County, Massachusetts has a water quality grade of A (Excellent). Chlorophyll-a (algae): 3 µg/L. Surface area: 400 acres.
Is Hamilton Reservoir safe to swim in?
- The A is nutrients and algae, not a swimming clearance. Hamilton Reservoir is listed impaired under Clean Water Act §303(d) (IR 4C) for nuisance exotic species. Check local advisories before you swim.
How deep is Hamilton Reservoir?
- No published bathymetric survey covers Hamilton Reservoir, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 46 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate. The lake covers 400 acres.
Are there boat ramps on Hamilton Reservoir?
- Hamilton Reservoir has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Hamilton Reservoir. Public access is listed as yes.
Explore Hamilton Reservoir across LakeQuality
Species activity outlook by water temperature and season
Where to stay at Massachusetts's top lakes, each with its grade
Moderate nutrients, good water quality
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Other Grade A Lakes in Massachusetts
Mesotrophic Lakes in Massachusetts
Where this data comes from
3 measurements from 1 monitoring station, 2016. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Massachusetts Department of Environmental Protection (MassDEP)
MASSDEP3 samples · 2016
Analytical methods
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Named boat-access points from the USGS National Boat Ramps inventory