Horn Pond
Middlesex County, Massachusetts103 acresView mapDirections
Nutrients and algae run above the regional average.
↓ down from C at the last regrade
- Eutrophic
- Impaired · Algal growth
- #8 of 11 in the county
- 39 ft max depth
- Public access
- Limited data
Horn Pond in Middlesex County, Massachusetts has a water quality grade of D (Nutrient-rich). Chlorophyll-a (algae): 13.4 µg/L. Surface area: 103 acres.
- Max depth
- ~39 ft est.
- Area
- 103 acres
- Type
- Eutrophic
- Chlorophyll-a
- 13.4 µg/L
- Public access
- Yes
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Stays near Horn Pond
Compare lakeside cabins, hotels, and vacation rentals near Horn Pond in Middlesex County, Massachusetts — 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 Horn Pond are listed below.
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Watch Horn Pond’s letter
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Horn Pond is a 103-acre productive, nutrient-rich eutrophic lake in Middlesex County, Massachusetts with an estimated average depth of about 39 feet. Water quality is graded D based on 1 sampling years through 2019. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 10 other monitored lakes in Middlesex County, Horn Pond ranks #8 for water quality.
Source: EPA Water Quality Portal sampling records, MassDEP, last sampled 2019-10-29. Grade methodology: LakeQuality methodology.
What Horn Pond 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 D is nutrients and algae, not a swimming clearance. Horn Pond is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, habitat alterations, nutrients (phosphorus, nitrogen), oxygen depletion (low DO), pesticides. Check local advisories before you swim.
Water Quality Grade: D (Nutrient-rich)
No clarity data. Chlorophyll-a 13.4 µg/L. TSI 56. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | 13.4 µg/L | Poor |
| Trophic State Index (TSI) | 56 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~39 ft est. |
| Average Depth | ~13 ft est. |
| Surface Area | 103 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 Horn Pond.
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
- Horn PondPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Horn Pond
Reservoir Info (USACE NID)
Horn Pond is a man-made reservoir impounded by the Horn Pond Dam (completed 1989), built primarily for water supply on the Horn Pond Brook, tributary to Aberjona River; earth-type dam, 15 ft tall and 330 ft long.
- Surface area
- 103 ac
- Normal storage
- 840 ac-ft
- Max storage
- 1,508 ac-ft
- Drainage area
- 9.36 sq mi
- Hazard class
- Significant
- Owner
- City of Woburn
All listed purposes: Water Supply;Recreation.
Source: USACE National Inventory of Dams, NID ID MA01124 · Operator website
EPA Impairment Status
Horn Pond is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit MA71019 · Official waterbody report
County Ranking
Ranked #8 of 11 lakes in Middlesex County
Nearby Lakes in Middlesex County
Frequently asked questions about Horn Pond
Where is Horn Pond?
- Horn Pond is a lake in Middlesex County, Massachusetts. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Horn Pond?
- Horn Pond in Middlesex County, Massachusetts has a water quality grade of D (Nutrient-rich). Chlorophyll-a (algae): 13.4 µg/L. Surface area: 103 acres.
Is Horn Pond safe to swim in?
- The D is nutrients and algae, not a swimming clearance. Horn Pond is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, habitat alterations, nutrients (phosphorus, nitrogen), oxygen depletion (low DO), pesticides. Check local advisories before you swim.
How deep is Horn Pond?
- No published bathymetric survey covers Horn Pond, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 39 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 103 acres.
Are there boat ramps on Horn Pond?
- Horn Pond has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Horn Pond. Public access is listed as yes.
Explore Horn Pond across LakeQuality
Species activity outlook by water temperature and season
Where to stay at Massachusetts's top lakes, each with its grade
High nutrients, frequent algae, reduced clarity
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Other Grade D Lakes in Massachusetts
Eutrophic Lakes in Massachusetts
Where this data comes from
5 measurements from 1 monitoring station, 2019. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Massachusetts Department of Environmental Protection (MassDEP)
MASSDEP5 samples · 2019
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