Stony Brook Dam
Stony Brook Dam is an earth dam located in Middlesex County, Massachusetts, built in 1870. It carries a Significant hazard potential classification and has a fair condition assessment.
About Stony Brook Dam
The primary purpose of Stony Brook Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Town Of Westford (local government). It impounds the Stony Brook near Westford.
The dam stands 24 feet tall and stretches 350 feet across, creates a reservoir covering 6 acres, has a maximum storage capacity of 120 acre-feet, and collects water from a drainage area of 26 square miles. Completed in 1870, the structure is one of the older dams in the region, with over a century and a half of service.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 10/20/2021.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Massachusetts |
| County | Middlesex |
| Nearest City | Westford |
| River/Stream | Stony Brook |
| Coordinates | 42.59591, -71.46619 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 24 ft |
| Dam Length | 350 ft |
| Year Completed | 1870 (156 years old) |
Storage & Hydraulics
| NID Storage | 120 acre-ft |
| Max Storage | 120 acre-ft |
| Normal Storage | 61 acre-ft |
| Surface Area | 6 acres |
| Drainage Area | 26 sq mi |
| Max Discharge | 927 cfs |
Ownership & Safety
| Purpose | Recreation |
| Owner | Town of Westford |
| Owner Type | Local Government |
| Hazard Classification | Significant |
| Condition Assessment | Fair |
| Last Inspection | 10/20/2021 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MA00132 |
| Federal ID | MA00132 |
| More Info | State Dam Safety Program |