Greenwood Lake Dam
Greenwood Lake Dam is a rockfill dam located in Bristol County, Massachusetts, built in 1854. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Greenwood Lake Dam
The primary purpose of Greenwood Lake Dam is fish and wildlife pond. The dam creates habitat for fish and wildlife, supporting local ecosystems and potentially serving conservation goals. The dam is owned by Us Fish And Wildlife Service (federal). It impounds the Bungay River near North Attleboro.
The dam stands 18 feet tall and stretches 600 feet across, creates a reservoir covering 128 acres, has a maximum storage capacity of 626 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1854, the structure is one of the older dams in the region, with over a century and a half of service.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 09/21/2015. That was 10 years ago — unusually long for a high-hazard dam, which typically requires more frequent inspections.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Massachusetts dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Massachusetts |
| County | Bristol |
| Nearest City | North Attleboro |
| River/Stream | Bungay River |
| Coordinates | 41.99333, -71.28333 |
Physical Characteristics
| Dam Type | Rockfill |
| NID Height | 18 ft |
| Dam Height | 12 ft |
| Dam Length | 600 ft |
| Year Completed | 1854 (172 years old) |
Storage & Hydraulics
| NID Storage | 626 acre-ft |
| Max Storage | 626 acre-ft |
| Normal Storage | 361 acre-ft |
| Surface Area | 128 acres |
| Drainage Area | 1 sq mi |
| Max Discharge | 2,009 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Fish and Wildlife Pond |
| Owner | US FISH AND WILDLIFE SERVICE |
| Owner Type | Federal |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 09/21/2015 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MA00855 |
| Federal ID | MA00855 |
| More Info | State Dam Safety Program |