Sudbury Reservoir Dam
Sudbury Reservoir Dam is an earth dam located in Worcester County, Massachusetts, built in 1899. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Sudbury Reservoir Dam
The primary purpose of Sudbury Reservoir Dam is water supply. The dam stores water for municipal, industrial, or agricultural use, helping ensure a reliable supply for the surrounding area. The dam is owned by Ma Department Of Conservation & Recreation (state). It impounds the Stony Brook near Southborough.
The dam stands 77 feet tall and stretches 2,000 feet across, creates a reservoir covering 1,280 acres, has a maximum storage capacity of 33,020 acre-feet, and collects water from a drainage area of 22 square miles. Completed in 1899, the structure is over a century old.
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 11/01/2022.
At 77 feet, this dam is taller than 97% of all dams in the United States.
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 | Worcester |
| Nearest City | Southborough |
| River/Stream | Stony Brook |
| Coordinates | 42.30783, -71.49231 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 77 ft |
| Dam Length | 2,000 ft |
| Year Completed | 1899 (127 years old) |
Storage & Hydraulics
| NID Storage | 33,020 acre-ft |
| Max Storage | 33,020 acre-ft |
| Normal Storage | 22,260 acre-ft |
| Surface Area | 1,280 acres |
| Drainage Area | 22 sq mi |
| Max Discharge | 23,200 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Water Supply |
| Owner | MA Department of Conservation & Recreation |
| Owner Type | State |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 11/01/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MA00741 |
| Federal ID | MA00741 |
| More Info | State Dam Safety Program |