Lake Shirley Dam
Lake Shirley Dam is an earth dam located in Worcester County, Massachusetts, built in 1852. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Lake Shirley Dam
The primary purpose of Lake Shirley 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 Lunenberg (local government). It impounds the Catacoonnamaug Brook near Lunenburg.
The dam stands 21 feet tall and stretches 420 feet across, creates a reservoir covering 390 acres, has a maximum storage capacity of 7,719 acre-feet, and collects water from a drainage area of 14 square miles. Completed in 1852, 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 11/07/2023.
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 | Lunenburg |
| River/Stream | Catacoonnamaug Brook |
| Coordinates | 42.55434, -71.67510 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 21 ft |
| Dam Length | 420 ft |
| Year Completed | 1852 (174 years old) |
Storage & Hydraulics
| NID Storage | 7,719 acre-ft |
| Max Storage | 7,719 acre-ft |
| Normal Storage | 2,969 acre-ft |
| Surface Area | 390 acres |
| Drainage Area | 14 sq mi |
| Max Discharge | 3,570 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | Town of Lunenberg |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 11/07/2023 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MA00455 |
| Federal ID | MA00455 |
| More Info | State Dam Safety Program |