Pontoosuc Lake Dam
Pontoosuc Lake Dam is a concrete dam located in Berkshire County, Massachusetts, built in 1866. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Pontoosuc Lake Dam
The primary purpose of Pontoosuc Lake Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Division Of Capital Asset Management And Maintenance (state). It impounds the West Branch Housatonic River near Pittsfield.
The dam stands 20 feet tall and stretches 150 feet across, creates a reservoir covering 525 acres, has a maximum storage capacity of 5,000 acre-feet, and collects water from a drainage area of 21 square miles. Completed in 1866, 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 05/22/2023.
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 | Berkshire |
| Nearest City | Pittsfield |
| River/Stream | West Branch Housatonic River |
| Coordinates | 42.48418, -73.24656 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 20 ft |
| Dam Length | 150 ft |
| Year Completed | 1866 (160 years old) |
Storage & Hydraulics
| NID Storage | 5,000 acre-ft |
| Max Storage | 5,000 acre-ft |
| Normal Storage | 2,650 acre-ft |
| Surface Area | 525 acres |
| Drainage Area | 21 sq mi |
| Max Discharge | 1,660 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | Division of Capital Asset Management and Maintenance |
| Owner Type | State |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 05/22/2023 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MA00309 |
| Federal ID | MA00309 |
| More Info | State Dam Safety Program |