Lake Williams Dam
Lake Williams Dam is an earth dam located in Middlesex County, Massachusetts, built in 1882. It carries a High hazard potential classification and has a fair condition assessment.
About Lake Williams Dam
Lake Williams Dam is a dam in Middlesex, Massachusetts. The dam is owned by City Of Marlborough (local government). It impounds the Assabet River near Marlborough.
The dam stands 11 feet tall and stretches 270 feet across, creates a reservoir covering 72 acres, has a maximum storage capacity of 767 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1882, 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 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 05/24/2023.
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 | Middlesex |
| Nearest City | Marlborough |
| River/Stream | Assabet River |
| Coordinates | 42.33633, -71.57162 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 11 ft |
| Dam Length | 270 ft |
| Year Completed | 1882 (144 years old) |
Storage & Hydraulics
| NID Storage | 767 acre-ft |
| Max Storage | 767 acre-ft |
| Normal Storage | 576 acre-ft |
| Surface Area | 72 acres |
| Drainage Area | 0 sq mi |
| Max Discharge | 55 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Owner | City of Marlborough |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Fair |
| Last Inspection | 05/24/2023 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MA00451 |
| Federal ID | MA00451 |
| More Info | State Dam Safety Program |