Allen Dam is an earth dam located in Middlesex County, Massachusetts, built in 1797. It carries a Low hazard potential classification and has a fair condition assessment.
Dam profile
NID height · 15 ft15 ft tall and 17 ft long. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic embankment section and the water level is illustrative.
About Allen Dam
The primary purpose of Allen Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by William Aird & Marianne Grant (private). It impounds the Nashoba Brook near Acton.
The dam stands 15 feet tall and stretches 17 feet across, has a maximum storage capacity of 154 acre-feet, and collects water from a drainage area of 20 square miles. Completed in 1797, the structure is one of the older dams in the region, with over a century and a half of service.
This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. The most recent inspection on record was 06/25/2009. That was over 17 years ago.
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 | Acton |
| River/Stream | Nashoba Brook |
| Coordinates | 42.47776, -71.41464 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 15 ft |
| Dam Length | 17.8 ft |
| Year Completed | 1797 (229 years old) |
Storage & Hydraulics
| NID Storage | 154 acre-ft |
| Max Storage | 154 acre-ft |
| Normal Storage | 68 acre-ft |
| Drainage Area | 20 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | William Aird & Marianne Grant |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Fair |
| Last Inspection | 06/25/2009 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | MA00127 |
| Federal ID | MA00127 |
| More Info | State Dam Safety Program |