Upper Reservoir Dam is a gravity dam located in Worcester County, Massachusetts. It carries a Significant hazard potential classification and has a fair condition assessment.
Dam profile
NID height · 12 ft12 ft tall and 300 ft long. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic concrete gravity section and the water level is illustrative.
About Upper Reservoir Dam
The primary purpose of Upper Reservoir 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 Westminster (local government). It impounds the Tributary to Mahoney Brook near Westminster.
The dam stands 12 feet tall and stretches 300 feet across, creates a reservoir covering 46 acres, has a maximum storage capacity of 440 acre-feet, and collects water from a drainage area of 1 square miles.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in 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. An emergency action plan is in place for this dam. The most recent inspection on record was 08/09/2023.
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Location
| State | Massachusetts |
| County | Worcester |
| Nearest City | Westminster |
| River/Stream | Tributary to Mahoney Brook |
| Coordinates | 42.53831, -71.96744 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 12 ft |
| Dam Length | 300 ft |
Storage & Hydraulics
| NID Storage | 440 acre-ft |
| Max Storage | 440 acre-ft |
| Normal Storage | 150 acre-ft |
| Surface Area | 46 acres |
| Drainage Area | 1 sq mi |
| Max Discharge | 100 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | Town of Westminster |
| Owner Type | Local Government |
| Hazard Classification | Significant |
| Condition Assessment | Fair |
| Last Inspection | 08/09/2023 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MA00850 |
| Federal ID | MA00850 |
| More Info | State Dam Safety Program |