Mountain Brook Reservoir Dam is an earth dam located in Cheshire County, New Hampshire, built in 1951. It carries a Significant hazard potential classification and has a fair condition assessment.
Dam profile
NID height · 18 ft18 ft tall and 265 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 Mountain Brook Reservoir Dam
The primary purpose of Mountain Brook 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 Jaffrey (local government). It impounds the Mountain Brook near Jaffrey.
The dam stands 18 feet tall and stretches 265 feet across, creates a reservoir covering 91 acres, has a maximum storage capacity of 2,736 acre-feet, and collects water from a drainage area of 13 square miles. Completed in 1951, the structure is well into its service life at over 50 years old.
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 09/02/2022.
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Location
| State | New Hampshire |
| County | Cheshire |
| Nearest City | Jaffrey |
| River/Stream | Mountain Brook |
| Coordinates | 42.80270, -72.02880 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 18 ft |
| Dam Height | 18 ft |
| Dam Length | 265 ft |
| Year Completed | 1951 (75 years old) |
Storage & Hydraulics
| NID Storage | 2,736 acre-ft |
| Max Storage | 2,736 acre-ft |
| Normal Storage | 266 acre-ft |
| Surface Area | 91 acres |
| Drainage Area | 13 sq mi |
| Max Discharge | 3,150 cfs |
Ownership & Safety
| Purpose | Recreation |
| Owner | Town of Jaffrey |
| Owner Type | Local Government |
| Hazard Classification | Significant |
| Condition Assessment | Fair |
| Last Inspection | 09/02/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | NH00099 |
| Federal ID | NH00099 |
| More Info | State Dam Safety Program |