Gilman is a concrete dam located in Coos County, New Hampshire, built in 1898. It carries a Low hazard potential classification and has a satisfactory condition assessment.
Dam profile
NID height · 38 ft38 ft tall and 319 ft long, taller than 84% of U.S. dams with a recorded height. 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 Gilman
The primary purpose of Gilman is hydroelectric. The dam generates hydroelectric power by channeling water through turbines, converting the energy of flowing water into electricity. The dam is owned by Ampersand Gilman Hydro LP (private). It impounds the Connecticut River near Dalton, Nh.
The dam stands 38 feet tall and stretches 319 feet across, creates a reservoir covering 130 acres, has a maximum storage capacity of 705 acre-feet, and collects water from a drainage area of 1,514 square miles. Completed in 1898, the structure is over a century old.
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 satisfactory, indicating no existing or potential dam safety deficiencies are recognized. The most recent inspection on record was 06/12/2017.
At 38 feet, this dam is taller than 84% of dams nationwide.
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Location
| State | New Hampshire |
| County | Coos |
| Nearest City | Dalton, Nh |
| River/Stream | Connecticut River |
| Coordinates | 44.40980, -71.71770 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 38 ft |
| Dam Height | 38 ft |
| Dam Length | 319 ft |
| Year Completed | 1898 (128 years old) |
Storage & Hydraulics
| NID Storage | 705 acre-ft |
| Max Storage | 705 acre-ft |
| Normal Storage | 705 acre-ft |
| Surface Area | 130 acres |
| Drainage Area | 1,514 sq mi |
| Max Discharge | 3,538 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Hydroelectric |
| Owner | Ampersand Gilman Hydro LP |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Satisfactory |
| Last Inspection | 06/12/2017 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | NH00366 |
| Federal ID | NH00366 |
| More Info | State Dam Safety Program |