Sandy Hook is a gravity dam located in Fairfield County, Connecticut, built in 1905. It carries a Significant hazard potential classification and has a satisfactory condition assessment.
Dam profile
NID height · 35 ft35 ft tall and 130 ft long, taller than 80% 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 Sandy Hook
The primary purpose of Sandy Hook 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 Sandy Hook Hydro LLC (private). It impounds the Pootatuck River near Rocky Glen.
The dam stands 35 feet tall and stretches 130 feet across, creates a reservoir covering 4 acres, has a maximum storage capacity of 60 acre-feet, and collects water from a drainage area of 25 square miles. Completed in 1905, the structure is over a century 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 satisfactory, indicating no existing or potential dam safety deficiencies are recognized. The most recent inspection on record was 06/13/2023.
At 35 feet, this dam is taller than 80% of dams nationwide.
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Location
| State | Connecticut |
| County | Fairfield |
| Nearest City | Rocky Glen |
| River/Stream | Pootatuck River |
| Coordinates | 41.43310, -73.27660 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 35 ft |
| Dam Height | 35 ft |
| Dam Length | 130 ft |
| Year Completed | 1905 (121 years old) |
Storage & Hydraulics
| NID Storage | 60 acre-ft |
| Max Storage | 60 acre-ft |
| Normal Storage | 60 acre-ft |
| Surface Area | 4 acres |
| Drainage Area | 25 sq mi |
| Max Discharge | 4,280 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Hydroelectric |
| Owner | Sandy Hook Hydro LLC |
| Owner Type | Private |
| Hazard Classification | Significant |
| Condition Assessment | Satisfactory |
| Last Inspection | 06/13/2023 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | CT00310 |
| Federal ID | CT00310 |
| More Info | State Dam Safety Program |