Denley is a concrete dam located in Lewis County, New York, built in 1912. It carries a Low hazard potential classification and has a satisfactory condition assessment.
Dam profile
NID height · 29 ft29 ft tall and 350 ft long, taller than 65% 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 Denley
The primary purpose of Denley is hydroelectric. The dam generates hydroelectric power by channeling water through turbines, converting the energy of flowing water into electricity. It impounds the Black River near Port Leyden.
The dam stands 29 feet tall and stretches 350 feet across, creates a reservoir covering 41 acres, has a maximum storage capacity of 350 acre-feet, and collects water from a drainage area of 398 square miles. Completed in 1912, 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 09/19/2019.
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Location
| State | New York |
| County | Lewis |
| Nearest City | Port Leyden |
| River/Stream | Black River |
| Coordinates | 43.54530, -75.32510 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 29 ft |
| Dam Height | 29 ft |
| Dam Length | 350 ft |
| Year Completed | 1912 (114 years old) |
Storage & Hydraulics
| NID Storage | 350 acre-ft |
| Max Storage | 350 acre-ft |
| Normal Storage | 350 acre-ft |
| Surface Area | 41 acres |
| Drainage Area | 398 sq mi |
| Max Discharge | 17,400 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Hydroelectric |
| Owner Type | Not Listed |
| Hazard Classification | Low |
| Condition Assessment | Satisfactory |
| Last Inspection | 09/19/2019 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | NY00310 |
| Federal ID | NY00310 |
| More Info | State Dam Safety Program |