Rock Island
Rock Island is a concrete dam located in Lewis County, New York, built in 1984. It carries a Low hazard potential classification and has a satisfactory condition assessment.
About Rock Island
The primary purpose of Rock Island 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 18 feet tall and stretches 180 feet across, creates a reservoir covering 8 acres, has a maximum storage capacity of 50 acre-feet, and collects water from a drainage area of 429 square miles. Completed in 1984, the structure is 42 years 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.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | New York |
| County | Lewis |
| Nearest City | Port Leyden |
| River/Stream | Black River |
| Coordinates | 43.58660, -75.33910 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 18 ft |
| Dam Height | 18 ft |
| Dam Length | 180 ft |
| Year Completed | 1984 (42 years old) |
Storage & Hydraulics
| NID Storage | 50 acre-ft |
| Max Storage | 50 acre-ft |
| Normal Storage | 50 acre-ft |
| Surface Area | 8 acres |
| Drainage Area | 429 sq mi |
| Max Discharge | 18,500 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 | NY12231 |
| Federal ID | NY12231 |
| More Info | State Dam Safety Program |