Iroquois
Iroquois is a concrete dam located in St. Lawrence County, New York, built in 1958. It carries a Significant hazard potential classification and has a satisfactory condition assessment.
About Iroquois
The primary purpose of Iroquois 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 New York Power Authority (state). It impounds the St. Lawrence River near Waddington.
The dam stands 72 feet tall and stretches 1,980 feet across, creates a reservoir covering 37,500 acres, has a maximum storage capacity of 803,000 acre-feet, and collects water from a drainage area of 300,000 square miles. Completed in 1958, 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 satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 08/04/2022.
At 72 feet, this dam is taller than 96% of all dams in the United States.
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Location
| State | New York |
| County | St. Lawrence |
| Nearest City | Waddington |
| River/Stream | St. Lawrence River |
| Coordinates | 44.83480, -75.30360 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 72 ft |
| Dam Height | 67 ft |
| Dam Length | 1,980 ft |
| Year Completed | 1958 (68 years old) |
Storage & Hydraulics
| NID Storage | 803,000 acre-ft |
| Max Storage | 803,000 acre-ft |
| Normal Storage | 750,000 acre-ft |
| Surface Area | 37,500 acres |
| Drainage Area | 300,000 sq mi |
| Max Discharge | 385,000 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Hydroelectric |
| Owner | New York Power Authority |
| Owner Type | State |
| Hazard Classification | Significant |
| Condition Assessment | Satisfactory |
| Last Inspection | 08/04/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | NY00676 |
| Federal ID | NY00678S003 |
| More Info | State Dam Safety Program |