Lighthouse Hill
Lighthouse Hill is a concrete dam located in Oswego County, New York, built in 1930. It carries a High hazard potential classification and has a fair condition assessment.
About Lighthouse Hill
The primary purpose of Lighthouse Hill is hydroelectric. The dam generates hydroelectric power by channeling water through turbines, converting the energy of flowing water into electricity. It impounds the Salmon River near Altmar.
The dam stands 47 feet tall and stretches 851 feet across, creates a reservoir covering 170 acres, has a maximum storage capacity of 3,870 acre-feet, and collects water from a drainage area of 198 square miles. Completed in 1930, the structure is well-established, with more than 75 years of service.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 08/30/2022.
At 47 feet, this dam is taller than 92% of dams nationwide.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The New York dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | New York |
| County | Oswego |
| Nearest City | Altmar |
| River/Stream | Salmon River |
| Coordinates | 43.52450, -75.97060 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 47 ft |
| Dam Height | 47 ft |
| Dam Length | 851 ft |
| Year Completed | 1930 (96 years old) |
Storage & Hydraulics
| NID Storage | 3,870 acre-ft |
| Max Storage | 3,870 acre-ft |
| Normal Storage | 3,200 acre-ft |
| Surface Area | 170 acres |
| Drainage Area | 198 sq mi |
| Max Discharge | 25,300 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Hydroelectric |
| Owner Type | Not Listed |
| Hazard Classification | High |
| Condition Assessment | Fair |
| Last Inspection | 08/30/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | NY00367 |
| Federal ID | NY00367 |
| More Info | State Dam Safety Program |