Allegheny River Lock And Dam 9
Allegheny River Lock And Dam 9 is a gravity dam located in Armstrong County, Pennsylvania, built in 1938. It carries a Low hazard potential classification.
About Allegheny River Lock And Dam 9
The primary purpose of Allegheny River Lock And Dam 9 is navigation. The dam maintains water levels sufficient for boat and barge traffic, supporting commercial or recreational navigation on the waterway. The dam is owned by Usace - Pittsburgh District (federal). It impounds the Allegheny River near Rimer.
The dam stands 55 feet tall and stretches 1,040 feet across, creates a reservoir covering 1,040 acres, has a maximum storage capacity of 13,500 acre-feet, and collects water from a drainage area of 8,401 square miles. Completed in 1938, the structure is well-established, with more than 75 years of service.
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. An emergency action plan is in place for this dam. The most recent inspection on record was 09/20/2024.
At 55 feet, this dam is taller than 94% of dams nationwide.
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Location
| State | Pennsylvania |
| County | Armstrong |
| Nearest City | Rimer |
| River/Stream | Allegheny River |
| Coordinates | 40.95627, -79.54876 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 55 ft |
| Dam Length | 1,040 ft |
| Year Completed | 1938 (88 years old) |
Storage & Hydraulics
| NID Storage | 13,500 acre-ft |
| Max Storage | 13,500 acre-ft |
| Normal Storage | 13,500 acre-ft |
| Surface Area | 1,040 acres |
| Drainage Area | 8,401 sq mi |
| Max Discharge | 125,000 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Navigation |
| Owner | USACE - Pittsburgh District |
| Owner Type | Federal |
| Hazard Classification | Low |
| Condition Assessment | Not Available |
| Last Inspection | 09/20/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | PA00119 |
| Federal ID | PA00119 |
| More Info | State Dam Safety Program |