Maxwell Locks And Dam
Maxwell Locks And Dam is a gravity dam located in Washington County, Pennsylvania, built in 1964. It carries a Significant hazard potential classification.
About Maxwell Locks And Dam
The primary purpose of Maxwell Locks And Dam 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 Monongahela River near Brownsville.
The dam stands 56 feet tall and stretches 692 feet across, creates a reservoir covering 1,380 acres, has a maximum storage capacity of 30,900 acre-feet, and collects water from a drainage area of 4,961 square miles. Completed in 1964, 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. An emergency action plan is in place for this dam. The most recent inspection on record was 08/27/2025.
At 56 feet, this dam is taller than 94% of dams nationwide.
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Location
| State | Pennsylvania |
| County | Washington |
| Nearest City | Brownsville |
| River/Stream | Monongahela River |
| Coordinates | 40.00227, -79.95964 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 56 ft |
| Dam Length | 692 ft |
| Year Completed | 1964 (62 years old) |
Storage & Hydraulics
| NID Storage | 30,900 acre-ft |
| Max Storage | 30,900 acre-ft |
| Normal Storage | 30,900 acre-ft |
| Surface Area | 1,380 acres |
| Drainage Area | 4,961 sq mi |
| Max Discharge | 120,000 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Navigation |
| Owner | USACE - Pittsburgh District |
| Owner Type | Federal |
| Hazard Classification | Significant |
| Condition Assessment | Not Available |
| Last Inspection | 08/27/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | PA00123 |
| Federal ID | PA00123 |
| More Info | State Dam Safety Program |