John P. Murtha Locks and Dam is a gravity dam located in Westmoreland County, Pennsylvania, built in 1967. It carries a Significant hazard potential classification.
Dam profile
NID height · 40 ft40 ft tall and 701 ft long, taller than 86% of U.S. dams with a recorded height. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic concrete gravity section and the water level is illustrative.
About John P. Murtha Locks and Dam
The primary purpose of John P. Murtha 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 Monessen.
The dam stands 40 feet tall and stretches 701 feet across, creates a reservoir covering 1,660 acres, has a maximum storage capacity of 25,100 acre-feet, and collects water from a drainage area of 5,214 square miles. Completed in 1967, 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 10/04/2021.
At 40 feet, this dam is taller than 86% of dams nationwide.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Pennsylvania |
| County | Westmoreland |
| Nearest City | Monessen |
| River/Stream | Monongahela River |
| Coordinates | 40.14654, -79.89951 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 40 ft |
| Dam Length | 701 ft |
| Year Completed | 1967 (59 years old) |
Storage & Hydraulics
| NID Storage | 25,100 acre-ft |
| Max Storage | 25,100 acre-ft |
| Normal Storage | 25,100 acre-ft |
| Surface Area | 1,660 acres |
| Drainage Area | 5,214 sq mi |
| Max Discharge | 100,000 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Navigation |
| Owner | USACE - Pittsburgh District |
| Owner Type | Federal |
| Hazard Classification | Significant |
| Condition Assessment | Not assessed |
| Last Inspection | 10/04/2021 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | PA00122 |
| Federal ID | PA00122 |
| More Info | State Dam Safety Program |