Seph Mack is an earth dam located in Indiana County, Pennsylvania, built in 1987. It carries a Significant hazard potential classification.
Dam profile
NID height · 21 ft21 ft tall and 305 ft long. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic embankment section and the water level is illustrative.
About Seph Mack
The primary purpose of Seph Mack is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Dcnr (state). It impounds the Tr Yellow Creek.
The dam stands 21 feet tall and stretches 305 feet across, creates a reservoir covering 2 acres, has a maximum storage capacity of 15 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1987, the structure is 39 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 02/20/2018.
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Location
| State | Pennsylvania |
| County | Indiana |
| River/Stream | Tr Yellow Creek |
| Coordinates | 40.58306, -79.04167 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 21 ft |
| Dam Height | 21 ft |
| Dam Length | 305 ft |
| Year Completed | 1987 (39 years old) |
Storage & Hydraulics
| NID Storage | 15 acre-ft |
| Max Storage | 15 acre-ft |
| Normal Storage | 9 acre-ft |
| Surface Area | 2 acres |
| Drainage Area | 0 sq mi |
Ownership & Safety
| Purpose | Recreation |
| Owner | Dcnr |
| Owner Type | State |
| Hazard Classification | Significant |
| Condition Assessment | Not assessed |
| Last Inspection | 02/20/2018 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | PA01397 |
| Federal ID | PA01397 |
| More Info | State Dam Safety Program |