Flat Rock

SCHUYLKILL RIVER· Philadelphia, Pennsylvania· Built 1977· Concrete· 21 ft tall
Low Hazard Recreation State Government

Key Takeaway

Flat Rock is classified as low hazard in Pennsylvania. It was completed in 1977 and is 49 years old. Its primary use is recreation.

Physical Details

Dam Height 21 ft (taller than 46.9% in PA)
Dam Length510 ft
Dam TypeConcrete
Max Storage1.5K acre-ft
Normal Storage788 acre-ft
Surface Area105 acres
Drainage Area1,809 sq mi
Year Completed1977 (49 years old)
NID IDPA00896

Safety Information

Low Hazard

No probable loss of human life and low economic/environmental losses expected.

Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?

Emergency Action Plan: No
Last Inspection: November 9, 2017
State Regulated: Yes
Regulatory Agency: Pennsylvania Department of Environmental Protection

Ownership

DEP

State Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Flat Rock?

Flat Rock is classified as Low Hazard. No probable loss of human life and low economic/environmental losses expected. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Flat Rock?

Flat Rock is owned by DEP (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Flat Rock built?

Flat Rock was completed in 1977, making it 49 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.

What is the primary purpose of Flat Rock?

Flat Rock serves the following purposes: Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Flat Rock?

Flat Rock has a dam height of 21 ft. Dam height is measured from the natural streambed at the downstream toe to the top of the dam, and may differ from the visible height.

When was Flat Rock last inspected?

Flat Rock was last inspected on November 9, 2017. Inspection dates indicate when a formal review occurred, not the results of that inspection.

Data from the National Inventory of Dams (NID) maintained by the US Army Corps of Engineers. Dam conditions may have changed since the last update. This site is not affiliated with USACE. Do not use for emergency planning — contact your local dam safety program.