Naylors Run

NAYLORS RUN· Delaware, Pennsylvania· Built 1975· Rockfill· 13 ft tall

High Hazard Flood Risk Reduction Local Government

Key Takeaway

Naylors Run is classified as high hazard in Pennsylvania. It was completed in 1975 and is 51 years old. Its primary use is flood risk reduction. High hazard means loss of life is likely if the dam fails — it does not indicate the dam's current condition. Learn more.

Physical Details

Dam Height	13 ft (taller than 21.2% in PA)
Dam Length	302 ft
Dam Type	Rockfill
Max Storage	22 acre-ft

Drainage Area	4 sq mi
Year Completed	1975 (51 years old)
NID ID	PA00950

Safety Information

High Hazard

Loss of human life is likely if the dam fails.

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

Emergency Action Plan: Yes

Last Inspection: November 25, 2020

State Regulated: Yes

Regulatory Agency: Pennsylvania Department of Environmental Protection

Ownership

COMMISSONERS OF UPPER DARBY TOWNSHIP

Local Government

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Ridley Park Lake

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Frequently Asked Questions

What is the hazard classification of Naylors Run?

Naylors Run is classified as High Hazard. Loss of human life is likely if the dam fails. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Naylors Run?

Naylors Run is owned by COMMISSONERS OF UPPER DARBY TOWNSHIP (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Naylors Run built?

Naylors Run was completed in 1975, making it 51 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 Naylors Run?

Naylors Run serves the following purposes: Flood Risk Reduction. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Naylors Run?

Naylors Run has a dam height of 13 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 Naylors Run last inspected?

Naylors Run was last inspected on November 25, 2020. 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.