North Twin Lake Dam

Moore Creek· Fairfax, Virginia· Earth· 26 ft tall
Significant Hazard Recreation Local Government

Key Takeaway

North Twin Lake Dam is classified as significant hazard in Virginia. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 26 ft (taller than 51.6% in VA)
Dam Length340 ft
Dam TypeEarth
Max Storage164 acre-ft
Normal Storage60 acre-ft
Surface Area9 acres
Drainage Area1 sq mi
NID IDVA059012

Safety Information

Significant Hazard

No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities.

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

Emergency Action Plan: Yes
Last Inspection: April 28, 2022
State Regulated: Yes
Regulatory Agency: Department of Conservation and Recreation

Ownership

Fairfax County Park Authority;Fairfax County Park Authority

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of North Twin Lake Dam?

North Twin Lake Dam is classified as Significant Hazard. No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates North Twin Lake Dam?

North Twin Lake Dam is owned by Fairfax County Park Authority;Fairfax County Park Authority (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

What is the primary purpose of North Twin Lake Dam?

North Twin Lake Dam 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 North Twin Lake Dam?

North Twin Lake Dam has a dam height of 26 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 North Twin Lake Dam last inspected?

North Twin Lake Dam was last inspected on April 28, 2022. 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.