H.K. Thatcher Lock and Dam

OUACHITA· Union, Arkansas· Built 1983· Gravity·
Significant Hazard Navigation Recreation Water Supply Federal Government

Key Takeaway

H.K. Thatcher Lock and Dam is classified as significant hazard in Arkansas. It was completed in 1983 and is 43 years old. Its primary use is navigation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Length698 ft
Dam TypeGravity
Max Storage108.0K acre-ft
Normal Storage79.9K acre-ft
Surface Area12,200 acres
Drainage Area6,569 sq mi
Max Discharge250,000 cfs
Year Completed1983 (43 years old)
NID IDAR01515

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: December 18, 2015
State Regulated: No

Ownership

USACE - Vicksburg District

Federal Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of H.K. Thatcher Lock and Dam?

H.K. Thatcher Lock and 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 H.K. Thatcher Lock and Dam?

H.K. Thatcher Lock and Dam is owned by USACE - Vicksburg District (Federal Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was H.K. Thatcher Lock and Dam built?

H.K. Thatcher Lock and Dam was completed in 1983, making it 43 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 H.K. Thatcher Lock and Dam?

H.K. Thatcher Lock and Dam serves the following purposes: Navigation, Recreation, Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

When was H.K. Thatcher Lock and Dam last inspected?

H.K. Thatcher Lock and Dam was last inspected on December 18, 2015. 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.