Gwenmil Lake Dam

TR TO ISUM CREEK· Jefferson, Missouri· Built 1957· Earth· 29 ft tall
High Hazard Recreation Private

Key Takeaway

Gwenmil Lake Dam is classified as high hazard in Missouri. It was completed in 1957 and is 69 years old. Its primary use is recreation. 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 29 ft (taller than 59.6% in MO)
Dam TypeEarth
Max Storage47 acre-ft
Normal Storage23 acre-ft
Surface Area3 acres
Drainage Area16 sq mi
Year Completed1957 (69 years old)
NID IDMO31210

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: No
Last Inspection: November 7, 1980
State Regulated: No

Ownership

GWEN MILL LAKE SUBD INC

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Gwenmil Lake Dam?

Gwenmil Lake Dam 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 Gwenmil Lake Dam?

Gwenmil Lake Dam is owned by GWEN MILL LAKE SUBD INC (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Gwenmil Lake Dam built?

Gwenmil Lake Dam was completed in 1957, making it 69 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 Gwenmil Lake Dam?

Gwenmil 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 Gwenmil Lake Dam?

Gwenmil Lake Dam has a dam height of 29 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 Gwenmil Lake Dam last inspected?

Gwenmil Lake Dam was last inspected on November 7, 1980. 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.