Twelve Mile Creek Watershed Site M-1

TWELVE MILE CREEK· Union, Iowa· Built 1983· Earth· 66 ft tall
High Hazard Flood Risk Reduction Recreation Water Supply Local Government

Key Takeaway

Twelve Mile Creek Watershed Site M-1 is classified as high hazard in Iowa. It was completed in 1983 and is 43 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 66 ft (taller than 99.3% in IA)
Dam Length2,100 ft
Dam TypeEarth
Max Storage27.2K acre-ft
Normal Storage10.2K acre-ft
Surface Area633 acres
Drainage Area23 sq mi
Max Discharge0 cfs
Year Completed1983 (43 years old)
NID IDIA02194

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: July 24, 2019
State Regulated: Yes
Regulatory Agency: IOWA DNR

Ownership

Creston Waterworks

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Twelve Mile Creek Watershed Site M-1?

Twelve Mile Creek Watershed Site M-1 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 Twelve Mile Creek Watershed Site M-1?

Twelve Mile Creek Watershed Site M-1 is owned by Creston Waterworks (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Twelve Mile Creek Watershed Site M-1 built?

Twelve Mile Creek Watershed Site M-1 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 Twelve Mile Creek Watershed Site M-1?

Twelve Mile Creek Watershed Site M-1 serves the following purposes: Flood Risk Reduction, Recreation, Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Twelve Mile Creek Watershed Site M-1?

Twelve Mile Creek Watershed Site M-1 has a dam height of 66 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 Twelve Mile Creek Watershed Site M-1 last inspected?

Twelve Mile Creek Watershed Site M-1 was last inspected on July 24, 2019. 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.