Mississippi River Locks and Dam 1

MISSISSIPPI· Hennepin, Minnesota· Built 1917· Concrete· 49 ft tall
Significant Hazard Navigation Recreation Federal Government

Key Takeaway

Mississippi River Locks and Dam 1 is classified as significant hazard in Minnesota. It was completed in 1917 and is 109 years old. Its primary use is navigation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 49 ft (taller than 96.1% in MN)
Dam Length742 ft
Dam TypeConcrete
Max Storage9.3K acre-ft
Normal Storage5.4K acre-ft
Surface Area900 acres
Drainage Area19,500 sq mi
Max Discharge742 cfs
Year Completed1917 (109 years old)
NID IDMN00593

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: July 13, 2021
State Regulated: No

Ownership

USACE - St. Paul District; Ford Motor Company

Federal Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Mississippi River Locks and Dam 1?

Mississippi River Locks and Dam 1 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 Mississippi River Locks and Dam 1?

Mississippi River Locks and Dam 1 is owned by USACE - St. Paul District; Ford Motor Company (Federal Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Mississippi River Locks and Dam 1 built?

Mississippi River Locks and Dam 1 was completed in 1917, making it 109 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 Mississippi River Locks and Dam 1?

Mississippi River Locks and Dam 1 serves the following purposes: Navigation, Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Mississippi River Locks and Dam 1?

Mississippi River Locks and Dam 1 has a dam height of 49 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 Mississippi River Locks and Dam 1 last inspected?

Mississippi River Locks and Dam 1 was last inspected on July 13, 2021. 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.