LaGrange Lock and Dam

ILLINOIS RIVER· Brown, Illinois· Built 1939· Concrete·
Significant Hazard Navigation Federal Government

Key Takeaway

LaGrange Lock and Dam is classified as significant hazard in Illinois. It was completed in 1939 and is 87 years old. Its primary use is navigation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Length676 ft
Dam TypeConcrete
Max Storage55.0K acre-ft
Normal Storage0 acre-ft
Surface Area0 acres
Drainage Area25,648 sq mi
Max Discharge156,000 cfs
Year Completed1939 (87 years old)
NID IDIL01015

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 7, 2022
State Regulated: Yes

Ownership

USACE - Rock Island District

Federal Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of LaGrange Lock and Dam?

LaGrange 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 LaGrange Lock and Dam?

LaGrange Lock and Dam is owned by USACE - Rock Island District (Federal Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was LaGrange Lock and Dam built?

LaGrange Lock and Dam was completed in 1939, making it 87 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 LaGrange Lock and Dam?

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

When was LaGrange Lock and Dam last inspected?

LaGrange Lock and Dam was last inspected on July 7, 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.