Lake Glenn Shoals Dam

MIDDLE FORK OF SHOAL CREEK· Montgomery, Illinois· Built 1978· Earth· 56 ft tall
Significant Hazard Flood Risk Reduction Water Supply Local Government

Key Takeaway

Lake Glenn Shoals Dam is classified as significant hazard in Illinois. It was completed in 1978 and is 48 years old. Its primary use is flood risk reduction. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 56 ft (taller than 94.4% in IL)
Dam Length1,430 ft
Dam TypeEarth
Max Storage38.9K acre-ft
Normal Storage13.0K acre-ft
Max Discharge20,800 cfs
Year Completed1978 (48 years old)
NID IDIL00971

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: February 18, 2020
State Regulated: Yes
Regulatory Agency: IDNR

Ownership

CITY OF HILLSBORO

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Lake Glenn Shoals Dam?

Lake Glenn Shoals 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 Lake Glenn Shoals Dam?

Lake Glenn Shoals Dam is owned by CITY OF HILLSBORO (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Lake Glenn Shoals Dam built?

Lake Glenn Shoals Dam was completed in 1978, making it 48 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 Lake Glenn Shoals Dam?

Lake Glenn Shoals Dam serves the following purposes: Flood Risk Reduction, Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Lake Glenn Shoals Dam?

Lake Glenn Shoals Dam has a dam height of 56 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 Lake Glenn Shoals Dam last inspected?

Lake Glenn Shoals Dam was last inspected on February 18, 2020. 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.