Lake Hillsboro Dam

TRIB MIDDLE FORK SHOAL CREEK· Montgomery, Illinois· Built 1917· Earth· 34 ft tall
Significant Hazard Recreation Water Supply Local Government

Key Takeaway

Lake Hillsboro Dam is classified as significant hazard in Illinois. It was completed in 1917 and is 109 years old. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 34 ft (taller than 73.9% in IL)
Dam Length693 ft
Dam TypeEarth
Max Storage1.7K acre-ft
Normal Storage879 acre-ft
Surface Area107 acres
Drainage Area7 sq mi
Max Discharge3,276 cfs
Year Completed1917 (109 years old)
NID IDIL00699

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 Hillsboro Dam?

Lake Hillsboro 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 Hillsboro Dam?

Lake Hillsboro 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 Hillsboro Dam built?

Lake Hillsboro Dam 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 Lake Hillsboro Dam?

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

How tall is Lake Hillsboro Dam?

Lake Hillsboro Dam has a dam height of 34 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 Hillsboro Dam last inspected?

Lake Hillsboro 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.