Lake Mattoon Dam

LITTLE WABASH RIVER· Shelby, Illinois· Built 1957· Earth· 46 ft tall
Significant Hazard Recreation Water Supply Local Government

Key Takeaway

Lake Mattoon Dam is classified as significant hazard in Illinois. It was completed in 1957 and is 69 years old. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 46 ft (taller than 88.9% in IL)
Dam Length2,250 ft
Dam TypeEarth
Max Storage22.6K acre-ft
Normal Storage11.8K acre-ft
Surface Area980 acres
Drainage Area57 sq mi
Max Discharge28,273 cfs
Year Completed1957 (69 years old)
NID IDIL00141

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 9, 2020
State Regulated: Yes
Regulatory Agency: IDNR

Ownership

CITY OF MATTOON

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Lake Mattoon Dam?

Lake Mattoon 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 Mattoon Dam?

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

When was Lake Mattoon Dam built?

Lake Mattoon Dam was completed in 1957, making it 69 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 Mattoon Dam?

Lake Mattoon 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 Mattoon Dam?

Lake Mattoon Dam has a dam height of 46 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 Mattoon Dam last inspected?

Lake Mattoon Dam was last inspected on July 9, 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.