Marion Reservoir Dam

LIMB BRANCH· Williamson, Illinois· Built 1971· Earth· 25 ft tall
Significant Hazard Water Supply Local Government

Key Takeaway

Marion Reservoir Dam is classified as significant hazard in Illinois. It was completed in 1971 and is 55 years old. Its primary use is water supply. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 25 ft (taller than 42.6% in IL)
Dam Length895 ft
Dam TypeEarth
Max Storage1.9K acre-ft
Normal Storage966 acre-ft
Drainage Area24 sq mi
Year Completed1971 (55 years old)
NID IDIL00014

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: No
Last Inspection: June 28, 2023
State Regulated: Yes
Regulatory Agency: IDNR

Ownership

CITY OF MARION

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Marion Reservoir Dam?

Marion Reservoir 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 Marion Reservoir Dam?

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

When was Marion Reservoir Dam built?

Marion Reservoir Dam was completed in 1971, making it 55 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 Marion Reservoir Dam?

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

How tall is Marion Reservoir Dam?

Marion Reservoir Dam has a dam height of 25 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 Marion Reservoir Dam last inspected?

Marion Reservoir Dam was last inspected on June 28, 2023. 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.