Southern Il Power South Fly Ash Pond Dam

TRIB LAKE OF EGYPT· Williamson, Illinois· Built 1989· Earth· 29 ft tall
Low Hazard Debris Control Public Utility

Key Takeaway

Southern Il Power South Fly Ash Pond Dam is classified as low hazard in Illinois. It was completed in 1989 and is 37 years old. Its primary use is debris control.

Physical Details

Dam Height 29 ft (taller than 58.2% in IL)
Dam Length2,100 ft
Dam TypeEarth
Max Storage165 acre-ft
Normal Storage117 acre-ft
Max Discharge91 cfs
Year Completed1989 (37 years old)
NID IDIL50100

Safety Information

Low Hazard

No probable loss of human life and low economic/environmental losses expected.

Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?

Emergency Action Plan: No
Last Inspection: September 19, 2023
State Regulated: Yes
Regulatory Agency: IDNR

Ownership

SOUTHERN ILLINOIS POWER COOPERATIVE

Public Utility

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Southern Il Power South Fly Ash Pond Dam?

Southern Il Power South Fly Ash Pond Dam is classified as Low Hazard. No probable loss of human life and low economic/environmental losses expected. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Southern Il Power South Fly Ash Pond Dam?

Southern Il Power South Fly Ash Pond Dam is owned by SOUTHERN ILLINOIS POWER COOPERATIVE (Public Utility). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Southern Il Power South Fly Ash Pond Dam built?

Southern Il Power South Fly Ash Pond Dam was completed in 1989, making it 37 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 Southern Il Power South Fly Ash Pond Dam?

Southern Il Power South Fly Ash Pond Dam serves the following purposes: Debris Control. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Southern Il Power South Fly Ash Pond Dam?

Southern Il Power South Fly Ash Pond Dam has a dam height of 29 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 Southern Il Power South Fly Ash Pond Dam last inspected?

Southern Il Power South Fly Ash Pond Dam was last inspected on September 19, 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.