Dynegy/Havana Sta/East Ash Pond System

TRIB ILLINOIS RIVER· Mason, Illinois· Built 1999· Earth· 38 ft tall
High Hazard Other Public Utility

Key Takeaway

Dynegy/Havana Sta/East Ash Pond System is classified as high hazard in Illinois. It was completed in 1999 and is 27 years old. Its primary use is other. High hazard means loss of life is likely if the dam fails — it does not indicate the dam's current condition. Learn more.

Physical Details

Dam Height 38 ft (taller than 80.7% in IL)
Dam Length3,800 ft
Dam TypeEarth
Max Storage622 acre-ft
Normal Storage0 acre-ft
Surface Area18 acres
Drainage Area0 sq mi
Max Discharge244 cfs
Year Completed1999 (27 years old)
NID IDIL50420

Safety Information

High Hazard

Loss of human life is likely if the dam fails.

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

Emergency Action Plan: Yes
Last Inspection: November 10, 2020
State Regulated: Yes
Regulatory Agency: IDNR

Ownership

DYNEGY MIDWEST GENERATION, LLC

Public Utility

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Dynegy/Havana Sta/East Ash Pond System?

Dynegy/Havana Sta/East Ash Pond System is classified as High Hazard. Loss of human life is likely if the dam fails. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Dynegy/Havana Sta/East Ash Pond System?

Dynegy/Havana Sta/East Ash Pond System is owned by DYNEGY MIDWEST GENERATION, LLC (Public Utility). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Dynegy/Havana Sta/East Ash Pond System built?

Dynegy/Havana Sta/East Ash Pond System was completed in 1999, making it 27 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 Dynegy/Havana Sta/East Ash Pond System?

Dynegy/Havana Sta/East Ash Pond System serves the following purposes: Other. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Dynegy/Havana Sta/East Ash Pond System?

Dynegy/Havana Sta/East Ash Pond System has a dam height of 38 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 Dynegy/Havana Sta/East Ash Pond System last inspected?

Dynegy/Havana Sta/East Ash Pond System was last inspected on November 10, 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.