Centralia Coal Mine Pond 46a Dam

Unnamed Tr - Mitchell Creek· Lewis, Washington· Built 2004· Earth·
High Hazard Flood Risk Reduction Other Public Utility

Key Takeaway

Centralia Coal Mine Pond 46a Dam is classified as high hazard in Washington. It was completed in 2004 and is 22 years old. Its primary use is flood risk reduction. 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 Length100 ft
Dam TypeEarth
Max Storage44 acre-ft
Normal Storage48 acre-ft
Surface Area3 acres
Drainage Area1 sq mi
Max Discharge621 cfs
Year Completed2004 (22 years old)
NID IDWA00687

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: August 8, 2023
State Regulated: Yes
Regulatory Agency: Washington Dept of Ecology

Ownership

TransAlta Centralia Mining LLC

Public Utility

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Centralia Coal Mine Pond 46a Dam?

Centralia Coal Mine Pond 46a Dam 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 Centralia Coal Mine Pond 46a Dam?

Centralia Coal Mine Pond 46a Dam is owned by TransAlta Centralia Mining LLC (Public Utility). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Centralia Coal Mine Pond 46a Dam built?

Centralia Coal Mine Pond 46a Dam was completed in 2004, making it 22 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 Centralia Coal Mine Pond 46a Dam?

Centralia Coal Mine Pond 46a Dam serves the following purposes: Flood Risk Reduction, Other. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

When was Centralia Coal Mine Pond 46a Dam last inspected?

Centralia Coal Mine Pond 46a Dam was last inspected on August 8, 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.