Centralia Coal Mine Dam No 6b

Tr-Hanaford Creek· Lewis, Washington· Built 1970· Earth·
Low Hazard Tailings Public Utility

Key Takeaway

Centralia Coal Mine Dam No 6b is classified as low hazard in Washington. It was completed in 1970 and is 56 years old. Its primary use is tailings.

Physical Details

Dam TypeEarth
Max Storage74 acre-ft
Normal Storage62 acre-ft
Surface Area15 acres
Drainage Area0 sq mi
Max Discharge69 cfs
Year Completed1970 (56 years old)
Year Modified1996
NID IDWA00290

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: 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 Dam No 6b?

Centralia Coal Mine Dam No 6b 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 Centralia Coal Mine Dam No 6b?

Centralia Coal Mine Dam No 6b 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 Dam No 6b built?

Centralia Coal Mine Dam No 6b was completed in 1970, making it 56 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 Dam No 6b?

Centralia Coal Mine Dam No 6b serves the following purposes: Tailings. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

When was Centralia Coal Mine Dam No 6b last inspected?

Centralia Coal Mine Dam No 6b 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.