Centralia Coal Mine Pond 46 Dam

Centralia Coal Mine Pond 46 Dam is an earth dam located in Lewis County, Washington, built in 2004. It carries a High hazard potential classification and has a fair condition assessment.

About Centralia Coal Mine Pond 46 Dam

The primary purpose of Centralia Coal Mine Pond 46 Dam is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by Transalta Centralia Mining Llc (public utility). It impounds the Tr - Mitchell Creek.

The dam stands 30 feet tall and stretches 190 feet across, creates a reservoir covering 4 acres, has a maximum storage capacity of 16 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 2004, the structure is relatively new.

This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 08/27/2015. That was 10 years ago — unusually long for a high-hazard dam, which typically requires more frequent inspections.

Living Downstream

If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Washington dam safety program can provide more specific information about emergency planning for this structure.

Search for dams near your address to see all dams in your area with hazard classifications and safety data.

High HazardFair ConditionEmergency Action Plan: Yes

Location

StateWashington
CountyLewis
River/StreamTr - Mitchell Creek
Coordinates46.69592, -122.75901

Physical Characteristics

Dam TypeEarth
NID Height30 ft
Dam Length190 ft
Year Completed2004 (22 years old)

Storage & Hydraulics

NID Storage16 acre-ft
Max Storage16 acre-ft
Normal Storage7 acre-ft
Surface Area4 acres
Drainage Area0 sq mi
Max Discharge300 cfs

Ownership & Safety

PurposeFlood Risk Reduction
OwnerTransAlta Centralia Mining LLC
Owner TypePublic Utility
Hazard ClassificationHigh
Condition AssessmentFair
Last Inspection08/27/2015
Emergency Action PlanYes

Identifiers

NID IDWA00681
Federal IDWA00681
More InfoState Dam Safety Program

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