Centralia Coal Mine Dam No 8a Reservoir Report
Last Updated: December 15, 2025
Centralia Coal Mine Dam No 8a, also known as Widco Dam No.
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Summary
8a, is a significant earth dam located in Lewis County, Washington. Built in 1972 for the primary purpose of tailings storage, this dam stands at a hydraulic height of 18 feet and a structural height of 15 feet. It has a maximum storage capacity of 103 acre-feet, with a normal storage level of 59 acre-feet, and covers a surface area of 13 acres.
Managed by a public utility, Centralia Coal Mine Dam No 8a is regulated by the Washington Department of Ecology and subject to state inspection and enforcement. It is situated on Tr-South Hanaford Creek in a remote area with no associated structures, making it a crucial part of the local water resource infrastructure. While the dam's condition is currently not rated, its hazard potential is deemed significant, highlighting the importance of ongoing monitoring and maintenance to ensure the safety of the surrounding community and environment.
As water resource and climate enthusiasts, understanding the details of Centralia Coal Mine Dam No 8a provides valuable insight into the management of water resources in Washington state. With its historical significance and potential impact on the local ecosystem, this dam serves as a reminder of the intricate balance between human development and environmental conservation in the face of changing climate patterns. By staying informed and advocating for sustainable water management practices, enthusiasts can contribute to the preservation of vital water resources for future generations.
Year Completed |
1972 |
River Or Stream |
Tr-South Hanaford Creek |
Primary Dam Type |
Earth |
Surface Area |
13 |
Hydraulic Height |
18 |
Drainage Area |
2.35 |
Nid Storage |
103 |
Structural Height |
15 |
Hazard Potential |
Significant |
Foundations |
Soil |
Nid Height |
18 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Dam Data Reference
Condition Assessment
SatisfactoryNo existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
Fair
No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
Poor A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency. Investigations and studies are necessary.
Unsatisfactory
A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
Not Rated
The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Not Available
Dams for which the condition assessment is restricted to approved government users.
Hazard Potential Classification
HighDams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
Significant
Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environment damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
Low
Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
Undetermined
Dams for which a downstream hazard potential has not been designated or is not provided.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.
Centralia Coal Mine Dam No 8a