Dam Report

Centralia Coal Mine Dam No 3b dam

Washington, USA Tr-Hanaford Creek Hazard Significant
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Tonight low
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Dam height
140ft
Hazard rating
Significant
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Centralia Coal Mine Dam No 3b -- None dam
Centralia Coal Mine Dam No 3b None · Tr-Hanaford Creek
About this dam

Centralia Coal Mine Dam No 3b

Centralia Coal Mine Dam No 3b, also known as Widco Dam No. 3b, is a significant earth dam located in Centralia, Washington, along Tr-Hanaford Creek. Built in 1980 for the primary purpose of tailings storage, this dam stands at a hydraulic height of 140 feet with a structural height of 140 feet, stretching 1700 feet in length. The dam has a storage capacity of 860 acre-feet, with a normal storage level of 230 acre-feet, covering a surface area of 115 acres and draining a 0.5 square mile watershed.

Managed by a public utility owner type and regulated by the Washington Dept of Ecology, Centralia Coal Mine Dam No 3b is considered to have a fair condition assessment with a significant hazard potential. The dam has a history of regular inspections, with the most recent one conducted in August 2020. Despite its fair condition, the dam has not undergone any modifications over the years, and its emergency action plan (EAP) was last revised in July 2013.

Located in Congressional District 03 of Washington, Centralia Coal Mine Dam No 3b plays a crucial role in managing tailings and protecting the surrounding environment. With its strategic position and significant storage capacity, the dam serves as a key infrastructure for water resource management in the region. Enthusiasts of water resources and climate will find Centralia Coal Mine Dam No 3b to be a fascinating case study in dam engineering, regulation, and maintenance in the Pacific Northwest.

StateNone
River / streamTr-Hanaford Creek
NID IDWA00434
Owner typePublic Utility
Primary purposeTailings
Dam typeEarth
Year built1980
Dam length1,700 ft
Max storage860 AF
Normal storage230 AF
Surface area115.0 ac
Drainage area0.5 sq mi
Hazard potentialSignificant
ConditionFair
Last inspectionThu, 27 Aug 2020 12:00:00 GMT

Dam data reference

Condition Assessment

Satisfactory
No 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.
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.
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.

Hazard Potential Classification

High
Dams 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, environmental 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.
Detailed forecast

Plan around the weather

Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column on the meteogram -- rain on the basin upstream typically lifts inflow 24-72 hours later.

Hourly detail

Next 5 days, hour by hour

Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.

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Deep dive

5-day forecast table

Every 3 hours, broken out across temperature, snow, rain, humidity, and wind. Each cell is colour-coded relative to the column min/max.

TimeConditionTemp (°F)Snow (in)Rain (in)Humidity (%)Wind (mps)Wind dir
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Long-term outlook

15-day temperature & precipitation

Daily temperatures, snow, and rain projected over the next two weeks.

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Regional inflow

Nearby streamflow gauges

USGS streamgauges around Centralia Coal Mine Dam No 3b -- inflows here typically show up in storage 24-72 hours later.

Track Centralia Coal Mine Dam No 3b in the Snoflo app

Save this dam as a favorite and get the local NOAA / yr.no forecast plus regional flow context wherever you are.

FAQ

About Centralia Coal Mine Dam No 3b

Where does the data for Centralia Coal Mine Dam No 3b come from?

Structural and regulatory data come from the U.S. Army Corps of Engineers' National Inventory of Dams (NID). Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.

How often is the report updated?

NID structural data refreshes annually as the Corps publishes updated assessments. The weather forecast refreshes throughout the day.

What does the Significant hazard rating mean?

The Corps of Engineers' hazard potential classification grades probable consequences if the dam fails: High = probable loss of human life; Significant = no probable loss of human life but possible economic loss / environmental damage; Low = no probable loss of human life, only minor economic / environmental losses. See the Dam Data Reference card above for the full definitions.

What's "% of normal"?

The current storage value compared to the historical average storage on this calendar day. 100% = right on average; values above 100% mean above-normal storage (wet year); values below mean below-normal (dry year or drought).

Can I get alerts when storage crosses a threshold?

Yes -- alerts are managed in the Snoflo iOS app. Favorite this dam, set a threshold, and you'll get a push the moment conditions cross.