Dam Report

Coal Creek Drop Dam dam

Montana, USA Coal Creek Hazard Low
Today high
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Tonight low
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Dam height
31ft
Hazard rating
Low
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Coal Creek Drop Dam -- None dam
Coal Creek Drop Dam None · Coal Creek
About this dam

Coal Creek Drop Dam

Coal Creek Drop Dam, located in Prairie, Montana, is a gravity dam primarily owned and managed by the Bureau of Land Management. Serving the purpose of flood risk reduction along Coal Creek, this structure stands at a hydraulic height of 25 feet and a structural height of 31 feet. With a total length of 2,369 feet, the dam provides a storage capacity of 98.87 acre-feet, with a normal storage level of 13.22 acre-feet and a surface area of 32.74 acres.

Despite its low hazard potential and satisfactory condition assessment, Coal Creek Drop Dam undergoes inspections every five years to ensure its continued safety and functionality. With a moderate risk rating, the dam does not currently have an emergency action plan in place, highlighting the need for ongoing risk management measures. While the dam features an uncontrolled spillway and is not state-regulated or permitted, it remains a vital asset in mitigating flood risks in the surrounding area.

As a critical infrastructure for flood control in the region, Coal Creek Drop Dam showcases the collaborative efforts of the Bureau of Land Management in designing, constructing, regulating, and inspecting the structure. With its strategic location and significant storage capacity, the dam plays a crucial role in protecting the local community and environment from potential flood events.

StateNone
River / streamCoal Creek
NID IDMT00655
Owner typeFederal
Primary purposeFlood Risk Reduction
Dam typeGravity
Dam length2,369 ft
Max storage99 AF
Normal storage13 AF
Surface area32.7 ac
Drainage area12.2 sq mi
Hazard potentialLow
ConditionSatisfactory
Last inspectionWed, 05 Sep 2018 00:00:00 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 Coal Creek Drop Dam -- inflows here typically show up in storage 24-72 hours later.

Around the water

Make a day of it

Boat launches, lakeside camping, fishing access, and other reservoirs near Coal Creek Drop Dam.

Track Coal Creek Drop Dam 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 Coal Creek Drop Dam

Where does the data for Coal Creek Drop Dam 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 Low 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.

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Snoflo-tracked reservoirs and dams within driving distance of Coal Creek Drop Dam.