Dam Report

Black Coulee Dam dam

Montana, USA West Branch Black Coulee Hazard Low
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Dam height
11ft
Hazard rating
Low
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Black Coulee Dam -- None dam
Black Coulee Dam None · West Branch Black Coulee
About this dam

Black Coulee Dam

Black Coulee Dam, located in Blaine, Montana, is a Federal-owned structure managed by the Department of Interior's Fish and Wildlife Service. Built in 1938, this Earth-type dam stands at a height of 11 feet and spans 1330 feet, creating a reservoir with a storage capacity of 1398 acre-feet. The primary purpose of Black Coulee Dam is to serve as a Fish and Wildlife Pond, providing essential habitat for local flora and fauna.

Despite its low hazard potential, Black Coulee Dam has been assessed as being in poor condition as of 2012, with a moderate risk level. The dam has undergone structural modifications in 1992 to ensure its continued functionality. The dam features an uncontrolled spillway, slide outlet gates, and a drainage area of 12 square miles. With a history dating back over 80 years, Black Coulee Dam remains a vital component of the local ecosystem, supporting wildlife and water resource management efforts in the region.

For water resource and climate enthusiasts, Black Coulee Dam offers a compelling case study in the intersection of infrastructure, conservation, and risk management. As a critical component of the Fish and Wildlife Service's operations, the dam demonstrates the importance of sustainable water management practices in maintaining ecosystems and supporting biodiversity. With ongoing assessments and potential maintenance needs, Black Coulee Dam serves as a reminder of the ongoing challenges and responsibilities associated with managing water resources in a changing climate.

StateNone
River / streamWest Branch Black Coulee
NID IDMT00627
Owner typeFederal
Primary purposeFish And Wildlife Pond
Dam typeEarth
Year built1938
Dam height11 ft
Dam length1,330 ft
Max storage1,398 AF
Normal storage581 AF
Surface area173.0 ac
Drainage area12.0 sq mi
Hazard potentialLow
ConditionPoor
Last inspectionTue, 25 Sep 2012 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 Black Coulee 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 Black Coulee Dam.

Track Black Coulee 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 Black Coulee Dam

Where does the data for Black Coulee 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.

More reservoirs

Other water bodies near here

Snoflo-tracked reservoirs and dams within driving distance of Black Coulee Dam.

Premium feature

Favorites and alerts are part of Snoflo Premium. Save reservoirs, set storage thresholds, and get push notifications when conditions cross.

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Manage alerts in the Snoflo app

Custom alerts are configured in the iOS app -- favorite this dam, set a threshold, and you'll get a push the moment conditions cross.

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