Big Chief Dam Reservoir Report

Last Updated: December 13, 2025

Located in Natrona, Wyoming, Big Chief Dam was completed in 1964 by the Bureau of Land Management for the primary purpose of debris control along the Trib Three Buttes Creek.


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Summary

Standing at a structural height of 32 feet with a hydraulic height of 27 feet, this gravity dam made of buttress and stone materials serves as a vital structure in the region. With a storage capacity of 71.8 acre-feet and a surface area of 6.3 acres, the dam plays a crucial role in managing water resources and protecting the surrounding environment.

Despite being classified as having a low hazard potential, Big Chief Dam's condition assessment is deemed unsatisfactory, highlighting the need for ongoing maintenance and monitoring. The dam features an uncontrolled spillway and no outlet gates, posing challenges in the event of emergencies. With Liz Cheney representing the area in Congress, it is essential for stakeholders to work together to ensure the safety and functionality of this critical infrastructure. As water resource and climate enthusiasts, it is important to stay informed and engaged in efforts to safeguard Big Chief Dam and other vital structures for the benefit of the community and the environment.

Year Completed

1964

Dam Length

413

River Or Stream

TRIB THREE BUTTES CREEK

Primary Dam Type

Gravity

Surface Area

6.3

Hydraulic Height

27

Nid Storage

71.8

Structural Height

32

Outlet Gates

None

Hazard Potential

Low

Foundations

Unlisted/Unknown

Nid Height

32
       
Seasonal Comparison

Weather Forecast

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. 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

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, 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.