Tailings Pond No. 4 Dam 2a Reservoir Report

Last Updated: December 13, 2025

Located in Green River, Wyoming, Tailings Pond No.


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Summary

4 Dam 2a, also known as Stevens Draw, is a private earth dam designed by Phillip B. Solseng in 1992. With a height of 27 feet and a length of 750 feet, this dam serves the primary purpose of tailings storage. The dam holds a maximum storage capacity of 4612 acre-feet and covers a surface area of 239 acres, making it a significant structure in the region.

The dam is located in Sweetwater County and is regulated by the State of Wyoming, with inspections conducted regularly to ensure its safety and compliance with state regulations. Despite being classified as having a significant hazard potential, the dam is currently assessed to be in fair condition as of the last inspection in June 2020. With a moderate risk rating of 3, the dam poses manageable risks, and no emergency action plan (EAP) is currently in place.

Tailings Pond No. 4 Dam 2a plays a crucial role in managing tailings in the area, with a controlled spillway width of 50 feet and a maximum discharge capacity of 1850 cubic feet per second. While the dam has no outlet gates, its stone core and soil foundation contribute to its structural integrity. As a key infrastructure in the region, ongoing monitoring and risk management measures will be essential to ensure the continued safety and functionality of this important water resource structure.

Year Completed

1992

Dam Length

750

Dam Height

27

River Or Stream

STEVENS DRAW

Primary Dam Type

Earth

Surface Area

239

Hydraulic Height

22

Drainage Area

4.1

Nid Storage

4612

Structural Height

39

Outlet Gates

None

Hazard Potential

Significant

Foundations

Soil

Nid Height

39
       
Seasonal Comparison

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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.