Irene Reservoir Report

Last Updated: December 5, 2025

Irene is a private earth dam located in Ucross, Wyoming, along the Spring Draw river.


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Summary

Completed in 1963, this dam serves multiple purposes including fire protection, stock, and a small fish pond. With a height of 30 feet and a hydraulic height of 25 feet, Irene has a storage capacity of 40 acre-feet and a normal storage level of 21 acre-feet. The dam has a fair condition assessment and a low hazard potential, making it a relatively safe structure for water resource management.

Owned privately, Irene is regulated by the State Engineer's Office in Wyoming and undergoes regular inspections, with the last inspection conducted in June 2018. The dam has an uncontrolled spillway with a width of 20 feet and an outlet gate with a single valve. Despite its moderate risk assessment, Irene does not have an Emergency Action Plan or inundation maps prepared, highlighting potential areas for improvement in emergency preparedness. Overall, Irene is a crucial structure for water management in Johnson County, providing essential services for fire protection and livestock while maintaining a low hazard potential.

Year Completed

1963

Dam Length

240

Dam Height

30

River Or Stream

SPRING DRAW

Primary Dam Type

Earth

Surface Area

3

Hydraulic Height

25

Nid Storage

40

Structural Height

30

Outlet Gates

Valve - 1

Hazard Potential

Low

Foundations

Soil

Nid Height

30
       
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.