Willow Glenn Reservoir Report
Nearby: Pole Creek Irrigation Miller
Last Updated: December 13, 2025
Willow Glenn is a privately owned Earth dam located in Johnson, Wyoming, along the Beaver Creek.
°F
°F
mph
Wind
%
Humidity
Summary
Completed in 1959, this dam primarily serves the purpose of irrigation, with a storage capacity of 280 acre-feet. The dam stands at a height of 30 feet, with a spillway width of 100 feet, and is classified as having a low hazard potential and fair condition assessment.
Despite its age, Willow Glenn has been maintained and inspected regularly, with the last inspection conducted in August 2018. The dam is regulated by the State of Wyoming, with permitting, inspection, and enforcement all in place to ensure its safety and functionality. In the event of an emergency, there are emergency action plans in place to mitigate any risks associated with the dam, providing a level of assurance to the surrounding community.
With its moderate risk assessment rating, Willow Glenn serves as a crucial infrastructure for the local irrigation needs in the area. As climate change continues to impact water resources, the proper maintenance and regulation of dams like Willow Glenn are essential to ensure water security and safety for the community.
Year Completed |
1959 |
Dam Length |
1250 |
Dam Height |
30 |
River Or Stream |
BEAVER CREEK |
Primary Dam Type |
Earth |
Surface Area |
19 |
Hydraulic Height |
24 |
Nid Storage |
280 |
Structural Height |
30 |
Outlet Gates |
Slide (sluice gate) - 1 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
30 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Dam Data Reference
Condition Assessment
SatisfactoryNo 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
HighDams 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.
Willow Glenn
North Fork Powder River