Jolly No. 1 Reservoir Report
Last Updated: December 7, 2025
Jolly No.
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Summary
1 is a privately owned earth dam located on Jolly Draw in Niobrara County, Wyoming. Completed in 1952 for irrigation purposes, this dam stands at a height of 22 feet and has a storage capacity of 60 acre-feet. Despite its low hazard potential, the dam's condition was assessed as poor in 2017, indicating a need for maintenance and repairs to ensure its continued functionality and safety.
The dam's spillway is uncontrolled with a width of 75 feet, serving as a safety feature to manage excess water during periods of high flow. While the risk assessment categorizes Jolly No. 1 as moderate, ongoing inspections and enforcement by the Wyoming State Engineer's Office help mitigate potential hazards. With Liz Cheney representing the area in Congress, the dam plays a crucial role in providing water for irrigation, fire protection, and stock use in the surrounding region.
Water resource and climate enthusiasts interested in sustainable water management and infrastructure maintenance would find Jolly No. 1 an intriguing case study. The need for regular inspections, risk assessments, and maintenance highlights the importance of proactive measures in safeguarding our water resources and infrastructure against potential risks and hazards. As climate change continues to impact water availability and usage patterns, ensuring the resilience and safety of dams like Jolly No. 1 becomes increasingly vital for the communities relying on them for water supply and agricultural needs.
Year Completed |
1952 |
Dam Length |
260 |
Dam Height |
22 |
River Or Stream |
JOLLY DRAW |
Primary Dam Type |
Earth |
Surface Area |
5 |
Hydraulic Height |
17 |
Nid Storage |
60 |
Structural Height |
25 |
Outlet Gates |
None |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
25 |
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.
Jolly No. 1