James Thompson No. 1 Stock Reservoir Report
Nearby: Jolly No. 1 Dogie No. 3
Last Updated: December 6, 2025
James Thompson No.
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Summary
1 Stock, located in Edgemont, South Dakota, is a privately owned earth dam completed in 1960 with a primary purpose of fire protection, stock, or small fish pond. The dam stands at a height of 30 feet with a hydraulic height of 25 feet and a structural height of 30 feet. It has a length of 627 feet and a storage capacity of 109 acre-feet, providing essential water resources for the surrounding area.
Despite its low hazard potential, James Thompson No. 1 Stock is currently in poor condition, as assessed in April 2017. The dam has an uncontrolled spillway and one outlet gate, with a drainage area of zero. While the risk assessment indicates a moderate risk level, there is a need for further inspection and maintenance to ensure the safety and stability of the structure. As climate change continues to impact water resources, the importance of proper management and upkeep of dams like James Thompson No. 1 Stock becomes increasingly crucial.
In the Congressional District 00 of Wyoming, represented by Liz Cheney (R), this dam plays a vital role in providing water for fire protection and stock, as well as serving as a small fish pond. As water resource and climate enthusiasts, it is essential to monitor and address the maintenance needs of structures like James Thompson No. 1 Stock to ensure the sustainability of water management practices in the face of changing environmental conditions.
Year Completed |
1960 |
Dam Length |
627 |
Dam Height |
30 |
River Or Stream |
THOMPSON EAST DRAW |
Primary Dam Type |
Earth |
Surface Area |
10 |
Hydraulic Height |
25 |
Nid Storage |
109 |
Structural Height |
30 |
Outlet Gates |
Uncontrolled - 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.
James Thompson No. 1 Stock