Thompson Ranch Dam Reservoir Report
Nearby: Ebersoll Dam Bockert
Last Updated: December 6, 2025
Thompson Ranch Dam in South Dakota, completed in 2003, is a private earth dam standing at 22 feet high and with a storage capacity of 78 acre-feet.
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Summary
Located in Fall River County along the TR Hay Canyon stream, this dam serves as a vital water resource for the region, with a moderate risk assessment rating of 3. With a low hazard potential and not yet rated in terms of condition assessment, the dam is regulated and inspected by the state's DENR agency.
Owned by a private entity and designed by USDA NRCS, Thompson Ranch Dam plays a crucial role in managing water flow and storage in the area. The dam's uncontrolled spillway, with a width of 80 feet, can handle a maximum discharge of 1080 cubic feet per second. Despite not having outlet gates, the dam has a normal storage capacity of 37 acre-feet and covers a drainage area of 2 square miles.
As a key infrastructure in water resource management, Thompson Ranch Dam contributes to the sustainable utilization of water for various purposes. With its strategic location and design, this dam is essential in ensuring water availability for agricultural, industrial, and environmental needs in the region. Maintaining and monitoring the dam's condition is crucial to guarantee its safety and functionality in the face of changing climate conditions.
Year Completed |
2003 |
Dam Length |
420 |
Dam Height |
22 |
River Or Stream |
TR HAY CANYON |
Primary Dam Type |
Earth |
Hydraulic Height |
22 |
Drainage Area |
2 |
Nid Storage |
78 |
Outlet Gates |
None |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
22 |
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.
Thompson Ranch Dam