Rada Roy No.1 Reservoir Report
Nearby: Stromer Herman No.1 Greene No. 1
Last Updated: December 9, 2025
Rada Roy No.1 is a privately owned dam located in Mellette, South Dakota, on a tributary of Cottonwood Creek.
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Summary
Built in 1968, this earth dam stands at a height of 26 feet and has a storage capacity of 16 acre-feet. Despite its low hazard potential and a condition assessment of "Not Rated," the dam is regulated by the South Dakota Department of Environment and Natural Resources (DENR) and undergoes regular inspections, permitting, and enforcement to ensure its safety and compliance with state regulations.
The dam, with a length of 340 feet, serves as an important water resource for the area, providing irrigation and water storage benefits. Although specific purposes for the dam are not listed, its presence highlights the importance of water management in this region. With a maximum discharge capacity of 422 cubic feet per second, the dam plays a crucial role in regulating water flow and preventing potential flooding downstream.
Managed by a private owner, Rada Roy No.1 is situated in a picturesque location in South Dakota, showcasing the intersection of water resource management and climate considerations. As water resource and climate enthusiasts, this dam serves as a fascinating case study in the careful balance between human infrastructure and natural ecosystems, highlighting the ongoing efforts to ensure the safety and sustainability of our water resources in the face of changing climate conditions.
Year Completed |
1968 |
Dam Length |
340 |
Dam Height |
26 |
River Or Stream |
TRIB. COTTONWOOD CREEK |
Primary Dam Type |
Earth |
Hydraulic Height |
26 |
Nid Storage |
16 |
Hazard Potential |
Low |
Nid Height |
26 |
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.
Rada Roy No.1