Oswald No. 1 Reservoir Report
Nearby: England Bros. Number 1 Jensen No.9
Last Updated: December 8, 2025
Oswald No.
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Summary
1 is a privately owned earth dam located in Mellette, South Dakota, along the tributary of Cottonwood Creek. Completed in 1968, this dam stands at a height of 25 feet with a length of 320 feet, providing a maximum storage capacity of 25 acre-feet. The dam is regulated by the South Dakota Department of Environment and Natural Resources (DENR) and is subject to state permitting, inspection, and enforcement to ensure its safety and compliance with regulations.
Despite being classified as a low hazard potential structure with a condition assessment of "Not Rated," Oswald No. 1 plays a crucial role in water resource management and climate adaptation efforts in the region. The dam serves as a vital infrastructure for flood control, water storage, and downstream water supply management. Its strategic location and design contribute to the overall resilience of the local water resources system, especially during periods of extreme weather events and changing climate patterns.
As water resource and climate enthusiasts, understanding the significance of Oswald No. 1 in the broader context of sustainable water management and climate resilience is essential. By recognizing the roles and responsibilities associated with owning, regulating, and maintaining dams like Oswald No. 1, we can contribute to the preservation and enhancement of our water resources for future generations while adapting to the challenges posed by a changing climate.
Year Completed |
1968 |
Dam Length |
320 |
Dam Height |
25 |
River Or Stream |
TRIB. COTTONWOOD CREEK |
Primary Dam Type |
Earth |
Hydraulic Height |
25 |
Nid Storage |
25 |
Hazard Potential |
Low |
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.
Oswald No. 1