Oja No.1 Reservoir Report
Nearby: Clanton No.1 Oja No.2
Last Updated: December 6, 2025
Oja No.1 is a privately owned dam located in Harding, South Dakota, along the TR-South Fork Grand River.
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Summary
Built in 1953, this Earth-type dam stands at a height of 25 feet and has a storage capacity of 250 acre-feet. Despite being regulated by the South Dakota Department of Environment and Natural Resources, the dam is currently rated as having a low hazard potential and its condition is not yet assessed.
Managed by the Natural Resources Conservation Service, Oja No.1 plays a crucial role in water resource management in the area, with a maximum discharge capacity of 625 cubic feet per second. Although the dam's condition is not rated, its emergency action plan status and risk assessment measures are currently not available. Despite these uncertainties, the dam continues to provide essential water storage for the surrounding community, serving as a vital infrastructure for both agricultural and environmental purposes.
With its strategic location and moderate storage capacity, Oja No.1 stands as a key component in the local water resource infrastructure. As climate change continues to impact water availability and usage patterns, monitoring and maintaining the functionality of dams like Oja No.1 will be crucial in ensuring sustainable water management practices in the region. As water resource and climate enthusiasts, understanding the role and condition of structures like Oja No.1 is essential for safeguarding our water sources for future generations.
Year Completed |
1953 |
Dam Length |
380 |
Dam Height |
25 |
River Or Stream |
TR-SOUTH FORK GRAND RIVER |
Primary Dam Type |
Earth |
Hydraulic Height |
25 |
Nid Storage |
250 |
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.
Oja No.1