Olson No. 1 Reservoir Report
Nearby: Rada No. 2 Olson No. 2
Last Updated: December 8, 2025
Olson No.
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Summary
1, located in Mellette, South Dakota, is a privately-owned earth dam completed in 1962 with a height of 26 feet and a length of 220 feet. This dam serves as a critical structure on a tributary of the White River, with a storage capacity of 27 acre-feet and a maximum discharge of 662 cubic feet per second. Despite its low hazard potential, the dam is state-regulated by the South Dakota Department of Environment and Natural Resources (DENR), with regular inspections and enforcement measures in place to ensure its safety and integrity.
Although the dam's condition is currently rated as "Not Rated," it is reassuring to know that emergency action plans (EAP) may be in place, although details on their preparation and guidelines adherence are not available. With no associated structures and limited federal involvement, Olson No. 1 remains a local asset for water resource management, flood control, and agricultural purposes in the region. As climate change continues to impact water resources and infrastructure, the importance of maintaining and monitoring dams like Olson No. 1 becomes increasingly vital for sustainable water management and community resilience.
As water resource and climate enthusiasts, it is essential to stay informed about the status of critical infrastructure like Olson No. 1 and advocate for proactive risk management measures to ensure its longevity and safety. By promoting collaboration between private owners, state regulators, and local communities, we can work towards enhancing the resilience of dams in the face of changing environmental conditions and safeguarding water resources for future generations.
Year Completed |
1962 |
Dam Length |
220 |
Dam Height |
26 |
River Or Stream |
TRIB. WHITE RIVER |
Primary Dam Type |
Earth |
Hydraulic Height |
26 |
Nid Storage |
27 |
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.
Olson No. 1