Ortman Dam Reservoir Report
Nearby: Cooper Dam Wieman Dam
Last Updated: December 13, 2025
Ortman Dam, located in South Dakota, was completed in 2001 by the USDA NRCS and stands at a height of 22 feet along the TR.
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Summary
W. Fork Vermillion River. This earth dam has a storage capacity of 145 acre-feet and serves a low hazard potential with a moderate risk assessment rating. The dam's spillway, which is uncontrolled, has a width of 150 feet and can handle a maximum discharge of 2025 cubic feet per second.
Owned privately, Ortman Dam is regulated and permitted by the South Dakota Department of Environment and Natural Resources, with regular inspections and enforcement to ensure its safety and compliance. The dam's purpose and primary dam type are not specified, but it serves the region by providing flood control and water storage for the surrounding area. Despite its moderate risk assessment, Ortman Dam has not been rated for its condition, but its operations are carried out by the Natural Resources Conservation Service, ensuring its continued functionality and safety for the community.
Year Completed |
2001 |
Dam Length |
375 |
Dam Height |
22 |
River Or Stream |
TR. W. FORK VERMILLION RIVER |
Primary Dam Type |
Earth |
Hydraulic Height |
22 |
Drainage Area |
6 |
Nid Storage |
145 |
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.
Ortman Dam