O'Connell Dam Reservoir Report
Nearby: Hemmingson Irr. Dam Sd Noname 112
Last Updated: December 6, 2025
O'Connell Dam, located in Haakon County, South Dakota, is a significant private earth dam constructed in 1999 by the USDA NRCS.
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Summary
The dam stands at a height of 32 feet and has a storage capacity of 71 acre-feet, with a maximum discharge capacity of 1150 cubic feet per second. Situated on the tributary of the Bad River, the dam serves the purpose of water resource management, with a spillway width of 85 feet to regulate water flow.
Managed by the Natural Resources Conservation Service, O'Connell Dam is regulated by the South Dakota Department of Environment and Natural Resources. Despite its significant hazard potential, the dam's condition is currently not rated, with moderate risk assessment. The dam's emergency action plan status is not specified, but its risk management measures are under evaluation. With its strategic location and design, O'Connell Dam plays a crucial role in water conservation and flood control efforts in the region, making it an essential structure for water resource and climate enthusiasts to monitor.
Year Completed |
1999 |
Dam Length |
200 |
Dam Height |
32 |
River Or Stream |
TRIB. BAD RIVER |
Primary Dam Type |
Earth |
Hydraulic Height |
32 |
Drainage Area |
1 |
Nid Storage |
71 |
Hazard Potential |
Significant |
Nid Height |
32 |
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.
O'Connell Dam