Gavins Point Dam Reservoir Report
Last Updated: December 13, 2025
Gavins Point Dam, located in Yankton, South Dakota, along the Missouri River, serves as a critical flood risk reduction infrastructure managed by the US Army Corps of Engineers.
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Summary
Completed in 1958, the dam plays a crucial role in protecting downstream populations and structures from catastrophic flooding. While the dam continues to reliably reduce floods, it cannot eliminate the risk of flooding entirely, especially during extreme events when the reservoir is at or near its maximum storage level. The dam's primary threats include erosion of the foundation, damage to the spillway, and powerhouse flooding, which could lead to a breach and devastating downstream flooding.
To manage the risks associated with Gavins Point Dam, the USACE Dam Safety Program implements ongoing actions such as monitoring, maintenance, and repairs, while working closely with state and local emergency management agencies to improve preparedness and public awareness of flood risks. Additionally, specific risk reduction measures have been implemented at the dam, including the installation of additional drains, enhanced monitoring instrumentation, and repairs to the spillway to improve resiliency during future flood events. Communities downstream are encouraged to stay informed about potential flood impacts and develop evacuation plans to reduce individual risks in the event of a breach or extreme flooding. For more information on water management in the Missouri River basin and the USACE Dam Safety Program, visit their official websites.
Year Completed |
1958 |
Dam Length |
8700 |
River Or Stream |
MISSOURI RIVER |
Primary Dam Type |
Earth |
Surface Area |
32000 |
Hydraulic Height |
50 |
Drainage Area |
16000 |
Nid Storage |
540000 |
Structural Height |
74 |
Hazard Potential |
High |
Foundations |
Soil |
Nid Height |
74 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
James River Nr Yankton Sd
|
752cfs |
James R Near Scotland Sd
|
706cfs |
Bazile Creek Near Niobrara
|
192cfs |
Bazile Creek At Center
|
85cfs |
Vermillion River Nr Vermillion Sd
|
33cfs |
Verdigre C Nr Verdigre
|
206cfs |
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.
Gavins Point Dam
South Shore