Dudley Dam Reservoir Report
Nearby: James Diversion Mirage
Last Updated: December 13, 2025
Dudley Dam, located in Spink, South Dakota, is a state-owned structure on the James River that was completed in 1936.
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Summary
This earth dam stands at a height of 20 feet with a hydraulic height of 20 feet as well, providing a maximum storage capacity of 200 acre-feet. The dam's primary purpose is not specified, but it serves as a regulatory structure with state jurisdiction, permitting, inspection, and enforcement by the Department of Agriculture and Natural Resources.
Despite being rated as having a low hazard potential, Dudley Dam is considered to have moderate risk with a risk assessment score of 3. The dam features an uncontrolled spillway with a width of 10 feet and no outlet gates. While the condition of the dam is currently not rated, it undergoes inspections every three years, with the last inspection conducted in October 2019. The dam does not have an Emergency Action Plan prepared as of now.
For water resource and climate enthusiasts, Dudley Dam offers a historical glimpse into South Dakota's water management infrastructure. With its notable construction year and modest storage capacity, the dam plays a role in regulating the flow of the James River. While the risk assessment indicates moderate risk, ongoing inspections and regulatory oversight aim to ensure the safety and functionality of this essential water resource structure in the region.
Year Completed |
1936 |
Dam Length |
480 |
Dam Height |
20 |
River Or Stream |
TR-JAMES RIVER |
Primary Dam Type |
Earth |
Hydraulic Height |
20 |
Nid Storage |
200 |
Outlet Gates |
None |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
20 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
James R Near Redfield Sd
|
468cfs |
James R At Huron Sd
|
548cfs |
James R At Ashton Sd
|
418cfs |
James R Near Stratford Sd
|
409cfs |
James R Near Forestburg Sd
|
560cfs |
Big Sioux R At Watertown Sd
|
26cfs |
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.
Dudley Dam