Kolb Dam Reservoir Report
Nearby: Leola Elm Lake Dam
Last Updated: December 12, 2025
Kolb Dam, located in McPherson, South Dakota, is a privately owned earth dam constructed in 1960 by Ducks Unlimited.
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Summary
The dam, standing at a height of 9 feet and with a length of 831 feet, serves the primary purpose of water storage on Willow Creek. It has a maximum storage capacity of 248 acre-feet and a normal storage capacity of 41 acre-feet, with a drainage area of 35 square miles.
With a low hazard potential and a moderate risk assessment rating, Kolb Dam is regulated and inspected by the South Dakota Department of Environment and Natural Resources. The dam features an uncontrolled spillway with a width of 120 feet and has not been rated for its current condition. While it currently has no outlet gates, the dam plays a crucial role in managing water resources in the area and mitigating potential flood risks. Kolb Dam stands as a testament to the importance of sustainable water resource management in the face of a changing climate.
Year Completed |
1960 |
Dam Length |
831 |
Dam Height |
9 |
River Or Stream |
WILLOW CREEK |
Primary Dam Type |
Earth |
Hydraulic Height |
9 |
Drainage Area |
35 |
Nid Storage |
248 |
Outlet Gates |
None |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
9 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Elm R At Westport Sd
|
12cfs |
Foot Creek Near Aberdeen
|
0cfs |
Maple R At Nd-Sd State Line
|
5cfs |
James R At Columbia Sd
|
268cfs |
James River At Nd-Sd State Line
|
194cfs |
James R Near Stratford Sd
|
409cfs |
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.
Kolb Dam