Gregg Dam Reservoir Report
Nearby: Horstman #1 Carter Dam
Last Updated: December 13, 2025
Located in Todd, South Dakota, Gregg Dam is a privately owned structure that plays a crucial role in water resource management in the region.
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Summary
Completed in 2009, this earth dam stands at a height of 12 feet and has a storage capacity of 155 acre-feet. Situated on TR White Horse Creek, Gregg Dam serves as a vital infrastructure for flood control and water supply purposes.
Managed by KONECHNE ENG. and regulated by the South Dakota Department of Environment and Natural Resources (DENR), Gregg Dam has a low hazard potential with a moderate risk assessment rating. The dam features an uncontrolled spillway with a width of 100 feet, capable of handling a maximum discharge of 1350 cubic feet per second. Despite its importance, the dam's condition assessment is currently not rated, highlighting the need for regular inspections and maintenance to ensure its continued functionality.
With its strategic location and significant impact on the local water resources, Gregg Dam is a key asset in the region's resilience against climate change and water-related challenges. As water resource and climate enthusiasts continue to monitor and advocate for sustainable water management practices, Gregg Dam stands as a critical infrastructure supporting the community's water security and environmental sustainability efforts.
Year Completed |
2009 |
Dam Length |
500 |
Dam Height |
12 |
River Or Stream |
TR WHITE HORSE CREEK |
Primary Dam Type |
Earth |
Hydraulic Height |
12 |
Drainage Area |
3 |
Nid Storage |
155 |
Outlet Gates |
None |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
12 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Keya Paha R Near Keyapaha Sd
|
33cfs |
Little White R Below White River Sd
|
141cfs |
White River Near White River
|
42cfs |
Little White R Near Rosebud Sd
|
96cfs |
Niobrara River Near Sparks
|
934cfs |
Keya Paha R At Wewela Sd
|
54cfs |
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.
Gregg Dam