Star Lake Dam Reservoir Report
Last Updated: December 13, 2025
Star Lake Dam, located in Gregory, South Dakota, is a privately-owned earth dam constructed in 1934 on the TR-PONCA CREEK.
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Summary
With a height of 24 feet and a length of 957 feet, the dam has a storage capacity of 252 acre-feet, providing essential water resources for the surrounding area. The dam is regulated by the South Dakota Department of Agriculture and Natural Resources, ensuring it meets state inspection and enforcement standards.
Despite its low hazard potential and current "Not Rated" condition assessment, Star Lake Dam plays a crucial role in water resource management in the region. The dam's primary purpose and associated structures are not specified, but its maximum discharge capacity is recorded at 1997 cubic feet per second. The last inspection was conducted in July 2014, and emergency protocols such as an Emergency Action Plan (EAP) have not been updated or prepared, suggesting potential areas for improvement in risk management and response.
With its historical significance dating back almost a century, Star Lake Dam stands as a testament to early water infrastructure development in South Dakota. Climate and water resource enthusiasts can appreciate the dam's engineering design and the role it plays in maintaining water supply and flood control in the area. As discussions around climate change and water scarcity continue, understanding the condition and functioning of dams like Star Lake becomes increasingly important for sustainable water resource management in the region.
Year Completed |
1934 |
Dam Length |
957 |
Dam Height |
24 |
River Or Stream |
TR-PONCA CREEK |
Primary Dam Type |
Earth |
Hydraulic Height |
24 |
Nid Storage |
252 |
Hazard Potential |
Low |
Nid Height |
24 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Niobrara River At Mariaville
|
1650cfs |
Keya Paha R At Wewela Sd
|
54cfs |
Platte Creek Near Platte
|
3cfs |
Long Pine Creek Near Riverview
|
191cfs |
Keya Paha R Near Keyapaha Sd
|
33cfs |
White R Near Oacoma Sd
|
105cfs |
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.
Star Lake Dam