Bonesteel Lake Reservoir Report
Nearby: Logan Thoene No.1 Alford Dam
Last Updated: December 13, 2025
Bonesteel Lake, located in Gregory, South Dakota, is a state-regulated water resource with a low hazard potential.
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Summary
This Earth-type dam, completed in 1935, stands at a height of 15 feet and has a maximum storage capacity of 132 acre-feet. The lake serves as a source of water for the surrounding area, with a drainage area of 1 square mile and a maximum discharge of 1340 cubic feet per second.
Despite its age, Bonesteel Lake's condition assessment is currently labeled as "Not Rated," with the last inspection date recorded in October 2017. The dam is inspected every 3 years to ensure its structural integrity and compliance with regulatory standards set by the South Dakota Department of Agriculture and Natural Resources. While the lake itself does not have a designated primary purpose, it remains a vital resource for water supply, recreational activities, and wildlife habitat in the region.
Overall, Bonesteel Lake offers a glimpse into the intersection of water resource management and climate adaptation in South Dakota. With its historical significance, regulatory oversight, and potential for future risk assessment and management measures, this dam serves as a focal point for both water resource enthusiasts and climate advocates looking to understand the complexities of balancing water needs with environmental conservation in a changing climate.
Year Completed |
1935 |
Dam Length |
550 |
Dam Height |
15 |
River Or Stream |
PONCA CREEK OFFSTREAM |
Primary Dam Type |
Earth |
Hydraulic Height |
15 |
Drainage Area |
1 |
Nid Storage |
132 |
Hazard Potential |
Low |
Nid Height |
15 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Platte Creek Near Platte
|
3cfs |
Niobrara River At Mariaville
|
1650cfs |
Keya Paha R At Wewela Sd
|
54cfs |
Long Pine Creek Near Riverview
|
191cfs |
Ponca Creek At Verdel
|
23cfs |
Niobrara River Nr. Verdel
|
517cfs |
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.
Bonesteel Lake