Hilland Dam Reservoir Report
Nearby: Sd Noname 204 Sd Noname 258
Last Updated: December 5, 2025
Hilland Dam in South Dakota, completed in 1938, stands as a crucial water resource infrastructure along the TR CHEYENNE river.
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Summary
This private-owned Earth dam with a height of 20 feet and a length of 350 feet serves multiple purposes including flood control and water storage, with a maximum capacity of 136 acre-feet. Despite its low hazard potential, the dam is regulated, inspected, and enforced by the state regulatory agency DENR, ensuring its structural integrity and safety.
Located in Haakon County, South Dakota, Hilland Dam's risk assessment categorizes it as moderate (3), prompting the need for risk management measures. Although its condition is currently not rated, the dam's emergency action plan status and inundation maps readiness are unknown. With a spillway type of uncontrolled and a maximum discharge of 1000 cubic feet per second, the dam plays a critical role in managing water flow and protecting downstream areas. Overall, Hilland Dam stands as a vital component of the state's water resource infrastructure, warranting continued monitoring and maintenance to ensure its functionality and safety for the surrounding community and environment.
Year Completed |
1938 |
Dam Length |
350 |
Dam Height |
20 |
River Or Stream |
TR CHEYENNE |
Primary Dam Type |
Earth |
Hydraulic Height |
20 |
Nid Storage |
136 |
Hazard Potential |
Low |
Nid Height |
20 |
Seasonal Comparison
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Nearby Streamflow Levels
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.
Hilland Dam