Petranek #1 Reservoir Report
Nearby: Highway Dept. #3 Highway Dept. #2
Last Updated: December 13, 2025
Petranek #1 is a state-regulated dam located in Mellette, South Dakota, along the Little White River tributary.
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Summary
Built in 1934, this earth dam stands at 33 feet tall and spans a length of 1174 feet, with a maximum storage capacity of 376 acre-feet. The dam's primary purpose and associated structures are not specified, but it is under the jurisdiction of the South Dakota Department of Agriculture and Natural Resources (DANR).
Despite being rated as having a low hazard potential and not currently assessed for condition, Petranek #1 undergoes inspections every three years, with the last inspection conducted in September 2017. The dam is equipped with state permitting, inspection, and enforcement protocols, ensuring its functionality and safety. The area is represented in Congress by Dusty Johnson (R), and the dam falls under the oversight of the St. Paul District of the US Army Corps of Engineers, although the dam itself is not owned or funded by any federal agency.
Water resource and climate enthusiasts will find Petranek #1 an intriguing structure due to its historical significance and role in managing the waters of the Little White River tributary. As a state-regulated dam with a capacity to store significant volumes of water, it serves as a vital component in South Dakota's water management infrastructure. The data provided offers a glimpse into the technical details and operational aspects of this dam, highlighting the importance of proper regulation and maintenance to ensure its continued effectiveness in water resource management.
Year Completed |
1934 |
Dam Length |
1174 |
Dam Height |
33 |
River Or Stream |
LITTLE WHITE RIVER TRIBUTARY |
Primary Dam Type |
Earth |
Hydraulic Height |
33 |
Nid Storage |
376 |
Hazard Potential |
Low |
Nid Height |
33 |
Seasonal Comparison
Weather Forecast
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.
Petranek #1