Larson No. 2 Reservoir Report
Nearby: Novey No. 2 Novey No. 3
Last Updated: December 7, 2025
Larson No.
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Summary
2 is a privately-owned earth dam located in Mellette, South Dakota, on the TRIB-ROUNDUP CREEK. It was completed in 1964 and stands at a height of 29 feet, with a length of 250 feet. The dam has a storage capacity of 16 acre-feet, with a maximum discharge of 168 cubic feet per second. Despite being classified as having a low hazard potential and not currently rated for condition, Larson No. 2 is regulated, permitted, inspected, and enforced by the South Dakota Department of Environment and Natural Resources (DENR).
Water resource and climate enthusiasts will be intrigued by the location of Larson No. 2, as it serves as a vital structure in the St. Paul District managed by the U.S. Army Corps of Engineers. The dam's purpose and associated structures are not specified, but its presence on Roundup Creek highlights its importance in water management and flood control within the region. While the dam has not been assessed for condition or emergency action plan readiness, its regulation and oversight by the state ensure that it meets safety standards and operational guidelines.
Given its historical significance and essential role in water management, Larson No. 2 presents a unique opportunity for further exploration and study by water resource and climate enthusiasts. The dam's relatively low hazard potential, combined with its state jurisdiction and inspection history, make it a noteworthy structure in the landscape of South Dakota's water infrastructure. Understanding the design, function, and regulation of Larson No. 2 can provide valuable insights into the intersection of water resources, climate resilience, and dam safety in the region.
Year Completed |
1964 |
Dam Length |
250 |
Dam Height |
29 |
River Or Stream |
TRIB-ROUNDUP CREEK |
Primary Dam Type |
Earth |
Hydraulic Height |
29 |
Nid Storage |
16 |
Hazard Potential |
Low |
Nid Height |
29 |
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.
Larson No. 2