Johnson Bros. Reservoir Report
Nearby: Pearl Ross Dell Oliver
Last Updated: December 6, 2025
Johnson Bros.
°F
°F
mph
Wind
%
Humidity
Summary
is a privately owned dam located in Perkins, South Dakota, along the TR South Grand River. Constructed in 1951 by the Natural Resources Conservation Service, this earthen dam stands at 28 feet tall and has a storage capacity of 59 acre-feet. Despite its low hazard potential, the dam is regulated by the South Dakota Department of Environment and Natural Resources, and undergoes regular inspections and maintenance to ensure its safety and functionality.
Managed by private owners, Johnson Bros. serves as an important water resource for the surrounding area, providing essential storage and flood control benefits. With a maximum discharge capacity of 125 cubic feet per second, the dam plays a crucial role in managing water flow and protecting downstream communities from potential flooding events. Additionally, its normal storage capacity of 42 acre-feet helps to support agricultural activities and maintain water supply for various uses.
Although Johnson Bros. has not been formally rated for its condition, its low hazard potential and consistent regulatory oversight suggest that it is well-maintained and properly managed. With a focus on safety and compliance, the dam continues to fulfill its primary purpose of water storage and flood mitigation, contributing to the overall resilience of the local water infrastructure in South Dakota.
Year Completed |
1951 |
Dam Length |
260 |
Dam Height |
28 |
River Or Stream |
TR SOUTH GRAND RIVER |
Primary Dam Type |
Earth |
Hydraulic Height |
28 |
Nid Storage |
59 |
Hazard Potential |
Low |
Nid Height |
28 |
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.
Johnson Bros.