Tom Mason Reservoir Report
Nearby: Roy Mcginnis Howard Capp
Last Updated: December 6, 2025
Tom Mason is a privately owned earth dam located in Perkins, South Dakota, along the TR-MOREAU River.
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Summary
Built in 1955 by the Natural Resources Conservation Service, this dam stands at 18 feet tall and spans 240 feet in length, with a storage capacity of 58 acre-feet. Despite its age, Tom Mason has a low hazard potential and is currently rated as "Not Rated" in terms of condition assessment.
Managed by the South Dakota Department of Environment and Natural Resources, Tom Mason is subject to state regulation, permitting, inspection, and enforcement. It serves various purposes related to water resource management, although specific details on its primary purpose are not provided. The dam is equipped with outlets and spillways, with a maximum discharge capacity of 150 cubic feet per second. While the dam's emergency action plan status and risk assessment details are not specified, its location within the St. Paul District indicates its importance for flood control and water supply in the region.
Year Completed |
1955 |
Dam Length |
240 |
Dam Height |
18 |
River Or Stream |
TR-MOREAU RIVER |
Primary Dam Type |
Earth |
Hydraulic Height |
18 |
Nid Storage |
58 |
Hazard Potential |
Low |
Nid Height |
18 |
Seasonal Comparison
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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.
Tom Mason