Loyalton (Stafford) Reservoir Report

Last Updated: December 13, 2025

Loyalton (Stafford) is a Federal-owned Earth dam located in South Dakota, specifically in Edmunds County.


°F

°F

mph

Wind

%

Humidity

Summary

The dam, designed by the Works Progress Administration (WPA) in 1934, stands at a height of 33 feet and has a length of 550 feet. It impounds the TR-N Fork Snake Creek and has a maximum storage capacity of 460 acre-feet, with a normal storage level of 214 acre-feet.

Although the dam has a low hazard potential and is currently rated as "Not Rated" in terms of its condition assessment, it is considered to have a moderate risk level. The dam features an uncontrolled spillway with a width of 3 feet, and has no outlet gates. While the dam has not been inspected since November 2010 and lacks an Emergency Action Plan (EAP) and inundation maps, it is still monitored by the St. Paul District of the US Army Corps of Engineers.

For water resource and climate enthusiasts, Loyalton (Stafford) represents a historical piece of infrastructure with important implications for flood control and water management in the region. With its unique design and operational characteristics, this dam serves as a reminder of the ongoing need for maintenance and monitoring of critical water infrastructure to ensure public safety and environmental protection.

Year Completed

1934

Dam Length

550

Dam Height

33

River Or Stream

TR-N FORK SNAKE CREEK

Primary Dam Type

Earth

Hydraulic Height

33

Drainage Area

3

Nid Storage

460

Outlet Gates

None

Hazard Potential

Low

Foundations

Soil

Nid Height

33
       
Seasonal Comparison

Weather Forecast

Dam Data Reference

Condition Assessment

Satisfactory
No 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

High
Dams 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.