William Smith Reservoir Report
Nearby: Petersen Dam Nels (Nid)
Last Updated: December 13, 2025
William Smith is a privately owned dam located in Lyman, South Dakota, along the Cedar Creek Offstream.
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Summary
Built in 1956, this earthen dam stands at a height of 24 feet and has a storage capacity of 58 acre-feet. With a low hazard potential and a condition assessment of "Not Rated," William Smith is regulated by the South Dakota Department of Environment and Natural Resources, which oversees its permitting, inspection, and enforcement processes.
The dam, managed by the Natural Resources Conservation Service, plays a vital role in water resource management in the area, with a normal storage capacity of 47 acre-feet and a maximum discharge of 3,443 cubic feet per second. Despite its age, William Smith has not undergone any significant modifications over the years, and its emergency action plan status, hazard potential, and risk assessment remain unknown. The dam's location, at a latitude of 44.138333 and longitude of -100.12, is under the jurisdiction of the St. Paul District of the US Army Corps of Engineers, with Congressman Dusty Johnson representing the area.
As an essential part of the water infrastructure in Lyman, South Dakota, William Smith serves as a crucial asset for water supply and flood control in the region. While its condition assessment is currently "Not Rated," ongoing monitoring and maintenance ensure the safety and integrity of the dam. With its regulatory oversight by the South Dakota Department of Environment and Natural Resources, William Smith continues to play a key role in water resource management and climate resilience efforts in the area.
Year Completed |
1956 |
Dam Length |
730 |
Dam Height |
24 |
River Or Stream |
CEDARCREEK OFFSTREAM |
Primary Dam Type |
Earth |
Hydraulic Height |
24 |
Nid Storage |
58 |
Hazard Potential |
Low |
Nid Height |
24 |
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.
William Smith