Anderson Number 1 Reservoir Report
Nearby: J.E. Sheehan Estate #2
Last Updated: December 13, 2025
Anderson Number 1 is a privately owned dam located in Stanley, South Dakota, along the TR-North Fork of Sansare River.
°F
°F
mph
Wind
%
Humidity
Summary
Constructed in 1966 by the Natural Resources Conservation Service, this Earth-type dam stands at a height of 15 feet and has a storage capacity of 236 acre-feet. With a low hazard potential and a condition assessment of "Not Rated," Anderson Number 1 is regulated and inspected by the South Dakota Department of Environment and Natural Resources.
The dam serves no specific primary purpose and has not been modified since its completion. Despite its age, Anderson Number 1 is considered to be in satisfactory condition and poses minimal risk to surrounding areas. The dam has not been rated for emergency preparedness, and its emergency action plan and risk assessment measures remain undeveloped.
While Anderson Number 1 does not fall under the jurisdiction of the U.S. Army Corps of Engineers, it is subject to state regulations and inspections to ensure its structural integrity and safety. With its modest height and storage capacity, this dam plays a crucial role in water resource management in the region, highlighting the importance of maintaining and monitoring dams to mitigate potential risks and protect communities from flooding.
Year Completed |
1966 |
Dam Length |
800 |
Dam Height |
15 |
River Or Stream |
TR-NORTH FORK OF SANSARE |
Primary Dam Type |
Earth |
Hydraulic Height |
10 |
Nid Storage |
236 |
Hazard Potential |
Low |
Nid Height |
15 |
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.
Chisholm Number 1