Astleford No.3 Reservoir Report
Nearby: Krogman Louie No.3 Krogman No.5
Last Updated: December 8, 2025
Astleford No.3 is a privately owned dam located in Mellette, South Dakota, along the TR Little White Offstream.
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Summary
Built in 1936, this earth dam stands at 25 feet in height, with a length of 469 feet and a storage capacity of 20 acre-feet. Although not rated for condition assessment, the dam is considered to have low hazard potential.
Managed by the South Dakota Department of Environment and Natural Resources (DENR), Astleford No.3 is subject to state regulations, permitting, inspection, and enforcement. The dam is under state jurisdiction and is regularly monitored for compliance with safety standards. Despite lacking an Emergency Action Plan (EAP) and updated contact information, the dam has not been deemed to pose significant risks.
Water resource and climate enthusiasts interested in the infrastructure of Astleford No.3 may find its historical significance and operational details intriguing. With a focus on public safety and environmental protection, the state-regulated dam plays a vital role in water management in the region. As a low-hazard structure, it serves as a testament to the importance of maintaining and monitoring dams for long-term sustainability and resilience in the face of changing climate conditions.
Year Completed |
1936 |
Dam Length |
469 |
Dam Height |
25 |
River Or Stream |
TR LITTLE WHITE OFFSTREAM |
Primary Dam Type |
Earth |
Hydraulic Height |
25 |
Nid Storage |
20 |
Hazard Potential |
Low |
Nid Height |
25 |
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.
Astleford No.3