No. 4 Reservoir Report
Nearby: No. 5a Pond No. 3
Last Updated: December 15, 2025
No.
°F
°F
mph
Wind
%
Humidity
Summary
4, also known as the Allied No. 4 Tailings Pond, is a private-owned structure located in Sweetwater County, Wyoming. Built in 1973 by designer George C. Toland, this earth dam stands at a height of 25 feet and serves the primary purpose of debris control along the Allied Draw river. With a storage capacity of 1356 acre-feet and a surface area of 175 acres, No. 4 plays a crucial role in managing water resources in the area.
Despite being classified as having a low hazard potential and a fair condition assessment, No. 4 is regulated by the State of Wyoming and undergoes regular inspections, with the last one conducted in November 2019. The dam features an uncontrolled spillway with a width of 60 feet, ensuring proper water discharge during peak flow events. While the risk assessment for No. 4 is moderate, the structure meets state guidelines for emergency action plans and risk management measures.
For water resource and climate enthusiasts, No. 4 presents an intriguing case study of a privately-owned earth dam that plays a vital role in debris control and water management in the region. With its historical significance and ongoing regulatory oversight, this structure exemplifies the intersection of infrastructure, environmental stewardship, and risk management in the context of water resource management.
Year Completed |
1973 |
Dam Length |
1500 |
Dam Height |
25 |
River Or Stream |
ALLIED DRAW |
Primary Dam Type |
Earth |
Surface Area |
175 |
Hydraulic Height |
23 |
Nid Storage |
1356 |
Structural Height |
25 |
Outlet Gates |
None |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
25 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Blacks Fork Near Little America
|
14cfs |
Green River Near Green River
|
870cfs |
Green River Below Fontenelle Reservoir
|
852cfs |
Henrys Fork Near Manila
|
49cfs |
Pacific Creek Near Farson
|
3cfs |
Green River Near La Barge
|
681cfs |
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.
No. 4