Upper Salmon Falls Dam Reservoir Report

Last Updated: December 16, 2025

Upper Salmon Falls Dam, also known as Snake River Diversion/B-Plant (Upper) Diversion, is a private-owned concrete gravity dam located in Gooding, Idaho.


°F

°F

mph

Wind

%

Humidity

Summary

Completed in 1937 by EBASCO, this dam serves primarily for hydroelectric purposes, with a normal storage capacity of 600 acre-feet and a maximum discharge of 48,000 cubic feet per second. The dam stands at a height of 23 feet with a hydraulic height of 32.3 feet and a length of 1620 feet, controlling the flow of the Snake River.

Managed and regulated by the Federal Energy Regulatory Commission, Upper Salmon Falls Dam has a controlled spillway with a width of 730 feet and is equipped with six Tainter (radial) outlet gates. Despite its low hazard potential, the dam poses a very high risk due to its age and lack of updated condition assessment information. With a drainage area of 32,200 square miles and a surface area of 50 acres, the dam plays a crucial role in water resource management and hydroelectric power generation in the region.

Water resource and climate enthusiasts will find Upper Salmon Falls Dam to be a significant structure in the Snake River basin, providing both recreational opportunities and essential energy production. Its historical significance, coupled with its current risk management challenges, highlight the importance of ongoing monitoring and maintenance to ensure the safety and sustainability of this vital infrastructure in Idaho.

Year Completed

1937

Dam Length

1620

Dam Height

23

River Or Stream

Snake River

Primary Dam Type

Concrete

Surface Area

50

Hydraulic Height

32.3

Drainage Area

32200

Nid Storage

600

Structural Height

32.3

Outlet Gates

Tainter (radial) - 6

Hazard Potential

Low

Nid Height

32
       
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.