Upper Diversion Dam #2 Reservoir Report
Last Updated: December 19, 2025
Upper Diversion Dam #2 is a gravity dam located on the Snake River in Idaho Falls, Idaho, completed in 1982 for hydroelectric and recreational purposes.
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Summary
Owned by the local government, this dam stands at a height of 33 feet and has a length of 470 feet, with a storage capacity of 1230 acre-feet. With a low hazard potential and a controlled spillway, the dam's maximum discharge capacity is 15,000 cubic feet per second.
Managed by the Federal Energy Regulatory Commission, Upper Diversion Dam #2 is inspected every three years, with the last inspection conducted in September 2017. Despite its low hazard potential, the dam is categorized as having a very high risk due to its age and location. Emergency action plans are in place, although specific details on preparedness and risk management measures are not readily available. Overall, this dam serves as a vital resource for water diversion and energy production in the region, contributing to both economic development and environmental conservation efforts.
Year Completed |
1982 |
Dam Length |
470 |
Dam Height |
33 |
River Or Stream |
Snake River |
Primary Dam Type |
Gravity |
Surface Area |
100 |
Drainage Area |
9800 |
Nid Storage |
1230 |
Outlet Gates |
Other Controlled - 1 |
Hazard Potential |
Low |
Nid Height |
33 |
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.
Upper Diversion Dam #2