Hells Canyon Dam Reservoir Report

Last Updated: December 13, 2025

Hells Canyon Dam, located in Wallowa, Oregon, on the Snake River, is a concrete structure completed in 1968 with a height of 320 feet and a capacity to store up to 200,000 acre-feet of water.


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Summary

This multipurpose dam serves various functions including fire protection, livestock, and small fish pond maintenance. With a surface area of 2412 acres and a drainage area of 73,300 square miles, Hells Canyon Dam plays a crucial role in regulating water flow and providing essential resources in the region.

Managed by a public utility, Hells Canyon Dam is state regulated and permitted by the Oregon Water Resources Department. The dam's high hazard potential and very high risk assessment underline the importance of effective risk management measures and emergency preparedness. Despite not being currently rated for condition assessment, the dam's strategic location and significant hydraulic height of 318 feet highlight its critical role in water resource management and climate resilience efforts in the area.

As a key infrastructure on the Snake River, Hells Canyon Dam's significance extends beyond its primary purposes to encompass ecosystem management, flood control, and water supply for agricultural and urban areas. With its controlled spillway and impressive storage capacity, the dam stands as a testament to human ingenuity in harnessing water resources for the benefit of communities while also highlighting the need for sustainable water management practices in the face of changing climate conditions.

Year Completed

1968

Dam Length

1000

Dam Height

320

River Or Stream

SNAKE RIVER

Primary Dam Type

Concrete

Surface Area

2412

Hydraulic Height

318

Drainage Area

73300

Nid Storage

200000

Structural Height

330

Hazard Potential

High

Nid Height

330
       
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.