Box Canyon Reservoir Report

Last Updated: December 5, 2025

Box Canyon, located in Siskiyou County, California, is a concrete gravity dam completed in 1970 for flood risk reduction along the Sacramento River.


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Summary

With a height of 220 feet and a length of 1,100 feet, this dam has a storage capacity of 26,000 acre-feet and covers a surface area of 430 acres. Managed by the local government, Box Canyon serves multiple purposes including flood risk reduction, hydroelectric power generation, and recreation.

The dam is regulated by both state and federal agencies, with inspections conducted by the Federal Energy Regulatory Commission. Its hazard potential is categorized as high, and a risk assessment has deemed it to have a moderate risk level. Despite its age, the condition assessment of Box Canyon is currently listed as "Not Available," with the last inspection date recorded in September 2020. Emergency action plans are in place, meeting guidelines and last reviewed in December 2020.

For water resource and climate enthusiasts, Box Canyon offers a fascinating example of infrastructure designed to mitigate flood risks while providing additional benefits such as renewable energy generation and recreational opportunities. As part of the Sacramento River system, this dam plays a crucial role in water management and protection in the region. Ongoing monitoring and maintenance ensure the safety and functionality of Box Canyon, highlighting the intersection of engineering, environmental stewardship, and public safety in managing water resources in California.

Year Completed

1970

Dam Length

1100

Dam Height

220

River Or Stream

Sacramento River

Primary Dam Type

Concrete

Surface Area

430

Drainage Area

126

Nid Storage

26000

Structural Height

209

Hazard Potential

High

Foundations

Rock

Nid Height

220
       
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.