Ponderosa Reservoir Report

Last Updated: December 5, 2025

Ponderosa is a significant hydroelectric dam located in Oroville, California, along the South Fork Feather River.


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Summary

Built in 1962, this earth dam stands at a height of 157 feet and serves multiple purposes including hydroelectric power generation, irrigation, and water supply. With a normal storage capacity of 4750 acre-feet, Ponderosa plays a crucial role in water management in the region.

Operated by a public utility, Ponderosa is regulated by various state and federal agencies including the California Department of Water Resources and the Federal Energy Regulatory Commission. The dam's spillway type is controlled with a width of 97 feet, ensuring efficient water release during peak flow periods. Despite its low hazard potential, Ponderosa is categorized as having a very high risk due to its structural and environmental significance.

With a drainage area of 108.3 square miles, Ponderosa provides essential water resources for the surrounding area and supports the local ecosystem. Managed and inspected regularly, this dam continues to be a vital infrastructure for water management and renewable energy production in Butte County, California.

Year Completed

1962

Dam Length

653

Dam Height

157

River Or Stream

South Fork Feather River

Primary Dam Type

Earth

Surface Area

103

Hydraulic Height

135

Drainage Area

108.3

Nid Storage

4834

Structural Height

160

Outlet Gates

Vertical Lift - 2

Hazard Potential

Low

Foundations

Rock

Nid Height

160
       
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.