Lower Bear Reservoir Report

Last Updated: December 5, 2025

Lower Bear is a privately owned hydroelectric dam located in Pioneer, California, along the Bear River.


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Summary

Completed in 1952, this rockfill dam stands at a height of 245 feet and has a storage capacity of 52,025 acre-feet. The dam's primary purpose is to generate hydroelectric power, with a maximum discharge capacity of 22,210 cubic feet per second.

Managed by the Federal Energy Regulatory Commission, Lower Bear Dam is regulated by the California Department of Water Resources for safety and inspection. With a high hazard potential, the dam is classified as very high risk (1) and is subject to regular inspections to ensure its structural integrity. The dam features a controlled spillway with a width of 316 feet and is equipped with a Tainter (radial) gate for water release.

Despite its remote location in Amador County, Lower Bear Dam plays a crucial role in providing clean energy and water resource management in the region. Its presence highlights the intersection of water resources and climate considerations in sustaining hydroelectric infrastructure for the future.

Year Completed

1952

Dam Length

1844

Dam Height

245

River Or Stream

Bear River

Primary Dam Type

Rockfill

Surface Area

746

Hydraulic Height

124.9

Drainage Area

37

Nid Storage

52025

Structural Height

245

Outlet Gates

Tainter (radial) - 1

Hazard Potential

High

Nid Height

245
       
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.