Big Creek Dam No. 3a Reservoir Report

Last Updated: December 5, 2025

Big Creek Dam No.


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Summary

3a, also known as Huntington Lake No. 3a, is a privately owned concrete dam located in Fresno, California. Completed in 1917, this multi-arch dam stands at a height of 29 feet and has a storage capacity of 89,800 acre-feet, making it a crucial hydroelectric facility on Big Creek. With a primary purpose of hydroelectric power generation, the dam also serves recreational purposes, offering a surface area of 1,435 acres for outdoor activities.

Managed by the Federal Energy Regulatory Commission, Big Creek Dam No. 3a is subject to state regulations and inspections by the California Department of Water Resources. Despite its low hazard potential, the dam is classified as high risk due to its age and the potential implications of its failure. Emergency action plans are in place, with the most recent update in December 2020, to ensure preparedness in case of any unforeseen events. The dam's association with other structures, such as CA00434S001 and CA00434S002, highlights its interconnectedness within the water resource management system.

Overall, Big Creek Dam No. 3a stands as a historic landmark in California's water infrastructure, contributing not only to hydroelectric power generation but also to recreational opportunities in the region. With ongoing inspections and risk assessments, the dam's safety and integrity are closely monitored to prevent any potential risks to the surrounding community and environment. As a key player in the state's water resource management, this concrete marvel continues to play a vital role in shaping California's sustainable future amidst the challenges of climate change.

Year Completed

1917

Dam Length

263

Dam Height

29

River Or Stream

Big Creek

Primary Dam Type

Concrete

Surface Area

1435

Nid Storage

89800

Hazard Potential

Low

Foundations

Rock

Nid Height

29
       
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.