Elmer J. Chesbro Reservoir Report

Last Updated: December 5, 2025

Elmer J.


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Summary

Chesbro, also known as Chesbro Reservoir, is a vital water resource located in Morgan Hill, California. Managed by a Public Utility, this reservoir plays a crucial role in flood risk reduction, irrigation, and water supply in the region. Built in 1955, this earth dam stands at a height of 95 feet and has a storage capacity of 8086 acre-feet, serving as a lifeline for the surrounding areas.

Situated on Llagas Creek in Santa Clara County, Elmer J. Chesbro is regulated by the California Department of Water Resources and undergoes regular inspections to ensure its structural integrity. With a surface area of 328 acres and a drainage area of 19.5 square miles, this reservoir has a high hazard potential but is currently assessed to be in satisfactory condition. Its strategic location and efficient management make it a key asset in the region's water management infrastructure.

Despite its age, Elmer J. Chesbro continues to meet the water needs of the community while mitigating flood risks along the Llagas Creek. With its historical significance and ongoing maintenance efforts, this reservoir stands as a testament to effective water resource management in the face of changing climate patterns. Enthusiasts of water resources and climate resilience can appreciate the vital role that Elmer J. Chesbro plays in ensuring water security and environmental protection in the region.

Year Completed

1955

Dam Length

690

Dam Height

95

River Or Stream

Llagas Creek

Primary Dam Type

Earth

Surface Area

328

Hydraulic Height

85

Drainage Area

19.5

Nid Storage

8086

Hazard Potential

High

Nid Height

95
       
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.