Almaden Reservoir Report

Last Updated: December 5, 2025

Almaden Reservoir, located in Santa Clara County, California, serves as a crucial infrastructure for flood risk reduction in the region.


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Summary

Built in 1936, this earth dam stands at a height of 110 feet and has a storage capacity of 2000 acre-feet. Situated along Alamitos Creek, the reservoir covers an area of 62 acres and plays a vital role in irrigation and water supply for the city of San Jose.

Managed by a public utility, Almaden Reservoir is regulated by the Department of Water Resources and the Safety of Dams agency in California. With a high hazard potential but fair condition assessment, the dam undergoes regular inspections to ensure its structural integrity and operational efficiency. The last inspection conducted in December 2020 revealed that the dam meets safety standards, with an emergency action plan in place to address any potential risks or incidents.

The presence of Almaden Reservoir not only contributes to the management of flood risks but also supports the irrigation and water supply needs of the local community. As a key component of the water resource infrastructure in the area, this dam serves as a testament to the importance of sustainable water management practices in the face of climate change challenges.

Year Completed

1936

Dam Length

500

Dam Height

110

River Or Stream

Alamitos Creek

Primary Dam Type

Earth

Surface Area

62

Hydraulic Height

102

Drainage Area

12.5

Nid Storage

2000

Hazard Potential

High

Nid Height

110
       
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.