James J. Lenihan Reservoir Report

Last Updated: December 5, 2025

James J.


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Summary

Lenihan, also known as Lexington Reservoir, is a vital water resource located in Santa Clara, California. Owned by a public utility, this dam serves the primary purpose of water supply for irrigation and domestic use. Completed in 1953, this earth-type dam stands at a height of 208 feet and has a storage capacity of 21,430 acre-feet.

Situated on the Los Gatos Creek, James J. Lenihan plays a crucial role in providing water to the surrounding areas, ensuring a stable water supply for agricultural and residential needs. With a high hazard potential but a satisfactory condition assessment as of September 2017, this dam is regulated and inspected by the California Department of Water Resources (DWR) for safety and compliance.

Maintaining a close distance of 2 miles from the city of Los Gatos, this reservoir is a key component of the water infrastructure in the region. With a rich history dating back to the early 1950s, James J. Lenihan continues to be a significant asset in managing water resources and climate resilience in Santa Clara County.

Year Completed

1953

Dam Length

810

Dam Height

208

River Or Stream

Los Gatos Crk

Primary Dam Type

Earth

Surface Area

450

Hydraulic Height

188

Drainage Area

27.7

Nid Storage

21430

Hazard Potential

High

Nid Height

208
       
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.