Cuyamaca Reservoir Report

Last Updated: December 5, 2025

Cuyamaca, also known as Lake Cuyamaca, is a public utility located in San Diego, California, along Boulder Creek.


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Summary

This dam, completed in 1887, serves multiple purposes including flood risk reduction, irrigation, and water supply. With a height of 40 feet and a storage capacity of 11,740 acre-feet, Cuyamaca plays a crucial role in managing water resources in the region.

Managed by the California Department of Water Resources (DWR) for safety and regulation, Cuyamaca has a high hazard potential but is currently in satisfactory condition as of the last assessment in September 2017. The dam is inspected annually, with the most recent inspection conducted in September 2019. Despite its age, Cuyamaca continues to be a vital infrastructure for water management in the area, ensuring the safety of downstream communities and providing essential water resources for various uses.

As a key component in the flood risk reduction efforts in the region, Cuyamaca is a historic and essential structure that exemplifies the intersection of water resource management and climate resilience. With its strategic location and storage capacity, this dam remains an integral part of California's water infrastructure, highlighting the importance of maintaining and monitoring such critical assets in the face of changing climate conditions.

Year Completed

1887

Dam Length

665

Dam Height

40

River Or Stream

Boulder Creek

Primary Dam Type

Earth

Surface Area

976

Hydraulic Height

34.3

Drainage Area

12

Nid Storage

11740

Hazard Potential

High

Nid Height

40
       
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.