Orange County Reservoir Reservoir Report

Last Updated: December 5, 2025

Orange County Reservoir, located in Brea, California, serves as a critical water supply source for the region.


°F

°F

mph

Wind

%

Humidity

Summary

Completed in 1941, this earth dam stands at a height of 103 feet and has a storage capacity of 217 acre-feet. The reservoir is regulated and inspected by the California Department of Water Resources (DWR) for safety compliance, with a satisfactory condition assessment as of September 2017.

With a high hazard potential, Orange County Reservoir plays a vital role in water management and flood control along the Tr Fullerton Creek. The dam's primary purpose is water supply, offering a reliable resource for the surrounding community. Despite its age, the structure has undergone regular inspections, with the most recent one conducted in August 2020 to ensure the reservoir's continued safety and functionality.

Managed by a public utility agency, Orange County Reservoir exemplifies the importance of effective water resource management in the face of climate change and increasing water demands. As a key infrastructure for the region, this reservoir highlights the need for ongoing monitoring, maintenance, and risk assessment to safeguard against potential hazards and ensure the sustainable use of water resources in Orange County.

Year Completed

1941

Dam Length

655

Dam Height

103

River Or Stream

Tr Fullerton Cr

Primary Dam Type

Earth

Surface Area

7

Hydraulic Height

100

Drainage Area

0.01

Nid Storage

217

Hazard Potential

High

Nid Height

103
       
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.