Santiago Creek Res (Irvine Lake) Reservoir Report

Last Updated: January 2, 2026

Santiago Creek Reservoir, also known as Irvine Lake, is a man-made reservoir located in Orange County, California.


°F

°F

mph

Wind

%

Humidity

Summary

It was created in 1931 by the construction of Santiago Dam, which is the primary surface flow provider for the reservoir. The dam also provides flood control and hydroelectric power. The reservoir is also fed by snowpack from the nearby Santa Ana Mountains.

The lake has a capacity of 25,000 acre-feet and is used for a variety of recreational activities such as fishing, boating, and camping. It also serves as a source of agricultural irrigation for nearby farmland. In recent years, the lake has experienced low water levels due to drought conditions and has been temporarily closed to the public. However, efforts are being made to restore the lake and improve its water quality, and it is expected to reopen for recreational use in the near future.

Reservoir Details

24hr Change None%
Percent of Normal None%
Minimum
Maximum
Average
Nid_Height 136
Hydraulic_Height 120
Primary_Dam_Type Earth
Drainage_Area 63.1
Year_Completed 1933
Dam_Height 136
River_Or_Stream Santiago Creek
Surface_Area 650
Hazard_Potential High
Nid_Storage 25000
Dam_Length 1425
       
Seasonal Comparison
Storage Levels
Pool Elevation Levels
Top Conserv Storage Levels
Inflow Levels

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.