Devils Gate

Devils Gate is a gravity dam located in Los Angeles County, California, built in 1920. It carries a High hazard potential classification and has a satisfactory condition assessment.

About Devils Gate

The primary purpose of Devils Gate is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by Los Angeles County Department Of Public Works (local government). It impounds the Arroyo Seco near Pasadena.

The dam stands 108 feet tall and stretches 252 feet across, creates a reservoir covering 110 acres, has a maximum storage capacity of 2,600 acre-feet, and collects water from a drainage area of 29 square miles. Completed in 1920, the structure is over a century old.

This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 09/16/2025.

At 108 feet, this dam is taller than 98% of all dams in the United States.

Living Downstream

If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The California dam safety program can provide more specific information about emergency planning for this structure.

Search for dams near your address to see all dams in your area with hazard classifications and safety data.

High HazardSatisfactory ConditionEmergency Action Plan: Yes

Location

StateCalifornia
CountyLos Angeles
Nearest CityPasadena
River/StreamArroyo Seco
Coordinates34.18520, -118.17560

Physical Characteristics

Dam TypeGravity
NID Height108 ft
Dam Height108 ft
Dam Length252 ft
Year Completed1920 (106 years old)

Storage & Hydraulics

NID Storage2,600 acre-ft
Max Storage2,600 acre-ft
Surface Area110 acres
Drainage Area29 sq mi

Ownership & Safety

PurposeFlood Risk Reduction
OwnerLos Angeles County Department Of Public Works
Owner TypeLocal Government
Hazard ClassificationHigh
Condition AssessmentSatisfactory
Last Inspection09/16/2025
Emergency Action PlanYes

Identifiers

NID IDCA00189
Federal IDCA00189
More InfoState Dam Safety Program

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