Eaton Wash Debris Basin

Eaton Wash Debris Basin is an earth dam located in Los Angeles County, California, built in 1936. It carries a High hazard potential classification and has a satisfactory condition assessment.

Hazard potentialHighFailure would probably cost lives
ConditionSatisfactoryBest of 4 ratings
Emergency action planOn file
Last inspection09/16/2025
Height63 ft
Built193690 years ago

Dam profile

NID height · 63 ft
63 FT TEN-STORY BUILDINGMEDIAN U.S. DAM · 24 FT

63 ft tall and 1,545 ft long, taller than 95% of U.S. dams with a recorded height. Height is drawn to scale against a ten-story building, about 100 ft; the profile is a generic embankment section and the water level is illustrative.

About Eaton Wash Debris Basin

The primary purpose of Eaton Wash Debris Basin is debris control. The dam is designed to catch sediment, rocks, and debris carried by flowing water — particularly important in areas prone to mudslides or heavy erosion. The dam is owned by Los Angeles County Department of Public Works (local government). It impounds the Eaton Wash near Pasadena.

The dam stands 63 feet tall and stretches 1,545 feet across, creates a reservoir covering 54 acres, has a maximum storage capacity of 721 acre-feet, and collects water from a drainage area of 9 square miles. Completed in 1936, the structure is well-established, with more than 75 years of service.

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 63 feet, this dam is taller than 95% 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.

Location

StateCalifornia
CountyLos Angeles
Nearest CityPasadena
River/StreamEaton Wash
Coordinates34.16840, -118.09370

Physical Characteristics

Dam TypeEarth
NID Height63 ft
Dam Height63 ft
Dam Length1,545 ft
Year Completed1936 (90 years old)

Storage & Hydraulics

NID Storage721 acre-ft
Max Storage721 acre-ft
Surface Area54 acres
Drainage Area9 sq mi

Ownership & Safety

PurposeDebris Control
OwnerLos Angeles County Department of Public Works
Owner TypeLocal Government
Hazard ClassificationHigh
Condition AssessmentSatisfactory
Last Inspection09/16/2025
Emergency Action PlanYes

Identifiers

NID IDCA00201
Federal IDCA00201
More InfoState Dam Safety Program