Etiwanda Debris Basin

Etiwanda Debris Basin is an earth dam located in San Bernardino County, California, built in 2008. It carries a High hazard potential classification and has a satisfactory condition assessment.

About Etiwanda Debris Basin

The primary purpose of Etiwanda Debris Basin 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 County Of San Bernardino Department Of Public Works (local government). It impounds the East Etiwanda Creek near Rancho Cucamonga.

The dam stands 51 feet tall and stretches 4,175 feet across, creates a reservoir covering 24 acres, has a maximum storage capacity of 283 acre-feet, and collects water from a drainage area of 5 square miles. Completed in 2008, the structure is relatively new.

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 03/10/2025.

At 51 feet, this dam is taller than 93% of dams nationwide.

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
CountySan Bernardino
Nearest CityRancho Cucamonga
River/StreamEast Etiwanda Creek
Coordinates34.15430, -117.51200

Physical Characteristics

Dam TypeEarth
NID Height51 ft
Dam Height51 ft
Dam Length4,175 ft
Year Completed2008 (18 years old)

Storage & Hydraulics

NID Storage283 acre-ft
Max Storage283 acre-ft
Surface Area24 acres
Drainage Area5 sq mi

Ownership & Safety

PurposeFlood Risk Reduction
OwnerCounty of San Bernardino Department of Public Works
Owner TypeLocal Government
Hazard ClassificationHigh
Condition AssessmentSatisfactory
Last Inspection03/10/2025
Emergency Action PlanYes

Identifiers

NID IDCA01495
Federal IDCA01495
More InfoState Dam Safety Program

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