Marshburn Retarding Basin

Marshburn Retarding Basin is an earth dam located in Orange County, California, built in 1998. It carries a High hazard potential classification and has a satisfactory condition assessment.

About Marshburn Retarding Basin

The primary purpose of Marshburn Retarding 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 County Of Orange (local government). It impounds the Tr Marshburn Chan near Irvine.

The dam stands 27 feet tall and stretches 2,456 feet across, creates a reservoir covering 26 acres, has a maximum storage capacity of 424 acre-feet, and collects water from a drainage area of 5 square miles. Completed in 1998, the structure is 28 years 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 09/17/2025.

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
CountyOrange
Nearest CityIrvine
River/StreamTr Marshburn Chan
Coordinates33.69410, -117.72990

Physical Characteristics

Dam TypeEarth
NID Height27 ft
Dam Height27 ft
Dam Length2,456 ft
Year Completed1998 (28 years old)

Storage & Hydraulics

NID Storage424 acre-ft
Max Storage424 acre-ft
Surface Area26 acres
Drainage Area5 sq mi

Ownership & Safety

PurposeDebris Control
OwnerCounty of Orange
Owner TypeLocal Government
Hazard ClassificationHigh
Condition AssessmentSatisfactory
Last Inspection09/17/2025
Emergency Action PlanYes

Identifiers

NID IDCA01426
Federal IDCA01426
More InfoState Dam Safety Program

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