Yarnell Debris Basin

Yarnell Debris Basin is an earth dam located in Los Angeles County, California, built in 1963. It carries a Low hazard potential classification and has a satisfactory condition assessment.

About Yarnell Debris Basin

The primary purpose of Yarnell 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 City Of Los Angeles Department Of Water And Power (local government). It impounds the Tr Bull Canyon.

The dam stands 42 feet tall and stretches 1,290 feet across, creates a reservoir covering 10 acres, has a maximum storage capacity of 77 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1963, the structure is well into its service life at over 50 years old.

This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. The most recent inspection on record was 11/17/2025.

At 42 feet, this dam is taller than 89% of dams nationwide.

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Low HazardSatisfactory ConditionEmergency Action Plan: No

Location

StateCalifornia
CountyLos Angeles
River/StreamTr Bull Canyon
Coordinates34.30550, -118.48630

Physical Characteristics

Dam TypeEarth
NID Height42 ft
Dam Height42 ft
Dam Length1,290 ft
Year Completed1963 (63 years old)

Storage & Hydraulics

NID Storage77 acre-ft
Max Storage77 acre-ft
Surface Area10 acres
Drainage Area1 sq mi

Ownership & Safety

PurposeDebris Control
OwnerCity of Los Angeles Department of Water and Power
Owner TypeLocal Government
Hazard ClassificationLow
Condition AssessmentSatisfactory
Last Inspection11/17/2025
Emergency Action PlanNo

Identifiers

NID IDCA00099
Federal IDCA00099
More InfoState Dam Safety Program

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