Los Angeles County Flood of 2005

The Los Angeles County Flood of 2005 was the first large flood in Los Angeles County since 1938. It centered in communities near the Los Angeles River or near creeks connected to the Los Angeles River, and affected areas ranging from Santa Barbara County in the north to Orange and San Diego Counties in the south, as well as Riverside and San Bernardino Counties to the east. Large amounts of rain in the Los Angeles County area caused the Los Angeles River basin to overflow. Three people were killed. The flood caused a bridge to collapse (near Malibu, California) and major rockslides that washed away hillside houses and caused people in some areas to evacuate their homes. Although the flood was considered large, the Red Cross did not evaluate the damage it caused.

Extent and effects

Over 37 in (940 mm) of rain were recorded in downtown Los Angeles, marking the highest rainfall year since 1884. Ski areas in the San Gabriel and San Bernardino Mountains also received record amounts of snow.

Floodwaters in Atwater Village were about 1 foot high while in Malibu they reached 3.5 feet (1.1 m). In Malibu a stream crossing was washed away and in Alhambra a crossing bridge was washed away. During this flood no houses were seriously damaged, but many roads and crossings were either seriously damaged or completely destroyed.

One of the three fatalities was a truck driver who was driving down the side of a hill near Malibu when the earth underneath his heavy truck collapsed and rolled down the hill. The second was a teenager who was sitting near the river water at the Glendale Narrows near Atwater Village. He was overwhelmed by the rising water and swept away. His body was recovered about 2 miles downstream. The final fatality was a man who was walking down a creek when he too was swept away.

The floods caused the Santa Ana River to burst its banks, raising the reservoirs of Seven Oaks and Prado Dams to record levels. Further downstream, more than 3,000 people in Orange County were evacuated in anticipation of a dam failure. Through Santa Ana, the river reached its third highest peak since 1938. Prado held, but has since been the focus of a $400 million project to improve its flood-control capacity.

Large amounts of rain also fell in the Mojave Desert, causing the usually dry Mojave River to reach its terminus at Soda Lake and overflow into Silver Lake, which it has rarely reached in recorded history.