A storm that meteorologists warned could end up being the largest in 12 years moved into Southern California last Friday bringing 6-10 inches of rain and wind gusts up to 70 mph. Flash flood warnings were issued for all of Santa Barbara, Ventura and Los Angeles counties.
The heavy rains caused chaos on Southern California’s many busy rush-hour interstates and thoroughfares. Across the region, trees uprooted from the waterlogged ground damaged homes and obstructed motorists.
More than 20,000 Los Angeles residents were left without power on Sunday morning, while 85,623 customers were without power during the storm’s peak on Friday afternoon, according to Los Angeles Department of Water and Power officials.
In the Los Angeles suburb of Studio City, a sinkhole opened on a major street swallowing two cars. Firefighters had to rescue one of the drivers while the other managed to escape before their car fell in.
The dry Southern California ground is particularly prone to erosion, as shown by many other such incidents over the weekend. Inland at the Cajon Pass, the shoulder of Interstate 15 collapsed, sending a parked fire truck over the side. A California Department of Transportation (Caltrans) spokesperson said repairs to the damaged section of highway, which was repaved last year, could cost as much as $3 million.
In the area of Sun Valley, 20 minutes from downtown Los Angeles, 10 cars were inundated by rain runoff, prompting 15 people to be rescued by Fire Department personnel while 7 people and two dogs had to be rescued from the Sepulveda basin, a flood-control area along the Los Angeles River.
In nearby Duarte, mandatory evacuation orders were issued Friday night for areas affected by last year’s Fish Fire wildfire, which burned 4,253 acres in the San Gabriel mountains. The deforestation caused by the wildfire made the ground unstable and prone to mudslides.
Much of the damage is directly related to decades of cuts in infrastructure spending at the federal level. Last year, the US ranked 11th globally in infrastructure quality. One in every four bridges, 142,915, were classified as “deficient” by the US Department of Transportation.
Many dams and water control systems throughout Southern California date back to the 1920s and 1930s, and some are more than 100 years old.
Southern California’s 50-year-old Tex Wash Bridge on I-10, one of the main arteries connecting California and Arizona, collapsed in 2015 after heavy rains, costing millions of dollars to repair.
The storms are part of a meteorological phenomenon known as an atmospheric river, a streak of water vapor several thousand miles long. According to the National Ocean and Atmospheric Administration’s Earth System Research Laboratory, water flow in an atmospheric river can be 7.5 to 15 times that at the mouth of the Mississippi River.
The atmospheric river has moved to the Northern California area, where evacuation orders have been issued. The area is already reeling from a series of rainstorms last week. Nearly 200,000 residents near the Oroville Dam, the country’s tallest, had already been ordered to evacuate after the failure of both the main and emergency spillways.