Heavy Rain Brings Flooding And Risk Of Debris Flows

Heavy downpours of up to an inch of rain per hour fell in some parts of Southern California, flooding streets, and bringing the potential for mud and debris flows in areas that burned in recent years.

The National Weather Service put out flash flood warnings that an inch or more of rain could fall per hour in North Riverside County, Orange County and Southwest San Bernardino County through early Thursday evening.

A flood advisory was in effect in parts of Los Angeles County where one-quarter to one-half inch of rain was possible through Thursday evening. Around 4:30 p.m. those heavy rainfall rates were hitting hillsides near the Getty, Saddleridge, and Tick fire burn scar areas.

Heavy amounts of rain on recently-burned hillsides can release mud and debris flows that can destroy homes and roads. Los Angeles County Public Works’ mudflow forecast, however, predicted no heightened risk debris or mudslides from Thursday’s storm.

Some of the heavier rain rain was 1.6 inches falling over six hours near Interstate 10 in El Monte, and a similar amount at the Hollywood Reservoir, according to the Los Angeles County Public Works rainfall map.

Thursday’s all-day rain added to the sense of abnormality amid dozens of announcements of event cancellations and venue closures to slow the spread of the Coronavirus.

One positive note - a wave of work-at-home orders from many companies and online learning directives from colleges reduced traffic - and potential accidents - on the soaked freeways.

Areas particularly affected:

• Coachella Valley streets, which act as part of the region’s flood control system, were under water. One woman posted a photo of a car radiator deep in water in Palm Desert Thursday afternoon.
• Los Angeles County Fire Department were sent Thursday afternoon to a drainage canal in Lakewood to rescue two people trapped by rising water near Clark Ave. and E. Del Amo Blvd. One was pulled from water and the other from a precarious spot under a bridge.
• Another high water rescue of a possibly homeless person was undertaken before 5 p.m. near Lincoln Ave. and Rincon Street in Corona.
• A marine storm warning expired around 4:15 p.m., however a chance for thunderstorms remained.
• In the Inland Empire, Caltrans reported a mudflow on eastbound Highway 60 in the Badlands stretch between Moreno Valley and Beaumont. State Route 62 also flooded in Twenty-nine Palms.

Showers were expected to continue Friday and resume Monday.