Storms cause millions of dollars in damage to California highways

Recent debris flows and flooding in the San Jacinto and San Bernardino mountains have caused extensive damage to Southern California roadways, requiring some highways to be closed for months as crews work on repairs that will cost at least $14 million.

Last week’s series of storms, including a moisture-packed atmospheric river that slammed the state, has brought consistent rainfall to California, dumping 18 trillion gallons of rain — nearly half the volume of Lake Tahoe.

In between showers, road crews have been assessing the damage caused by all that water and how much it’ll cost to repair the state’s highways and byways.

One of the most damaged areas is Highway 243 in Riverside County, where a large hole formed underneath the road after heavy rains eroded the soil. As the rain poured down, the hole made way for a fast-flowing waterfall. The highway will be closed between the 10 Freeway and the city of Idyllwild for at least two months, according to a Caltrans news release.

Meanwhile, Highway 74 in Lake Hemet will be closed from Valle Vista at Borco to Mountain Center for at least a month. Combined, Caltrans estimates repairs to both highways will cost $8 million.

In Big Bear Lake, Highway 18 between Green Valley Lake Road and Big Bear Dam will be closed for two weeks “due to road loss,” Caltrans said. The estimated cost of repairs there is $2.5 million.

In the Coachella Valley, the southbound lane of the 111 Freeway will be closed for at least a month, also because of “road loss.” Caltrans said road work there will cost $3.5 million.

The amount of rain that has recently pounded the region has been too much for many of the state’s roads to withstand, Caltrans spokeswoman Terri Kasinga said Tuesday. All of the closures in San Bernardino and Riverside counties were caused by erosion that destroyed portions of the roadways, she said.

“There was so much water that it eroded over and under the pavement … and it collapsed,” she said. “The storm was just large.”

Recent storms have also made for snowy and icy conditions, forcing officials to close some highways for safety reasons.

Hundreds of drivers were stranded in the Grapevine when a powerful snowstorm closed Interstate 5 for several hours Sunday.

A new storm moving in Thursday is expected to drop snow elevations again, likely triggering another closure there.

Snowy conditions have also closed the Angeles Crest Highway between Kratka Ridge and Big Pines, Caltrans said. Elsewhere on the 2 Freeway, a large rockslide led to a separate closure between Mt. Wilson Road and Upper Big Tujunga Canyon Road. Road crews say both areas are closed until further notice.

alejandra.reyesvelarde@latimes.com

Twitter: @r_valejandra