Canyon routes from the San Fernando Valley and Ventura County to Malibu, including Topanga Canyon Boulevard and Malibu Canyon Road, remain open as of Tuesday afternoon.
Caltrans crews were positioned in advance of the storm in areas known to be prone to flooding. They were staffing the area 24 hours a day, rotating in 12-hour shifts, checking drainage systems and carrying pumps in areas prone to flooding.
"Everybody was pretty much all hands on deck," said Caltrans spokesman Jim Medina.
On Monday, falling boulders blocked at least one lane of Pacific Coast Highway just north of Topanga State Beach. By Tuesday the lanes were cleared.
"I think we're doing fairly well," Medina said. "We still have to get through today and tomorrow."
In Ventura County, tourists and locals were watching massive waves break on the beach and splash up. In areas near where the river flowed into the ocean, the water appeared much muddier than usual.
Authorities are asking Southern California drivers to stay off the roads during the current storm when possible. The roads remain slick, prone to flooding and damaged by potholes.