High surf is wearing away parts of California's Pacific Coast Highway as a strong El Niño brings warm, rough seas, SFGate and ABC7 reported. The state transportation agency, Caltrans, is working to protect the road before winter storms arrive, the two news groups reported.

The waves come from a mix of warm water from the growing El Niño, an undersea wave of warm water and the remains of Hurricane Rachel, SFGate reported. Summer waves had already washed away sand along the coast, SFGate reported.

In Laguna Beach, Caltrans closed part of the right southbound lane after a large crack was found in the cliff next to the road, SFGate reported. Farther south, Carlsbad declared a local emergency after waves almost wiped out the road and parking lot at Tamarack State Beach, SFGate reported.

In Malibu, Caltrans crews worked on Monday to shore up the highway near Thornhill Broome Beach, ABC7 reported. The lane on the beach side was closed as seawater soaked the road, ABC7 reported. Crews are placing mesh on the ocean side and laying large boulders on top to protect the highway, a Caltrans spokesperson said, according to ABC7.

The agency has also made drains and culverts bigger along the highway after the Palisades Fire, ABC7 reported. Drivers are asked to slow down near the work, ABC7 reported. People who want to watch the big waves should park in a safe place and stay off the rocks, ABC7 reported.

Westward Beach Road, which leads to Point Dume State Beach in Malibu, has been closed since early August because of erosion, SFGate reported, citing the county beaches department. Things could get worse this winter as the sea reaches farther inland, SFGate reported.

What we know: High surf has damaged parts of the Pacific Coast Highway, and Caltrans is closing lanes and adding rock to protect it.
What we don't: When the damaged sections will be fully repaired, and how much worse the winter storms will make the erosion.