High tides threaten OC beaches, prompt partial Metrolink shutdown

Potentially record-setting tides threaten significant flooding at some Orange County beaches through Thursday, NBC Los Angeles reported. Metrolink plans to suspend service on part of its Orange County Line for five days beginning Monday because of the anticipated tides.

The threat extends beyond beaches to low-lying roads, properties and shoreline infrastructure, according to NBC Los Angeles. The planned rail closure follows a September disruption near San Clemente, where waves overtopped tracks and damaged the surrounding slopes.

Morning tides are forecast to reach 7.5 to 8 feet through Thursday, according to NBC Los Angeles. Tides from Monday through Wednesday could rival San Pedro's 7.93-foot record, set Jan. 10, 2005. The cited tide records go back to 1924.

A coastal flood warning covers some Orange County beaches until 1 p.m. Thursday. Beaches in Los Angeles and Ventura counties are under a coastal flood advisory. The National Weather Service expects significant flooding at some Orange County beaches but minor coastal flooding in Los Angeles County, NBC Los Angeles reported.

Newport Beach crews have been strengthening sand berms and setting out sandbags. According to NBC Los Angeles, the city reported that Sunday's morning tide reached 8 feet — almost 2 feet higher than predicted.

Metrolink's planned suspension covers the stretch between Laguna Niguel/Mission Viejo and Oceanside. In September, waves washed over tracks near San Clemente, triggering erosion and slope damage that temporarily interrupted Metrolink, Amtrak and freight operations, according to NBC Los Angeles.

Other coastal cities are also working to protect their shorelines. Long Beach has started dredging to broaden its beach, with contractors moving more than 100,000 cubic yards of sand in recent weeks. In Malibu, crews have been putting rock barriers in place to stabilize the shoreline, NBC Los Angeles reported.

The coastal advisory period also carries a moderate risk of rip currents, according to NBC Los Angeles, adding a water-safety concern as communities prepare for the high tides.