Coastal Flood Warning Takes Effect Sunday in Southern California as King Tides Threaten Orange and San Diego Counties

A coastal flood warning takes effect at 5 a.m. Pacific time on Sunday for Orange and San Diego counties, as a round of king tides reaches a Southern California shoreline that has already lost sand and homes to weeks of heavy surf. The National Weather Service office in San Diego says the warning runs through 1 p.m. on Thursday, October 29, and that significant coastal flooding could reach low-lying homes, businesses and roads near the shore. Coastal flood advisories cover Los Angeles and Ventura counties over the same period.

Forecasters say tides could run 1 to 1.7 feet above predicted levels, reaching 7.5 feet or more in the mornings. The highest water is expected Monday through Wednesday, October 26 to 28. Newport Beach, which sits low along the Balboa Peninsula, says its adjusted forecasts call for peaks of 8.3 feet on Monday morning, 8.5 feet on Tuesday and 8.4 feet on Wednesday. The city says water levels have recently run 18 to 22 inches higher than expected.

Newport Beach declares a local emergency

Newport Beach has declared a local emergency and activated its emergency operations center ahead of the tides. Crews are placing sandbags, reinforcing protective sand berms and preparing pumps and tide valves in flood-prone areas. The city also plans to move about 100,000 cubic yards of sand onto eroded beaches. Parts of the Balboa Peninsula flooded earlier this month, and officials expect low-lying property to be inundated again during the morning high tides.

Why the water is running so high

The immediate cause is a king tide cycle landing on top of unusually warm ocean water. An El Nino pattern and an oceanic Kelvin wave have pushed sea levels well above the astronomical predictions that tide tables are built on. That extra water arrives after successive hurricane swells from Marie, Polo and Rachel stripped sand from beaches up and down the coast. With less sand in place, waves and tides reach houses, seawalls and roads that the beach used to protect.

The damage is already visible. Along Beach Road in Capistrano Beach, six or seven homes have been red-tagged as uninhabitable and are being demolished, according to the New York Post. Near El Moro and Crystal Cove, crews are running a 4 million dollar emergency operation to reinforce a fractured bluff about 360 feet long, using heavy equipment, rocks and sand-filled bags. In Laguna Beach, surf has pounded the oceanfront Surf and Sand resort, and local surfer Blair Conklin has documented flooded streets and collapsing bluffs in recent days.

Travel and safety effects

USA Today reported on October 23 that the high tides will disrupt travel along the Orange County coast, with Metrolink and Amtrak schedule changes during the warning period. The weather service also warns of flooding on beach parking lots, bike paths and harbor walkways, plus beach erosion and dangerous rip currents. Officials advise people to stay off flooded coastal roads and keep away from eroding bluffs.