California Prepares for Historic Coastal Flooding and Mudslides from Super El Niño

California is bracing for extensive coastal flooding, erosion, and mudslides this winter as a powerful Super El Niño is expected to bring historic sea levels and storms to the state.

The combination of elevated sea levels, intense king tides, and heavy rains threatens widespread damage to coastal communities and burn zones, according to multiple experts and officials.

Sea levels off California's coast have already risen several inches above forecasts, eroding beaches and exposing old infrastructure before El Niño reaches its peak, Los Angeles Times reports.

University of California climate scientist Daniel Swain said, "Folks who really think about coastal risks are very concerned that the single-highest sea levels on record are quite possible this winter in California. And that is going to be a problem."

Swain highlighted that the highest tides are expected to occur around Thanksgiving, Christmas Eve, and January 22, potentially coinciding with major winter storms that could cause flooding and erosion in low-lying areas like Mission Beach, Newport Beach, and parts of Long Beach.

Research geologist Jonathan Warrick with the U.S. Geological Survey explained how El Niño warms offshore waters, causing them to rise up to a foot higher than average.

"There's a phenomena during El Niños where the waters offshore California get warmer, and they actually rise up, up to a foot, sometimes more, higher than average," Warrick said.

He added that rising seas combined with heavy rainfall create drainage challenges, increasing flood risks.

Marin County officials are preparing for the flooding threat by inspecting culverts, clearing storm drains, and mapping vulnerable low-lying areas to install sandbags and deploy portable pumps as needed.

Nick Brubaker, Marin County's chief resilience officer, warned, "We know that we're going to have elevated sea levels just from the El Niño effect. We also know that we have king tides coming this fall and winter. If they coincide with a significant atmospheric river, we could see very significant flooding impacts across the county."

Brubaker also noted the importance of early warning systems, stating the county plans to send notifications up to five days before severe weather events.

San Diego County faces heightened mudslide risks in recent wildfire burn zones, as these areas lack vegetation to absorb rainfall.

Oscar Sotelo of Cal Fire said, "After a wildfire, that land no longer has protection, no vegetation. So it not only burns the land, but creates a zone for mudslides, especially now that the El Niño is coming."

He urged homeowners near burn zones to prepare by clearing drains and using sandbags to protect their properties.

"We hope that people are taking this seriously and don't be too casual about this. This El Niño has the potential to do serious damage, especially in burn areas and low-lying flash flood zones," Sotelo said.

Scientists also pointed out that this El Niño event is complicated by ongoing climate change, which has already raised sea levels by about a foot in places like San Francisco Bay, exacerbating flood risks.

Kelvin waves, slow-moving ocean waves tied to El Niño, push sea levels higher along the coasts of the Americas, further increasing flooding potential, according to CNN.

Patrick Barnard from the University of California, Santa Cruz, said the increased coastal water levels threaten an additional 170,000 people and $60 billion in property compared to a non-El Niño year.

Overall, coastal hazards are considered certain, while precipitation patterns remain less predictable across California.