An emerging threat comes from a pulse of Kelvin waves that boost sea levels through the Pacific Ocean, said Michael McPhaden, a senior scientist affiliated with the University of Washington\u2019s Cooperative Institute for Climate, Ocean and Ecosystem Studies. The massive, underwater waves \u2014 which result from changing winds during El Ni\u00f1o \u2014 can intensify coastal flooding when extreme storms and high winds pound California\u2019s shoreline.<\/p>\n
The next significant wave is expected to land in California by early October, according to McPhaden. So far, Kelvin waves have boosted sea levels up to 16 inches (40 centimeters) on their trek through the Pacific, said Paul Roundy, an El Ni\u00f1o researcher and atmospheric science professor at the University at Albany.<\/p>\n
They won\u2019t be the first coastal threat California has faced since El Ni\u00f1o developed in June. For weeks, the phenomenon has been supercharging hurricanes and typhoons through the Pacific, flinging tropical winds and heavy surf toward the U.S. West Coast.<\/p>\n
In early September, remnants of storm Marie slammed the Southern California coastline and all but erased some beaches and seawalls. More than a dozen oceanfront homes were severely damaged in Orange County, with at least one marked for demolition.<\/p>\n
These early bursts of \u201csubstantial\u201d beach erosion months ahead of El Ni\u00f1o\u2019s peak \u201craise the potential for more severe coastal flooding, erosion, and infrastructure damage,\u201d said Adam Smith, a Climate Central disaster researcher. Across California, coastal erosion risk tends to rise by more than two-thirds during extreme El Ni\u00f1o events, according to Climate X.<\/p>\n
With damage already beginning to stack up, California communities and state agencies are ramping up preparations for what\u2019s anticipated to be a wild winter of storms. Gov. Gavin Newsom declared a statewide emergency on Sept. 22 that directs transportation officials to assess vulnerable infrastructure. Permitting agencies are expected to help ease the way for expedited levee repairs, channel-widening projects and protections for bridges, Newsom said in his order.<\/p>\n
City officials in Carlsbad, in north San Diego County, are attempting to shore up crumbling bluffs, while authorities in storm-hit Malibu are now planning a series of community workshops starting Sept. 29 to coach residents through the \u201cunique risks\u201d that residents face living along the coast during an El Ni\u00f1o winter.<\/p>\n
\u201cWe\u2019ve mapped it out and the worst-case scenario is not good,\u201d said Susan Due\u00f1as, Malibu\u2019s public safety director. Rock slides and \u201cmud floods\u201d through vulnerable canyons can easily cut off roads located at either end of the city, potentially leaving residents stranded after heavy rains. \u201cWe tell people to have enough food for a couple weeks,\u201d Duenas said.<\/p>\n
Infrastructure and homes near recent wildfire burn scars will be especially vulnerable, said Erik Larson, a Climate X scientist. \u201cAnytime you have wildfire, especially on slopes, you\u2019re way more at risk of landslides,\u201d Larson said. \u201cThe removal of vegetation like that is going to cause a lot more water to flow over the surface, so it increases your risk of flash floods.\u201d<\/p>\n
History offers a glimpse of what a powerful El Ni\u00f1o can bring. During the tail end of the 1997-98 event, one of the strongest on record, January and February 1998 were at the time the warmest and wettest such months on record for the contiguous U.S., according to the National Oceanic and Atmospheric Administration. California recorded what was then its wettest February.<\/p>\n
Top photo: People watch as a Pacific Ocean wave crashes over a seawall protecting homes in Long Beach, California, on Sept. 7. Photographer: Mario Tama\/Getty Images North America. Bloomberg.<\/p>\n
Copyright 2026 Bloomberg.<\/p>\n
![\"newsletter\"\/](\"https:\/\/www.newsbeep.com\/us-ca\/wp-content\/uploads\/2026\/09\/subscribe-background-580x250.jpg\")
<\/p>\n
Want to stay up to date?<\/p>\n
Get the latest insurance news
sent straight to your inbox.<\/p>\n","protected":false},"excerpt":{"rendered":"California is facing a potentially multi-billion-dollar flood threat as El Ni\u00f1o gathers strength in the Pacific Ocean. The…\n","protected":false},"author":2,"featured_media":478050,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[7,9,8,10648,644,61],"class_list":["post-478049","post","type-post","status-publish","format-standard","has-post-thumbnail","category-california","tag-california","tag-california-headlines","tag-california-news","tag-el-nino","tag-flooding","tag-storm"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/posts\/478049","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/comments?post=478049"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/posts\/478049\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/media\/478050"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/media?parent=478049"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/categories?post=478049"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/tags?post=478049"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}