California Governor Gavin Newsom declared a statewide emergency on September 22 after climate models indicated that the strengthening El Nino could inflict $2‑3 billion in flood damage across the state this winter.
The forecast, produced by Climate X, a Google‑Ventures‑backed risk firm, relies on data from past El Nino events that have cost the state roughly $500 million per year in flood losses. The agency estimates that the current anomaly could amplify those figures by 400 percent.
Senior scientist Michael McPhaden of the University of Washington’s Cooperative Institute warned that a pulse of Kelvin waves is expected to raise sea levels by up to 16 inches (40 cm) along the coast by early October, intensifying the impact of atmospheric rivers such as the Pineapple Express.
In the weeks before the peak, remnants of Storm Marie already eroded dozens of miles of shoreline, demolished more than a dozen oceanfront homes in Orange County, and forced the demolition of at least one house. Malibu’s public‑safety director Susan Duenas said residents must stockpile food for at least two weeks.
The emergency declaration empowers the California Department of Transportation to assess vulnerable infrastructure, while permitting agencies can fast‑track levee repairs and channel‑widening projects. The state also plans to convene community workshops on September 29 to educate coastal residents on evacuation routes.
Federal assistance is expected to be requested by the end of September, and a joint task force of state and federal agencies will convene on October 5 to coordinate the response.