People try to unclog storm drains to help ease the flooding along 14th Street in the Mission District in San Francisco on Dec. 31, 2022.

Earlier this month, the National Oceanic and Atmospheric Administration raised the odds that the El Niño building in the Pacific will become “very strong” by late fall, potentially placing it among the most powerful events in recorded history. And while El Niño does not guarantee a wet winter in Northern California, an event of this magnitude could easily raise coastal water levels by a foot or more and intensify winter storms already supercharged by climate change. 

No long-range forecast can tell us exactly what this winter will bring. But the past few years have made one thing clear: San Francisco is wildly underprepared for what this El Niño could deliver.

During the winter of 2022-23, downtown San Francisco received nearly 18 inches of rain in barely three weeks (the city normally gets about 20 inches a year). New Year’s Eve of 2022 was the city’s second-wettest day on record, the peak in a series of storms that shut down power and major transit hubs, and caused tens of millions of dollars in damage to homes, businesses and city infrastructure.

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Cars attempt to drive through flooding waters as high as 3 feet along the Northbound 101 in South San Francisco on Dec. 31, 2022.

Like the storms in 2017 and the last “super El Niño” in 1997-98, the winter of 2022-23 confirmed that San Francisco’s infrastructure was built for a climate that no longer exists. 

San Francisco is California’s only coastal city that runs wastewater and stormwater through the same network of pipes.........

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