Coincidentally, in November 2022, researchers at UC Irvine conducted a study on how a major flood would impact Los Angeles.
From ABC news (s):
“In a state severely hobbled by drought and wildfires, flood concerns may not seem top-of-mind. But a new study out of UC Irvine found that Los Angeles County's aging flood systems may not be ready for a major flood.
"Right now, our research suggests that our infrastructure and the way we've built it out is much more vulnerable to this type of event than I think anyone would have guessed," said Brett Sanders, a Professor of Civil and Environmental Engineering at UCI and one of the authors of the paper.
The study expands on federal flood risk maps that do not include flooding from rainstorms, only coastal and river flooding, according to Sanders.
“For any Angeleno that drives around [in a] Southern California rainstorm, you know that you quickly find yourself in a street corner filled with water. And those risks aren't mapped," said Sanders.
"So you can imagine the small amount of flooding we have in our streets on a typical winter storm. What might that look like in a once-in-100-year-storm?" he continued.
According to the study's mid-range estimates, 425,000 people could be exposed to flooding of more than a foot, causing $56 billion in property damage in the event of a major flood.
But, those are the researchers' "best guess," said Sanders. The study accounted for uncertainties in how much water would flow through the area in a once-in-a-century flood.
The study's low estimates put 197,000 Angelenos at risk of experiencing flood levels of more than about a foot and property damage at about $36 billion. On the high end, a major flood could impact 874,000 people and cause $108 billion in property damage.
The study also found that communities of color would be more likely to experience waist-high flooding.
Black, Latino and Asian Angelenos would be 79%, 17%, and 11% more likely, respectively, to experience deep flooding than white Angelenos.”
I seriously hope that the storm weakens before it makes landfall. I hope this concern becomes completely unnecessary and that it’s nothing more than a little drizzle.