Yep, here's an article from 2015… and we're still dry as a bone over here…
"An inch of rainfall in L.A. generates 3.8 billion gallons of runoff, so you’re talking about more than 12 billion gallons of water that could be captured, but that flows within hours down our concrete streets and into the ocean. There’s enough rainwater to be harvested to produce 30-50% of the entire city’s water needs."
https: //www.forbes.com/sites/ashoka/2015/04/15/why-does-california-let-billions-of-gallons-of-fresh-water-flow-straight-into-the-ocean/#591cfd78517c