I really don’t know where you’re getting your info. I grew up in CA and there’s no way SoCal gets more water of any kind unless it’s piped in. This precip map also proves that. The Sierras and Northern California get way more rain/snow than the San Gabriel or Bernardino mountains “scrape” out of the sky. The Sierras are a huge range compared to them, and when they do get snow, that water feeds into the lakes and rivers in the Valley. The precipitation map clearly shows SoCal can’t match any precipitation further up the state past Tehachapi.