The system for supplying water to SoCal was solved about a 100 years ago. The result: huge farms sprang up, and SoCal became a major supplier of food. Within half a century, major corporations moved in, ports expanded, and Silicon Valley was born, and SoCal became a major contributor to state revenue and supplier of goods.
Thanks to all that tax revenue, Calif could build dams on rivers created by NoCal's rain and snow to provide cheap, clean energy to the entire state, create lakes for recreation, which brought more revenue, fill reservoirs, create new aqueducts, and store water reserves in massive water towers.
Very recently, some of those dams were blown up and millions of gallons of water per year intended for the reserves was re-directed to the sea. This was done to save a fish that was purported to be endangered. So, Los Angeles is burning, and the water reserves are all used up, but the fish are ok. No need to worry about the fish, they'll be fine.