Are you saying California shouldn’t export food? It’s one of the best food growing environments on the planet.
Well if you wish for California to become the next Sahelian desert, sure. California is already on track to become one adverse climate event away from turning into a complete clusterfuck.
CA's central valley is missing ~140 million acre feet of groundwater relative to historical norms, and is pumping an additional ~15 million acre feet a year. Ban that and desalinate 30 million acre feet of oceanwater at $2000 per acre-foot and you can have your cake and eat it too at a cost of 60 billion dollars a year, expand agriculture and develop a sustainable aquifer & watershed.
But central valley agriculture only makes $37 billion a year.
That said, rice consumes a lot of irrigation water:
"In California, there is very little to no rainfall during the rice growing season, so this is not usually considered in water budgets. On average, about 5 acre feet/acre (AF/ac) of irrigation water is applied to a rice field during the growing"
https://ucanr.edu/sites/RiceTestSite/files/328501.pdf
Also, rice is not a particularly big water consumer compared to other crops - it's just one that came to mind. You could pick from dozens of others - Almonds, pistachios, etc.
California simply uses a LOT of water to produce a LOT of food, about half of it being exported.