Yes, and we should be investing heavily into technologies and techniques that maximize the efficiency of the water that is consumed by agriculture. The government should probably subsidize the expense of the conversion. We should also get rid of any "use it or lose next year's ration" rules that are in place which cause some farmers to literally just run water out of their pipes to ensure they're recorded as having "used their allocation" and therefore "still require that much next year".
Using a normal common law water rights system is literally prohibited by some state constitutions (e.g. AZ article 17). It would take a movement on the order of civil rights to fix water rights.
Humans should have access to a consistent generous ration for hygiene, drinking water, and moderate home gardening. I think it's reasonable to cut people off (during a major drought with rationing) when they start focusing on trying to maintain large lawns, golf courses, swimming pools, etc.
