NASA scientists who think we can't move water to people
When you've got 10 units of water and 15 units of demand, you move the water, but that's 5 less for someone else. Califormia has a huge overdraw on their supply, and is already moving water in from other places, and isn't letting a drop leave to the south. (they're not too happy about california UNmoving their water, see how well "move the water" is working with the Rio)
This isn't a case of product sitting in a warehouse across the country collecting dust, it's a limited natural resource, and they're already drawing heavily from all the "easy" AND all the "not so easy" sources. Yes you can move the water, but you can be darn well sure they don't want to pay for that. That's a big part of the problem, there's too much red tape holding the cost of water down right now. If the price would rise with the scarcity of the resource as it really should, CA wouldn't be having this problem. But that wheel is broken, and the machine is dysfunctional as a result. And everyone's been livinng on borrowed time, like borrowing from the bank to prop up an unprofitable business, without actually fixing the business. That can't go on forever.
So much of CA's water is getting shipped out of state or evaporating due to their agriculture. That's where the whole "this is an arid state" thing comes into play. Sure you can move there and live there, but trying to grow thirsty fruit and nut trees there is just plain dumb, and SHOULD be uneconomical, but they aren't being charged for their water relative to the actual value of the resource, to keep it a viable business. All these farmers out there crying "this water shortage is going to put me out of business!", yeah, it is. And it SHOULD. You've been relying on a crutch for decades and now the crutch has rotted and collaped under your weight, and so you're going down. The politicians down there are more than willing to help keep you propped up, and have been doing so for decades, but now it comes down to basic physics - there's simply no water left for them to give you to keep you afloat. They'll bend over backwards to keep the industry going, but it just won't be enough, not anymore. You can keep your agriculture, but you're going to have to change what you're growing. A single walnut costs almost five galons of water to produce. Look at that walnut tree and tell me how many galons of water that takes. You just don't DO that in a location where water is scarce, unless you're an idiot or have a government that's being an idiot for you and giving it away. "Just move the water!" uhhh... how about "Just MOVE the TREE?!" It makes a lot more sense to plant a tree over there than to try to move all that water over HERE.