The amount of energy needed to pump enough water for ag uphill is insane. Well beyond "just" throwing some solar panels out there. If it was that easy we'd pump Mississippi water into west Texas (which there was a plan to do in the 60s with nuke plants, but I cannot find the name right now).
i left off the /s as to me anytime someone starts a comment off with "just ____" is usually a farcical idea. like just remove the salt from water and boom, done.