China already did a project like this to move water from the wet part to the dry, because their leaders were eager engineers and wanted to do it. Turns out that the wet part isn't making enough water to the dry part now because of climate change. Same thing would happen here. The rockies already create a rain shadow over the great plains, there isn't a way to get water from the other side of the rockies, because that is what it would take. and Cali has been in a drought for along time too. There just isn't water available.