We need to stop encouraging people to live where there isn’t any water. There’s a reason nearly 3/4 of the US population lives east of the Mississippi, and that reason is the Eastern half of the country gets a straight up order of magnitude more rain water than the Western half
They sont have any pipelines running into California because the terrain makes them prohibitedly expensive. If BP and Exxon Mobile say it is cheaper to import Saudi crude to California because it is too expensive to pipe Texas crude, then there is no way. Canada has one pipeline to connect Albertam oil to Vancouver, but it is so expensive to pipe that oil across the Canadian Rockies that the pipe it downhill to Saskatchewan where it can then be pipped downhill all the way to Texas. Pipelines across mountains are just not feasible unless you are trying to move stuff from the top of the mountain to the bottom.