California Aqueduct provides below market price water to Agriculture in California, and prevents Los Angeles from drying up and blowing away.
Nope.
Manufacturing in the USA hasn’t been declining over the last several decades: the USA is among the top three manufacturing nations of the world by value, and has been for ages. The Political Rhetoric in the USA that “we don’t make anything anymore” is bullshit.
What we don’t do any more is employ armies of unskilled or semi-skilled people in manufacturing. Those jobs are never coming back to the USA, and they’re largely gone elsewhere too, because of the very same Productivity improvements.
See What are the rank-ordered causes of manufacturing employment decline in America?