American West Will Face Mega Droughts in Coming Century

[pbrower2a]

I don't get why some of these cities, like Phoenix or Las Vegas, just don't build a massive pipe/hose that connects the Pacific Ocean to the city

First, the seawater must be desalinated, an energy-intensive process.

Second, the highly-concentrated brine must be dumped somewhere.  That would be an environmental mess.

Third, the Gulf of California (in Mexico) is closer than the Pacific Ocean.