Umm, no. I think the US has plenty of water, its called the Atlantic and the Pacific. Technology can make it potable.
One of the arguments against using sea water is that the process produces a lot of strong brine. The EPA is fretting about the damage it would do to put concentrated brine back into the coastal waters.
I’m just sitting here, rolling my eyes. Wishing that I could remind all of these wonks that this is one method of producing much-needed salt. Good quality salt, at that.
There’s no need to put the brine back in the ocean at all. Just let it evaporate, treat the minerals that are left, and keep the salt.
The problem is not just potable water, but also water for agriculture and to support wildlife habitat. When all the demands for water are taken into account, large scale engineering projects may be the best solution, moving water from where it is in excess (Canada) to where it is needed (California). Some Canadians may scream about it at first, but compensating benefits to Canada may make such a project politically palatable and genuinely beneficial to both countries.