As someone pointed out in a conversation elsewhere, datacenter water use is a small part of total water use (in WA and CA), which is dominated by agriculture.
Simple, obvious answer to your rhetorical question is: where there's water and power. But city water and city power are not the same as what ag needs / wants / suffers. City water and city power have reliability and purity / quality standards which ag doesn't need (not enough to pay for it).
Do the objectives / needs of datacenters comport with the constraints and drivers which evolved city water / power? How do the constituents who paid for (and probably are still paying for) the buildout feel about the resource _which they own_ being utilized for a purpose which maybe doesn't comport with the _contract_ they thought they were getting?
Simple, obvious answer to your rhetorical question is: where there's water and power. But city water and city power are not the same as what ag needs / wants / suffers. City water and city power have reliability and purity / quality standards which ag doesn't need (not enough to pay for it).
Do the objectives / needs of datacenters comport with the constraints and drivers which evolved city water / power? How do the constituents who paid for (and probably are still paying for) the buildout feel about the resource _which they own_ being utilized for a purpose which maybe doesn't comport with the _contract_ they thought they were getting?