I'd guess that it's more efficient to desalinate water and distribute it via pipelines than to go the extra step of getting it up to cloud height and then letting it fall down again.
Exactly. I wonder how feasible it would be to repurpose oil pipelines and send desalinated water back inland.
It's all feasible, if you have cheap enough energy.
The installations themselves are not that expensive. The energy required is very expensive. And unless it's 100% 0-Carbon it will only exacerbate the situation.