Surely we've got enough places having droughts that our control over nature will have us putting up massive water pipelines around the world. They'll need redundant desalination and cleansing plants.

Anyone know what to do with all the material removed?

I get the feeling we'll need to dump it back into the ocean in a controlled way. Seem to remember that from some reading I was doing years ago. I remember the article said a good test place would be the coast of Africa so farming didn't take too much water from the Serengeti messing up the wildlife.