I just got my latest book from the guy who writes XKCD. The inside dust cover is a map of the world as represented if there was a wormhole from Earth to Mars at the bottom of the Marianas Trench. As you might guess, there isn't much water left.
My biggest project, were I to become president of the US would be to initiate a water project that drains the Great Lakes, maybe a foot or two, and irrigates the desert Southwest. Starting by filling the Great Salt Lake, it would be the coolest thing since the Panama Canal. Sez me.
On the other hand, since there isn't likely to be any wormholes sucking away our oceans, it might be a better project to place some nuclear powerplants on the coastline and desalinate a river of water going back from the ocean into some parched nations that could use it. I just love the idea of a river that starts from the ocean and flows inland - an artificial estuary that begins on a sea cliff.
You see if you're going to build a nuclear power and desalination plant it's going to take a community of hard working, well educated civilians protected by some special arrangement. A sea cliff would be a very nice place to live, walking distance from your job at the plant.