The immediate counterargument is that we already tried pumping water into a desert basin so we know perfectly well what will happen. You end up with the Salton

The immediate counterargument is that we already tried pumping water into a desert basin so we know perfectly well what will happen. You end up with the Salton Sea. A notoriously toxic and unpleasant body of water. Irrigating water across a small area is one thing, what this article proposes is a whole other thing. Lakes that have no outflow, like the Salton Sea, and the Great Salt Lake, end up being collectors for pollutants.They also aren't exactly major attractants for population. Most of the great salt lake shoreline is uninhabited, and most of the development on the East side hugs the mountains rather than the lake. Both lakes have pretty serious issues regarding pollution that will need to be solved. I'm not sure why we would ever want to make another one of those. There are plenty of places in North America that have plenty of room and resources for people. Coastal sections of the Pacific Northwest are pretty empty still despite ideal climate, water, arable land, etc...