I've taken too much of a deep dive on this. But I can't find any source for that study. The article does link to a study of a canal across Kansas, but that study notes that the unit costs of water, for that much shorter route would be too high for farming to support. It would need to be subsidized by cities and industry and its price tag for a division of half of what this fanciful article puts as the lower bound was 28,276,000,000.

We need to price water properly first, then we can see if it even makes sense to farm in the desert or to ship water out there. At the moment it seems not to, not while we have better places