That's one of the reasons I'm staying where I am.
> trying to move it there
Being that they straddle the US / Canadian border, it's legally much more difficult to mass pump water out of them. Probably the main reason it hasn't happened yet.
For now.
There's also little reason for it. There's plenty of rich farmland here to grow on. Agriculture should move back to this region, and growing practices and crops adapt for the colder climate. Growing heavily irrigated crops in the desert or semi-arid regions has many advantages but makes little sense in a water constrained world.
Right now the rich well watered soils of the midwest and great lakes region are being wasted on cash crop soy/corn rotation. Chipping away at the rich top soils for animal feed etc. There's a lot more that could be done here. This land is good for so many things... growing almonds in California? Grow hardy hybrid hazelnuts in the east. Cold hardy, disease resistant grapes make exotic regional wines with a unique eastern terroir and a long history, mostly forgotten. Bring back the apples orchards. The peaches and apricots. Re-open the canning and juicing plants. It's a shorter, mostly single season for most annual vegetable crops, but so much fertile land and water. And greenhouses add a lot of value.
It never left, Illinois and Minnesota are the 3rd and 5th largest producers of staple crops (the other being California, Iowa, and Texas, respectively, and CA and TX are only slightly larger in production but massively larger in size). West of the Mississippi, ranching dominates agriculture due to the poor soil and dry climate.
Largely that corn and soy in the Great Lakes region is being used as animal feed for the ranches out west. They already have massive utilization of land area for the production of these crops.
And in the more northeast states, it actually left.