When I heard that, I was a little confused. But we now live in a part of the country where all the water has dried up, and all the lakes are man-made.
When we drive around, we go over bridges that cross very large dried up river beds. I don't know how long ago the rivers were there, or if they ever come back in a rainy season, or if there ever is a rainy season. But I do know that the Red River was once very large, and now it is a wide red clay river bed that is dry and cracked.