The Importance of the Flood Plan

Human history is basically a story of humans figuring out the best ways to manage their water supply. There are great chinese myths about controlling the flow of rivers. So on the banks of the niler, there would be this flooding season that would allow you to moisten your fields and nourish your crops. But if the flooding season fails in either direction, if the waters either do not climb high enough, or if they climb too high, it's disaster right?