Now you're in my area. turn cornfields and woodland into roofs and parkinglots, and you're shoving water downhill faster. Add in the tree huggers and Gubmint Greenies in the NRCS, DNR, Army Corp of Engineers, EPA, and Dept's of Environmental Management, they make it near to impossible to keep existing ditches, creeks, streams, and rivers clear of downed trees and obstructions.
And yet, many private institutions and corporations understand and manage to create well managed areas (in terms of flood control).