South-east Iowa, where I'm from. The further upstream you get, the higher the bluffs and smaller the flood plain, so levees (and big ditches and pump stations) become unnecessary.
I never bothered taking any pictures, because it was just part of the landscape. I will the next time I'm at my parents' house.
Near there, at lat 41.02310 lon -91.00600 there's a bridge across the big ditch, which I climbed. It's a two lane bridge on a gravel road, so it wasn't huge. But I hesitate with heights, and I did it free climbing barefoot, right after a thunderstorm. You can see the shadow of the trusses on the dry bed of the ditch next to the red dot. You can also see where they used imagery from two diferent passes on the right third.