Group responsible for many
massive earth moving projects. While many of their works may have made some things more
convenient (like forcing rivers to
meander less to make water
transport and allocation more
efficient, or the creation of
dams and
levees to facilitate crop irrigation) they have made a great many things that turned out to be terrible for
biodiversity (like diverting rivers through concrete furrows that devastate some natural
habitats or occasionally fill with silt and then
flood.
For an example of what the ACoE can do, check out the Los Angeles River. You can drive a car through stretches of it. Not along the banks of the river or across it's width, but actually through the water, in the same direction that it is flowing, as if you were in a boat.