Neb. Rev. Stat. §§ 31-1015
Obstruction shall mean any wall, wharf, embankment, levee, dike, pile, abutment, projection, excavation, channel rectification, bridge, conduit, culvert, building, wire, fence, rock, gravel, refuse, fill, or other analogous structure or matter which may impede, retard, or change the direction of the flow of water, either in itself or by catching or collecting debris carried by such water, or that is placed where the natural flow of the water would carry such structure or matter downstream to the damage or detriment of either life or property. Obstruction shall not include a dam designed to store or divert water for which permission for construction has been obtained from the Department of Natural Resources pursuant to the Safety of Dams and Reservoirs Act.
Neb. Rev. Stat. §§ 31-1015