OBSTRUCTION – shall mean, but is not limited to, any dam, wall,
wharf, embankment, levee, dike, pile, abutment, protection, excavation,
channelization, bridge, conduit, culvert, building, wire, fence, rock,
gravel, refuse, fill, structure, vegetation or other material in,
along, across or projecting into any watercourse which may alter,
impede, retard or change the direction and/or velocity of the flow
of water or, due to its location, its propensity to snare or collect
debris carried by the flow of water, or its likelihood of being carried
downstream.