Sec. 3.5. As used in this chapter, "logjam" means an accumulation of lodged trees, root wads, or other debris that impedes the ordinary flow of water through a waterway. The term does not include the development of sandbars, sedimentation, or accumulations of stone or gravel. Logjams are evidenced by a blockage that does any of the following:
(1) Traverses the waterway.
(2) Causes upstream ponding.
(3) Results in significant bank erosion.