A wall at the end of a drainage structure designed to prevent erosion of the embankment at its entrance or outlet. pp. 21, 22, 35-37, and 41-45.
A wall placed at the end of a culvert. It may serve three purposes; one, to hold the embankment away from the pipe and prevent sloughing into the pipe outlet channel; two, to provide a wall which will prevent erosion of the roadway fill; and three, to prevent flotation of the pipe.