ABSTRACT
A culvert is designed to pass a stream flow under a barrier such as roadways. The hydraulic capacity of a culvert varies with respect to the headwater depth at the entrance and the tailwater depth at the exit. The major function of a culvert is to maintain the continuity of stream flow. A culvert system includes three basic elements: entrance, barrel, and exit. From the hydraulic standpoint, a culvert shall be lined with the existing stream alignment through a smooth wing-wall pool at the entrance. A culvert is designed to function under the allowable headwater depth, not the available headwater, determined by maximizing the flow loading as well as safety. Performance of a culvert depends on the culvert length, cross-sectional geometry, hydraulic resistance, and inlet and outlet conditions. During the construction of a permanent highway drainage structure, it often requires a temporary culvert to maintain the continuity of traffic flow and runoff flow.
