TABLE OF CONTENTS Culvert location means alignment and grade with respect to both roadway and stream. Proper location is important because it influences adequacy of the opening, maintenance of the culvert, and possible washout of the roadway. Although every culvert installation is a separate problem, the few principles set forth here apply in most cases.
A culvert is an enclosed channel serving as a continuation of and a substitute for an open stream where that stream meets an artificial barrier such as a roadway, embankment, or levee. It is necessary to consider abutting property, both as to ponding upstream and as to safe exit velocities, in order to avoid undue scour or silting down-stream.
An open stream is not always stable. It may be changing its channel straightening itself in some places and becoming more sinuous in others. It may be scouring itself deeper in some places, silting in others. Change of land use upstream by clearing, deforestation, or real estate development can change both stability and flood flow of a stream.
Because a culvert is a fixed line in a stream, engineering judgement is necessary in properly locating the structure.
The first principle of culvert location is to provide the stream with a direct entrance and a direct exit. Any abrupt change in direction at either end will retard the flow and make a larger structure necessary.
A direct inlet and outlet, if not already existing, can be obtained in one of...
