User's guide to the culvert analysis program

This user's guide contains information on using the culvert analysis program (CAP). The procedure used is based on that presented in Techniques of Water- Resources Investigations of the United States Geological Survey, book 3, chapter A3, "Measurement of Peak Discharge at Culverts by Indirect Methods." The program uses input files that have formats compatible with those used by the Water-Surface Profile (WSPRO) program. The program can be used to compute rating surfaces or curves that describe the behavior of flow through a culvert or to compute discharges from measurements of upstream and downstream water-surface elevations.