What is the Culvert Analysis Program (CAP)?
The Culvert Analysis Program (CAP) is a solver developed by G.L. Bodhaine at the U.S. Geological Survey (USGS) for developing rating curves for a wide variety of culvert and culvert approach types. The solver was subsequently correct and improved by Janice Fulford of the USGS and then prepared and further corrected for use in iRIC by Keisuke Inoue of Mizuho Instrumentation and Research with direction from Jonathan Nelson, Bob Holmes and many other users at the USGS. Given a suite of information about culvert geometry, approach details and more, the solver produces a culvert rating that predicts culvert flow rates as function of water-surface elevations.
Zip file containing data for CAP tutorial
User’s Guide to the U.S. Geological Survey Culvert Analysis Program, Version 97-08 - U.S. GEOLOGICAL SURVEY WATER-RESOURCES INVESTIGATIONS REPORT 98-4166
MEASUREMENT OF PEAK DISCHARGE AT CULVERTS BY INDIRECT METHODS - TWRI Book 3 Chapter A3
Tutorial to guide the user through the basic functionality of the CAP solver