Improved understanding of combined sewer systems using the Illinois Conveyance Analysis Program (ICAP) Article

cited authors

  • Oberg, N; Schmidt, AR; Landry, BJ; Leon, AS; Waratuke, AR; Mier, JM; GarcĂ­a, MH

fiu authors


  • Understanding the conveyance of sewer networks is vital, especially in cases of great variability in flow rates, such as in combined sanitary and storm sewer systems. Conventional conveyance studies in sewer systems often have extended computation times due to complexity of the solution, or alternatively make assumptions that ignore the water-surface profile within a pipe. In previous research, the hydraulic performance graph (HPG) was successfully used for open-channel capacity determination. The HPG summarizes the results of many backwater calculations for a reach so that these calculations do not need to be repeated. This article describes algorithms utilized by the Illinois Conveyance Analysis Program that uses the HPGs to describe the conveyance of a system, identify bottlenecks for varying conditions, conserve mass by tracking outflow and overflows under stepwise steady flow conditions. The software is freely available at

publication date

  • September 14, 2017

Digital Object Identifier (DOI)

start page

  • 811

end page

  • 819


  • 14


  • 8