The program FRACHT allows the design of cascading rain relief systems in mixed water channels. It is possible to measure catchment basins, flow basins and storage drainage conduits with top and bottom discharge.

The basis for this is the simplified division procedure according to guideline DWA-A 102 - draft of October 2016 and guideline ATV-A 128 of April 1992. Various country-specific special regulations have been implemented.