To simulate historical events it is necessary to firstly separate excess rainfall from the total rainfall recorded and then route this excess to produce the simulated runoff hydrograph.

Data is inputted directly or via the HYDSYS dialogs and can also be read directly from a HYDSYS output file. The format of this file structure is further described in the Hydsys Hydrographspage. 

XPRafts allows for the input of recorded runoff hydrographs, at any node within a catchment. This may be graphically outputted together with the simulated runoff hydrograph to help calibrate appropriate loss rates and routing parameters.