The Evaporation in SWR: Surface-Water Routing Process pane is on the MODFLOW Features tab of the Object Properties dialog box.
Starting time and Ending time are explained in the help for the MODFLOW Features tab.
SWR Evaporation (EVAP/EVAP2D): EVAP and EVAP2D represent the volumetric rate per unit area of water removed by evaporation directly from the reach (in units of length per time). EVAP and EVAP2D are positive values.
