If you are running HEC-RAS within RiverCAD, it will allow you to already plot multiple profiles on the topo map. In the Output | Floodplain Map Results dialog, you can check which profiles you want to plot output for.
If you are bringing in output from outside of RiverCAD and usiikng the Floodplain Mapping Module, then you need to "uncheck" the Erase Previous Results checkbox and the software should retain the previous floodplain map results. If it is not, then please let me know and I will have our developers look into this issue.
Alternatively, you can take the plotted output from RiverCAD and change the layer it resides on and then it should not erase the data.
Sincerely,
Chris Maeder, M.S., P.E.
Senior Technical Engineer
chris.maeder@bossintl.com