Russ:
Should work fine. Make certain that you have defined the elevation layer source that the RiverCAD software is to use in determining where to intersect the computed water surface elevation with.
If you get stuck, give me a call and we can investigate the problem via a web session.
If you have any additional questions or need any further information, please contact me again.
Sincerely,
Chris E. Maeder, M.S., P.E.
Senior Technical Engineer
chris.maeder@bossintl.com