Floodplain Mapping

[lhackle]

I can not seem to stop the mapping module from filling low spots on the opposite side of my levee. The stream is very winding. I have been trying to limit the length of my cross sections to accomodate with no luck. The cross sections look fine. I have several different profiles to run and the higher flows will overtop the levee, but the low flows should stay on the right side.

[Chris Maeder]

I would really need to see your drawing file to determine the specifics to the problem you are having.

However, make certain that you have selected the option "Restrict Contours to within Model Results" in the Advanced Water Surface Options dialog box. This is supposed to be on by default, but if it is off, then you will see ponding of flood water outside of the levees, etc.

Also, if there are problems with your terrain data, so that water can somehow "leak out" to these overbank areas, then you will end up with ponded water areas. This is difficult to fix unless you add additional points to the original terrain data so as to block these spots where the water can leak out.

Sincerely,

Chris E. Maeder, M.S.
Senior Technical Engineer
chris.maeder@bossintl.com