Using XPSWMM to create Flood Maps

[mricks]

Has anyone ever used XPSWMM to create flood maps? I have an urban area (mostly closed conduits) and have been asked to create flood maps. I have created a DTM in SWMM but have been unsuccessful in displaying the flooding extents. Any ideas?

 

[francesca]

Civil 3D has a SWMM engine as a subscription advantage pack. What file format is your DTM and what software are you trying to display it in?

 

[beej67]

How big is your area?

I've used XP-SWMM to do flood plain modeling before, but I've never used the DTM portion of the program. I cut sections in Land Development Desktop, entered approximations of them in the section geometry editor of XP-SWMM, did my analysis, and then drew the extents of the flood back in AutoCAD by hand. Took me about a day.

I finally yoinked an educational copy of Civil3D, so I plan on goofing off with it sooner or later. So far all I've discovered is they changed the LayIso command to be a big pain in my ass.



Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East -

http://www.campbellcivil.com

 

[francesca]

If you have a river station/WSE from your hydraulic model, it's really easy to create the water surface plot by creating an alignment, profile and then corridor model in InRoads or Civil 3D. You use a template/assembly that shoots horizontally and daylights at the existing ground surface. Much easier than tracing contours and interpolating from cross-sections, which I've done in Terramodel with HEC-RAS results. Of course, Civil 3D can import HEC-RAS output and may be able to create a surface off it; I've never done the reverse trip, only used it to create my HEC-RAS x-sections.

 

[cvg]

only problem with shooting horizontally is that flow splits (I mean secondary channels) are missed.