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When using AutoCAD Civil3D to import the alignment and cross sections into HEC-RAS, the stationing, alignment and cross sections are reversed. A utube video by Andy Carter shows using a HEC-RAS Flipper he developed to correct the data, however, when you go to access the flipper routine, it is no longer available. Does anyone know how to correct the Civil 3D input into HEC-RAS?
Eve S. D'Onofrio, P.E.
E S Design LLC
128 Regency Drive
Audubon, PA 19403
I believe there is an option to fix this insise HEC-RAS in the geometry window and Tools menu.
This problem probably comes from how you draw the lines in Civil software: you may have drawn them upstream to downstream but HEC-RAS numbers river stations ascending in the opposite way, using line length. So, you can also try to reverse it inside Civil.
I hope this helps.
Try this instructional video:
Hint: It is towards the end, he shows how to fix that problem easily:
I don't use Civil3D and cannot directly answer your question. However, I can tell you that HEC-RAS itself has a very quick way to flip the cross-sections from facing upstream to correctly facing downstream. Within the Geometry Data, simply go to Tools-->Reverse Stationing Data ... If you immediately click the Arrow, then OK, all cross-sections from all Rivers and Reaches will be flipped around. Only takes 5 seconds, and is probably quicker than the Civil3D flipper add-in anyway. Hope this helps...
Thanks for all the suggestions. I was able to fix all three problems. In AutoCAD C3D, I drew the stream polyline from the downstream to the upstream for the alignment. The 'Modify Alignment Properties>Reverse Direction' reversed the station direction. In HEC-RAS I used your suggestions and reversed the cross section stationing and also changed the flow direction.
HEC-RAS can flip the reach and sections after import.