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  • 1.  AutoCAD Civil3D input into HEC-RAS

    Posted 11-24-2015 01:56 PM

    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

    T 610.630.1660

    M 610.724.4740


  • 2.  RE: AutoCAD Civil3D input into HEC-RAS

    Posted 11-25-2015 05:16 AM

    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.

    Best Regards,

    Aloysio Saliba Ph.D., C.Eng, Aff.M.ASCE
    Senior Hydrologist
    Belo Horizonte
    5531 32978434

  • 3.  RE: AutoCAD Civil3D input into HEC-RAS

    Posted 11-25-2015 09:13 AM

    Try this instructional video:

    Hint:  It is towards the end, he shows how to fix that problem easily: 

    Vincent Peluso P.E., M.ASCE
    Orlando FL
    (407) 254-9925

  • 4.  RE: AutoCAD Civil3D input into HEC-RAS

    Posted 11-25-2015 12:16 PM

    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... 

    Robert Elliot P.E., M.ASCE
    Senior Hydraulic River Engineer
    Watershed Science & Engineering
    Seattle WA

  • 5.  RE: AutoCAD Civil3D input into HEC-RAS

    Posted 11-25-2015 02:41 PM

    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.

    Eveann D'Onofrio P.E., M.ASCE
    E S Design
    Audubon PA
    (610) 724-4740

  • 6.  RE: AutoCAD Civil3D input into HEC-RAS

    Posted 01-13-2016 03:38 PM

    Eve -

    HEC-RAS can flip the reach and sections after import.  

    Matthew Anderson P.E., M.ASCE
    Autodesk Product Manager
    Frankfort IL