I would like to import HEC-RAS cross sections into AutoCADD or Microstation and
then I would like to plot the sections to scale. What procedure should I follow to
accomplish this?
You could try copying the cross-section to the clipboard (via the file menu in the cross-section window). Then, from inside AutoCad (I tried this in AutoCad LT14) go to Edit|Paste Special and select pasteing as "AutoCad entities". This will give you a block on a drawing sheet which you can then explode into individual lines etc. I think it should then just be a matter of scaling the elements appropriately within AutoCad.