You can set left/right cut/fill slope setting for the whole project and change it at any point in the project (or use a variable slope) between existing and proposed using EARTH software (http://www.earthworksoftware.com) -- you don't have to do hand calculations, but you also don't have to get...
HYDRA, SWMM, and all the SWMM variants do essentially the same things: calculate hydraulic dynamics in urban drainage systems (pipes, channels, pressure lines, etc.). HYDRA and SWMM approach the problem differently, which means there are key differences in terminology that makes it difficult...
If you like to work using traditional methods (not CAD based) or just want something for quick estimates, here is a simple inexpensive earthwork software that is used by several state DOTs and consultants. It's called EARTH by Pizer Inc:
http://www.earthworksoftware.com/
The simple data...