Bund of material / how to design storage of excess material?

Hi, I am hoping someone can help.

I am using Power InoRoads V8I (SS4) and only know the basics for producing cut and fill balance for excavations. 

What I have been tasked to do is to take excess material from cut / fill on the site and design a mound to loose that excess without going above a certain height from existing ground level

I can create existing ground DTMs and proposed foundation area DTMs (although maybe not the best way) 

I would initially tackle this by taking my excess material volume and calculate what sort of mound would fill that volume then create a shape with height then generate longitudinal feature and generate sloped surface then find out the volume from there. This would take alot of educated guess work and even more time...

Is there an easier way to do this?

Thank you in advance.

Brian