Different Slope Angles to Bund

Hi all,

I'm sure that there is a simple answer to this one - just can't find it!  I need to design an 'L' shaped bund 5m high with 1:1 outer flank and 1:3 inner flank.  The berm tool only allows 1:1 or 1:3, not both.  Creating a bund with 1:1 flanks and then trying to use the Slope tool doesn't work - any ideas?

Thanks in advance.