pond design nightmare

[GeoTrek]

Is there a way to have the slopes on the berm to be different than the cut slope on the interior of the pad?

Ie

Surface relatively flat (1m change across)
Berms 1m above surface with 3:1 slopes and are 3m wide.
Once the interior slopes of the berms hit the surface and are starting to cut I want the ratio to be 0:1 vertical
Can this be done?

Maybe there is a better way to accomplish what I want.

Criteria
1. 15,000cm capacity
2. Max 5m cut on ground (pond bottom)
3. 3:1 berm slopes on 3m wide berm
4. 3:1 ramp on one side of pit; vertical slopes on other 3 sides of pit
5. Balance material

I would also like an option with 2:1 slopes on the berm expect on one side that has 3:1 slopes (equipment access; on the same side that the pit has 3:1 slope)

Any help is greatly appreciated!