A berm is a mound or bank of soil without formal sides. You often see large berms on the sides of highways, which are used for noise control. On a reduced scale, a natural berm can provide some interesting benefits in a backyard landscape.
Berms may be shored with stone, bricks, or timbers, and planted with groundcovers, perennials, annuals, trees, etc.
You can control the height of a berm as well as its peak shape.
To create a berm/trench:
Select Insert
> Terrain > Berms/Trenches, or click the Berms/Trenches button
on the Terrain toolbar.
In the Berms/Trenches dialog, specify the height of the berm in the Height edit box. Entering a negative value creates a trench.
Using the Zenith slider control, select a peak shape for the berm.
Click OK.
Select two points to define the length of the top of the berm. The berm will be created downward and outward from this line.
Right-click and select Finish.