A berm is a level space, shelf, or raised barrier (usually made of compacted soil) separating areas in a vertical way, especially part-way up a long slope. It can serve as a terrace road, track, path, a fortification line, a border/separation barrier for navigation, good drainage, industry, or other purposes.

What is a berm?

1 : a narrow shelf, path, or ledge typically at the top or bottom of a slope also : a mound or wall of earth or sand a landscaped berm. 2 : the shoulder of a road deer …

What is the main purpose of a berm?

Berms prevent off-site sedimentation by diverting runoff to a sediment trapping device and can also be used to divert clean water from entering a disturbed area. They can also trap sediment by ponding and settling out sheet flow runoff, or by filtering sediment as runoff passes through permeable berms.