An edge or shoulder alongside a paved surface, designed to retain liquid that may collect on the surface. Normally, a berm is no more than 6 or 8 inches in height.
A larger dirt berm may be used temporarily during an underground storage tank installation to direct runoff water away from the excavation.
A berm might be constructed along the edge of a gasoline station driveway to direct the flow of accumulated rainwater toward the inlet point of a storm sewer system. Or a berm might be constructed around the perimeter of a small aboveground tank, to retain spilled product or to control the direction of its flow.