Retaining Walls and Swales
Retaining walls are relatively rigid walls used for supporting soil laterally so that it can be retained at different levels on the two sides. Retaining walls are structures designed to restrain soil to a slope that it would not naturally keep to (typically a steep, near-vertical or vertical slope)
The design and performance of most retaining walls are based on keeping the area behind the wall relatively dry. To ensure a quality project, the soils used must not become saturated during construction and the final design must route water away from the back of the wall. Incorporating berms and swales into the final design is an easy way to direct surface water away.
Self Drainage System
It is important to have proper drainage behind the wall in order to limit the pressure to the wall's design value. Drainage materials will reduce or eliminate the hydrostatic pressure and improve the stability of the material behind the wall. Drystone retaining walls are normally self-draining