Erosion is ever prevalent in any landscape, whether it is due to wind or water. This makes retaining walls all the more important, especially if your landscape does not feature a lot of trees and shrubs to hold the soil in place. In addition to providing necessary support to the soil, retaining walls also help reduce the surface runoff by reducing sharper gradients. This reduces the speed at which water travels over the surface and thereby reduces erosion.
Retaining walls do all this while also providing effective flood control in the form of water drainage aimed at preventing flooding. Channels and drainage pipes can be integrated into the construction to provide further measures for proper drainage and water control.
Lastly, retaining walls also reduce the gradient through terracing which allows water to soak into the soil rather than run off the surface.