A rain garden is a vegetated depression used to promote absorption and infiltration of stormwater runoff. Rain gardens are usually located at a low point where stormwater naturally collects. Stormwater can also be redirected from downspouts and impervious surfaces by runnels or French drains. A variety of deep-rooted native vegetation can be used to add seasonal and height variations. Since much of the infiltration depends on the soils, soil with little compaction and quick absorption rates are necessary for a successful rain garden.