by Anne Cline
Under the recently updated Stormwater Management Manual for Western Washington, many projects creating or replacing between 2,000 and 5,000 square feet (sq. ft.) of hard surfaces such as a driveway or new building addition, or disturbing soils within an area ranging from 7,000 sq. ft. to 33,000 sq. ft. may use a rain garden to manage stormwater. A rain garden is a Low Impact Development (LID) tool used for managing stormwater by passing runoff through a designed landscape area, thus reducing runoff by evapo-transpiration and infiltration to the local subsurface environment.