All of the runoff from the site's surfaces including the roof and driveway end up here before they eventually flow into a creek. This little swale serves a big purpose of slowing down the runoff, preventing sedimentation of the local creek and capturing any pollutants that might enter it. Lucky us - hooray for nature! This garden was featured in the 2013 Santa Barbara Botanic Garden annual garden tour. Andri Beauchamp, photo