Natural Drainage Systems reduces the negative impacts of urban storm
water runoff on Seattle's creeks and marine water bodies by using open
vegetated swales, storm water cascades, and small wetland ponds to mimic
the functions of nature lost to urbanization. This program, a 2004
Innovations in American Government Award winner, also helps slow traffic
and increase pedestrian safety while plants, trees, and soil absorb
storm water and filter pollutants.