Preliminary Data Summary of Urban Storm Water Best Management Practices synthesizes existing information on costs and environmental benefits of stormwater Best Management Practices (BMPs). The major goals of stormwater BMPs are flow control, temperature and pH control, and pollutant removal, including solids, oxygen-demanding substances, nitrogen and phosphorus, pathogens, petroleum hydrocarbons, metals, and synthetic organics. The environmental benefits cited include hydrological and habitat benefits, human health benefits (direct contact and seafood), and aesthetic benefits (property value/public perception, dual use systems using less space). The report provides a recommendation for stormwater BMPs and their associated costs and benefits.