Arlington, Texas, is comprised of 100 square miles of suburban development, with creeks and storm drainage structures throughout the city handling runoff from an abundance of impervious (paved) surfaces.  Infill development is ongoing, including a new NFL stadium for the Dallas Cowboys that has covered approximately 120 acres with structures and parking lots.  Like all cities with populations over 50,000, Arlington must meet the mandates of the EPA’s Municipal Separate Storm Sewer System (MS4) permit requirements under the Clean Water Act.  One requirement of the MS4 Permit is to identify our storm sewers and their associated outfalls, with the ultimate goal of discovering and tracking illicit discharges into the system – for example, discharges from industry.  Beyond the EPA’s requirement, though, is the immediate, practical need to inventory storm sewer assets – channels, inlets, outfalls, pipes, junction boxes - in order to manage response to problems involving both water quality and quantity.