Storm Sewer Shed System areas. The dataset contains locations and attributes of storm sewer systems, created as part of the DC Geographic Information System (DC GIS) for the D.C. Office of the Chief Technology Officer (OCTO) and participating D.C. government agencies. This shapefile contains all storm sewer systems including the combined sewer sheds within the DC WASA jurisdiction. There are small areas within this file, between regulators/interceptors and the outfalls, that primarily serve as storm sewer sheds. Combined flow should enter these areas only when it overflows from the interceptors.