Storm sewer An underground conduit created to convey storm drainage into a stream channel or reservoir. If the sewer also conveys liquid waste products, then the "combined sewer" secondary site type should be used. Water Infrastructure Sites Adapted from USGS Site Types. http://wdr.water.usgs.gov/nwisgmap/help/sitetype.html ODM2 SiteType Controlled Vocabulary ODM2 Working Group A vocabulary for describing the type of a data collection Site. To some extent, these types represent the ultimate feature of interest that the site was established to measure. For example, a Stream Site was established to measure properties of a Stream.