The 2002 303(d) GIS files were created for reporting purposes by the SWRCB and RWQCBs. Under Section 303(d) of the 1972 Clean Water Act, states, territories and authorized tribes are required to develop a list of water quality limited segments. The waters on this list do not meet water quality standards, even after point sources of pollution have installed the minimum required levels of pollution control technology. The law requires that these jurisdictions establish priority rankings for water on the lists and develop action plans, called Total Maximum Daily Loads (TMDL), to improve water quality.
What Each Record Represents
Each record represents an impaired water body, or segment thereof, on the 2002 303(d) list, information on the number of impairments, number of sources, number of approved TMDLs, the estimated length of the impaired portion of the water body or segment and the jurisdiction of the RWQCB in which the water body occurs. A URL is provided for a U.S. Environmental Protection Agency (USEPA) web site which contains detailed information on the water body and its impairment(s). For detailed information that defines what a 303(d) list of impaired waters is visit the following EPA site. For California specific information about 303(d) listed of impaired waters visit the following SWRCB site.