This dataset sums the CAUSES for listing a waterbody on the US EPA's 303d list by HUC 10 watershed. The line (streams) and polygon (ponds, lakes, reservoirs, etc.) GIS was obtained from the California State Water Quality Control Board and contains all streams listed on the 303d list. These GIS layers were joined to a table (also from the California State Water Quality Control Board) that lists all impaired water bodies, the pollutant for which they are listed, and the potential CAUSE of that...