Water-resources data for the 1993 water year for California consist of records of stage, discharge, and water quality of streams, stage and contents in lakes and reservoirs, and water levels and water quality in wells. Volume 4 contains discharge records for 190 gaging stations, stage and contents for 41 lakes and reservoirs, precipitation data for 3 stations, and water quality for 8 stations. Also included are two low-flow partialrecord stations. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in California.