Water-resources data for the 2001 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 2 contains discharge records for 128 gaging stations, stage and contents for 6 lakes and reservoirs, gage-height records for 8 stations, water quality for 43 streamflow-gaging stations and 2 partial-record stations, and precipitation data for 1 station. Also included are data for 1 low-flow partial-record station, and 8 miscellaneous-measurement 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.