Water discharge data for the 1987 water year for Arizona consist of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; water levels of observation wells; and quality of ground water. This report contains discharge records for 168 gaging stations, annual peaks for 22 crest-stage partial-record stations, and discharge measurements at 8 miscellaneous sites; contents only records for 9 lakes and reservoirs; stage and contents for 1 lake; elevation only for 1 streamflow station; 20 supplementary records, included with gaging-station records, consisting of monthend or monthly stage, contents, and evaporation of lakes and reservoirs, diversions, and return flows; water-quality records for 41 continous-record stations and 6 miscellaneous sites; water levels for 1,007 observation wells; and water-quality data for water from 261 wells. The data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating Federal and State Agencies in Arizona.