Water resources data for the 1987 water year for Louisiana consist of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels and water quality of ground water. This report contains records for water discharge at 63 gaging stations; stage only for 19 gaging stations and 7 lakes; water quality for 48 surface-water stations (including 19 gaging stations), 6 lakes, and 77 wells; and water levels for 346 observation wells. Also included are data for 103 crest-stage and flood-profile partial-record stations. Additional water data were collected at various sites not involved in the systematic data-collection program, and are published as miscellaneous measurements. 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 Louisiana.