Water resources data for the 1988 water year for Michigan consists of records of stage, discharge, and water quality of streams; stage and contents of lakes and reservoirs; and water levels and water temperature of ground water. This report contains discharge records for 138 streamflow-gaging stations; stage only records for 15 lake-gaging stations; stage and contents for 5 lakes and reservoirs; water-quality records for 20 streamflow-gaging stations; water-level records for 51 observation wells; and water-temperature records for 5 observation wells. Also included are 52 crest-stage partial- record stations and 8 low-flow partial-record stations. Additional water data were collected at various sites not involved in the systematic data- collection program. Miscellaneous data were collected at 180 measuring sites and 10 water-quality sampling sites. These data represent that part of the National Water Data System collected by the U.S. Geological Survey and cooperating State, Local, and Federal agencies in Michigan.