Water resources data for the 2005 water year for Minnesota consist of records of stage, discharge, and water quality of streams; stage of lakes and reservoirs; ground-water quality; and water quality in wells. This report contains discharge records for 116 stream-gaging stations; stage for 11 lakes and reservoirs; water quality for 12 stream-gaging stations; peak flow data for 87 highflow partial-record stations, and water levels for 2 ground water observation wells. Additional water data were collected at various sites that are not part of 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 for cooperating State and Federal agencies in Minnesota.