Water-resources data for the 2005 water year for Utah consist of records of stage, discharge, and water quality of streams; stage and contents of lakes and reservoirs; and water levels and water quality of ground water. This report contains discharge records for 165 gaging stations; stage and contents for 8 lakes and reservoirs; water quality for 22 hydrologic stations, and 57 wells; water levels for 65 observation wells; and precipitation for 3 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 collected by the U.S. Geological Survey and cooperating State and Federal agencies in Utah.