Water resources data for the 1979 water year for Arkansas consist of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels of wells. This report contains discharge records for 66 gaging stations; stage and contents for four lakes and reservoirs; water quality for 151 gaging stations, 51 partial-record stations, seven lakes, and five wells; and water levels for 83 observation wells. Also included are data for 125 crest-stage partial-record stations. Additional water data were collected at various sites, 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 and cooperating State and Federal agencies in Arkansas.