Water resources data, Utah, water year 2004

Water-resources data for the 2004 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 156 gaging stations; stage and contents for 8 lakes and reservoirs; water quality for 16 hydrologic stations, and 29 wells; water levels for 67 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. During water year 2004, streamflows and ground-water levels in Utah again were lower than normal. This marked the sixth year (water year 1999 to 2004) of an ongoing drought in Utah and surrounding areas. Since the winter of 1998-1999, mountain snowpacks generally have been below normal statewide and have caused significant reductions in spring runoff. Additionally, soil moisture throughout the state has been very low during the drought, so a large proportion of spring melting has been absorbed into the subsurface. Utah requires above-normal precipitation (snowpack) during the winter and spring of 2004-2005 to alleviate the cumulative effects of this drought. Hydrologic conditions for Utah can vary greatly across the State because of topography, geology, changing seasonal atmospheric conditions, and changes in climatic conditions from year to year. Mountain ranges and plateaus in many parts of Utah are characterized by steep slopes, sparse vegetation, thin soils, and, in areas such as the Colorado River Basin, large expanses of bedrock and steep-walled canyons. These conditions can lead to rapid runoff and flooding that can occur any time of the year. The large valleys and basins in the western part of Utah have a fairly flat topography and are underlain with alluvial soils composed of clay, silt, sand, and gravel. Average annual precipitation in Utah ranges from about 5 inches in the Great Salt Lake Desert to about 60 inches on some of the State's highest mountains (Butler and Marsell, 1972).