GROUND-WATER LEVEL AND PRELIMINARY WATER-QUALITY DATA IN THE DETRITAL, HUALAPAI, AND SACRAMENTO VALLEY BASINS, NORTHWESTERN ARIZONA

The Detrital, Hualapai, and Sacramento Valleys are broad, intermountain desert basins in Mohave County, northwestern Arizona, and are home to residents in the City of Kingman and several rural communities. Ground water is the primary source of water in these valleys and is essential for many economic and cultural activities. Information about ground-water levels and water quality within the valleys provide preliminary information useful to land managers and residents in the area. This study is being done in support of the Arizona Department of Water Resource's (ADWR) Rural Watershed Initiative (RWI) and is funded by ADWR and the U.S. Geological Survey (USGS).

Ground-water level changes between 1943 and 2006 and their change over time in Detrital, Hualapai, and Sacramento Valley Basins of northwestern Arizona were investigated to improve the understanding of past and current ground-water conditions in these basins. Ground-water generally moves from the mountain front toward the basin center and then along the basin axis toward the Colorado River or Lake Mead. Detrital and Hualapai Valley Basins drain towards Lake Mead and Sacramento Valley Basin drains towards the Colorado River. In Detrital Valley Basin, water levels have remained the same or have steadily increased since the 1980. Steady conditions, water-level rises, or water-level declines were found in wells within the Hualapai Valley Basin. Within the Sacramento Valley Basin, small steady rises or water-level declines were observed throughout the area during the period of record.

Water-quality data for ground water from selected wells within each of the valleys provides spatial information about the relative quality of the water. Specific-conductance data provides information about the relative salinity within the study area. Elevated concentrations of sodium and chloride were related to the dissolution of halite. Elevated concentrations of sulfate appear to be related to the dissolution of gypsum. Cation exchange may be contributing elevated concentrations of sodium and calcium. Preliminary interpretation of the apparent ground-water ages from 14C data collected in Hualapai Valley Basin indicate that the age of the ground water is recent to 9,000 years old around the edges of the basin fill and 6,500 to 18,000 years old in the center of the valley basin fill.