Preliminary ground-water level and water-quality data in the Detrital,

Hualapai, and Sacramento Valley Basins

1Margot Truini, and 2David W. Anning,

The Detrital, , and Sacramento Valleys are broad, intermountain desert

basins in Mohave County, northwestern , 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. Management of

the available ground-water resources in these valleys guided by a comprehensive

scientific understanding can help the growing communities to meet their needs in a

sustainable manner. 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. The potentiometric surface for ground water in the basin-fill aquifer of each basin is generally parallel to land surface elevations. Consequently, ground-water generally moves from the mountain front toward the basin center and then along the basin axis toward the or . Detrital and Hualapai Valley Basins drain towards Lake Mead and Sacramento Valley Basin drains towards the Colorado River. In

Detrital Valley Basin, water levels generally have remained the same or have steadily increased since the 1980. Steady conditions, water-level rises, or water-level declines

were found in wells penetrating the basin-fill aquifer in areas 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. Dissolved-solids and specific-conductance data provides information about the relative salinity within the study area. Ground-water from some areas had elevated concentrations of sodium and chloride 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. Ground-water in the hard rock aquifers was

generally higher in specific conductance and dissolved solids than water from the Basin-

Fill aquifers. Preliminary interpretation of the relative 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.

1 Margot Truini, U.S. Geological Survey, Flagstaff Science Center, 2255 N. Gemini Drive, Flagstaff, AZ 86001, Ph: 928-556-3025, fax: 928-556-7112, [email protected]

2David W. Anning, U.S. Geological Survey, Flagstaff Science Center, 2255 N. Gemini Drive, Flagstaff, AZ 86001, Ph: 928-556-7139, Fax: 928-556-7112, [email protected]