Publications

The city of Phoenix, Arizona, relies primarily on surface water for municipal water supply. The city also maintains wells to withdraw groundwater, particularly in times of drought and reduced surface-water supply, and to recharge groundwater when excess surface water is available. As of 2023, withdrawals from the aquifer in the northeastern part of the city are a small volume of water...

The Colorado River is an important water source in the southwestern United States and northern Mexico. High concentrations of dissolved solids in the river, sourced mainly from the Upper Colorado River Basin (UCOL), cause hundreds of millions of dollars in damages annually to crops and infrastructure. Determinations of total dissolved solids (TDS) in river and tributary samples often...

The Navajo (N) aquifer is an extensive aquifer and the primary source of groundwater in the 5,400-square-mile Black Mesa area in northeastern Arizona. Water availability is an important issue in the Black Mesa area because of the arid climate, past industrial water use, and continued water requirements for municipal use by a growing population. Precipitation in the area typically ranges...

The City of Tucson water utility, Tucson Water, began releasing treated effluent into the Santa Cruz River channel near downtown Tucson in 2019. This recharge project—the Heritage Project—is intended to create a reach of consistent flow in the channel and recharge water to the aquifer. Tracking the dispersal of recharged water is important for management decisions because groundwater...

The Las Cienegas National Conservation Area was established by the Las Cienegas National Conservation Area Establishment Act of 1999 (Public Law 106–538) and is managed by the Bureau of Land Management. Located in southeastern Arizona, the conservation area contains more than 45,000 acres of rolling grassland, wetlands, and woodlands surrounded by isolated mountain ranges that are part...

Changes in the quantity of sand stored within river segments can affect aquatic and riparian habitat, archeological resources, and recreation. Since summer to fall of 2002, gaging stations on the Colorado River in Grand Canyon National Park and on its major tributaries and selected lesser tributaries have measured the mass of sand transported past each station, which allows for changes...

Resurveys of seven geomorphologic cross sections located in the Lily Park and Deerlodge Park, Colorado, reaches of the Yampa and Little Snake Rivers were conducted in October 2017. These cross sections extend from Lily Park, at the confluence of the two rivers, to Deerlodge Park within Dinosaur National Monument. Four cross sections were first surveyed in 1983 and then resurveyed in 1997...

Groundwater is an important water source in Arizona, accounting for about 41% of water use in this mostly arid-to-semiarid state in the southwestern United States, and the availability of groundwater resources in the state is a concern. To provide accessible information from depth-to-groundwater data, a series of web-based interactive maps were developed, called the Arizona Groundwater...

Breccia pipe deposits of the Grand Canyon region contain ore grade copper and uranium. Horn Creek is located near the Orphan Mine mineralized breccia pipe deposit and groundwater emerging from the bedrock in the headwaters of Horn Creek has the highest uranium concentrations in the region. Uranium decreases an order of magnitude between the groundwater at the top of the watershed and the...

The Little Colorado River alluvial aquifer near Leupp, Arizona, was investigated as a possible source of irrigation water for the Leupp and Birdsprings Chapters of the Navajo Nation. The physical, chemical, and hydraulic characteristics of the alluvial aquifer were studied using geophysical surveys, installation of observation wells, water-level measurements, chemical analyses...

Study region: This study focuses on the Colorado River watershed in the area along the South Rim of the Grand Canyon. Study focus: This study utilizes anthropogenic chemical tracers to investigate the fate of treated wastewater effluent discharged within Grand Canyon National Park. Anthropogenic chemical tracers were used to discern preferential structurally controlled pathways in a...

The Grand Canyon in northern Arizona is an international tourist destination, a home or sacred place to many Native Americans, and hosts some of the highest-grade uranium deposits in the United States. Although potential contamination of water resources by uranium from mining activities is a concern, other elements commonly associated with these uranium deposits may pose a greater risk...