Arizona Water Science Center
Conceptualizing ecological responses to dam removal: If you remove it, what's to come?
One of the desired outcomes of dam decommissioning and removal is the recovery of aquatic and riparian ecosystems. To investigate this common objective, we synthesized information from empirical studies and ecological theory into conceptual models that depict key physical and biological links driving ecological responses to removing dams. We...Bellmore, J. Ryan; Pess, George R.; Duda, Jeffrey J.; O'Connor, Jim E.; East, Amy E.; Foley, Melissa M.; Wilcox, Andrew C.; Major, Jon J.; Shafroth, Patrick B.; Morley, Sarah A.; Magirl, Christopher S.; Anderson, Chauncey W.; Evans, James E.; Torgersen, Christian E.; Craig, Laura S.
Groundwater, surface-water, and water-chemistry data, Black Mesa area, northeastern Arizona—2015–2016
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. Availability of water is an important issue in the Black Mesa area because of continued water requirements for industrial and municipal use by a growing population and because of the arid climate....Mason, Jon P.; Macy, Jamie P.
Filtering of cyclic period infiltration in a layered vadose zone: 1. Approximation of damping and time lags
Infiltration and downward percolation of water in the vadose zone are important processes that can define the availability of water resources. We present an approach that provides insight into how periodic infiltration forcings at the land surface filter in a layered vadose zone in terms of changes in the timing and magnitude of hydrologic...Dickinson, Jesse E.; Ferre, T.P.A
Groundwater-storage change and land-surface elevation change in Tucson Basin and Avra Valley, south-central Arizona—2003–2016
The U.S. Geological Survey monitors groundwater-storage change and land-surface elevation change caused by groundwater withdrawal in Tucson Basin and Avra Valley—the two most populated alluvial basins within the Tucson Active Management Area. The Tucson Active Management Area is one of five active management areas in Arizona established by the...Carruth, Robert L.; Kahler, Libby M.; Conway, Brian D.
Filtering of periodic infiltration in a layered vadose zone: 2. Applications and a freeware screening tool
We have developed a screening tool to visualize and conceptualize the filtering properties of a layered vadose zone. Climate projections indicate that rainfall timing and magnitude may change and impact groundwater resources. This increases the importance of understanding how the vadose zone filters infiltration variability and ultimately affects...Dickinson, Jesse E.; Ferre, T.P.A
Findings and lessons learned from the assessment of the Mexico-United States transboundary San Pedro and Santa Cruz aquifers: The utility of social science in applied hydrologic research
Study RegionThis study region encompasses the Transboundary San Pedro and Santa Cruz aquifers which are shared between the states of Sonora (Mexico) and Arizona (US). Special regional considerations include a semi-arid climate, basin-fill aquifers with predominantly montane recharge areas, economic drivers in the mining, trade, and military...Callegary, James B.; Megdal, Sharon B.; Tapia Villaseñor, Elia María; Petersen-Perlman, Jacob D.; Minjárez Sosa, Ismael; Monreal, R.; Gray, F.; Grijalva Noriega, Francisco
Assessment of environmental flows in the middle Verde River watershed, Arizona
This report summarizes analyses of middle Verde River watershed environmental flows detailed in U.S. Geological Survey Scientific Investigations Report 2017-5100, “Preliminary synthesis and assessment of environmental flows in the middle Verde River watershed, Arizona," by N.V. Paretti, A.M.D. Brasher, S.L. Pearlstein, D.M. Skow, B. Gungle, and B....Gungle, Bruce W.; Paretti, Nicholas V.
Changes in Earth’s gravity reveal changes in groundwater storage
Changes in the amount of water stored in underground aquifers cause small changes in Earth’s gravitational field. The U.S. Geological Survey’s Southwest Gravity Program has developed methods for measuring terrestrial gravity changes with part-per-billion precision. The measurements allow scientists to map changes in groundwater storage and to...Kennedy, Jeffrey R.
Conceptual and numerical models of dissolved solids in the Colorado River, Hoover Dam to Imperial Dam, and Parker Dam to Imperial Dam, Arizona, California, and Nevada
Conceptual and numerical models were developed to understand and simulate monthly flow-weighted dissolved-solids concentrations in the Colorado River at Imperial Dam. The ability to simulate dissolved-solids concentrations at this location will help the Bureau of Reclamation satisfy the binational agreement on the volume and salinity of Colorado...Anning, David W.; Coes, Alissa L.; Mason, Jon P.
Effect of spatial and temporal scale on simulated groundwater recharge investigations
Hydrologic model input datasets such as climate, land use, elevation, soil, and geology information are available in a range of scales for use in water resources investigations. Smaller spatial and temporal scale input data allow groundwater recharge models to simulate more physically realistic processes and presumably result in more accurate...Tillman, Fred; Pruitt, Tom; Gangopadhyay, Subhrendu
Brackish groundwater and its potential as a resource in the southwestern United States
Secure, reliable, and sustainable water resources are fundamental to food production, energy independence, and the health of humans and ecosystems. But the large-scale development of fresh groundwater resources has stressed aquifers in some areas, causing declines in the amount of groundwater in storage and decreases in discharge to surface-water...Anning, David W.; Beisner, Kimberly R.; Paul, Angela P.; Stanton, Jennifer S.; Thiros, Susan A.
Geochemical characterization and modeling of regional groundwater contributing to the Verde River, Arizona between Mormon Pocket and the USGS Clarkdale gage
We use synoptic surveys of stream discharge, stable isotopes, and dissolved noble gases to identify the source of groundwater discharge to the Verde River in central Arizona. The Verde River more than doubles in discharge in Mormon Pocket over a 1.4 km distance that includes three discrete locations of visible spring input to the river and other...Beisner, Kimberly R.; Gardner, W. Payton; Hunt, Andrew G.