Images

Graphs showing water-year total precipitation and air temperatures in the Lower Colorado River Basin from 1896 to 2019, units modified from millimeters to inches of precipitation and from degrees Celsius to degrees Fahrenheit from: Tillman, F.D., Gangopadhyay, S., and Pruitt, T., 2020, Trends in recent historical and projected climate data for the Colorado River Bas

USGS Hydrographer, Janice Talley, collecting surface-water water-quality samples for a salinity monitoring project along the Lower Gila River, December 2024.

USGS Hydrologist, Jessica Anderson taking field readings for salinity monitoring along the Gila River, December 2024

USGS Hydrographer, Janice Talley, collecting a water-quality sample at Hidden Lake along the Lower Gila River, December 2024

USGS Hydrographer, Janice Talley, collecting surface-water water-quality samples for a salinity monitoring project along the Lower Gila River, December 2024

Graphs showing mean annual precipitation and air temperature trends in the Lower Colorado River Basin, 1896-2019, published in: Tillman, F.D., Gangopadhyay, S., and Pruitt, T., 2020, Trends in recent historical and projected climate data for the Colorado River Basin and potential effects on groundwater availability: U.S.

Zach Harrison collects a water quality sample at Willow Spring, AZ. Photo courtesy of Kat Cooney, AZ Water Science Center.

Kat Cooney of the Arizona Water Science Center (AZWSC) runs an alkalinity titration in a mobile lab. Photo courtesy of Kat Cooney, USGS.

Graphs showing trends in atmospheric precipitation and air temperature in the Lower Colorado River Basin, 1896-2019

Kat Cooney stands in front of an outreach table on the Flagstaff USGS campus during the USGS Open House, Nov. 2023.

USGS Hydrologist, Jessica Anderson, measuring streamflow along the Lower Gila River at Tres Rios Wetlands, March 2023

USGS Hydrologist, Sarah Shepherd, collecting a water-quality sample at Tres Rios Wetlands along the Gila River, March 2023

The USGS Southwest Gravity Program carries out gravity projects for aquifer-storage monitoring and geologic modeling in California, Arizona, and New Mexico. This map shows the location of 24 projects carried out since 2010.

As generalized in this image, a gravity measurement is sensitive to a cone-shaped region of the subsurface—as depth increases, the sensitivity to individual water molecules decreases, but the region of sensitivity expands.

Map of study area and location of data collection sites in the Yuma, Arizona, area between Imperial Dam and the southerly international boundary between the United States and Mexico,

Line graph showing modeled continuous dissolved-solids concentration and sampled dissolved-solids concentration at station 09522005 (Colorado River below Cooper wasteway near Yuma, Arizona) and streamflow at station 09522000 (Colorado River at NIB, above Morelos Dam, Arizona) from January 2017 to March 2019.

Map of maximum uranium concentration at 206 spring and well sites in the Grand Canyon region.

Nick Paretti, Arizona Water Science Center (AZWSC), measures water flow at a tributary to the Colorado River in Grand Canyon. Photo courtesy of Kat Cooney, USGS, AZWSC.

This is an image of an extensometer well part of the Tucson Extensometer Well Network. This well is located in Avra Valley, AZ.

This report includes five chapters. Chapter A (Mason, Knight, and others, 2020) is a summary of this multichapter volume and briefly describes the study area. Chapter B (Mason, Bills, and Macy, 2020) describes the geology and hydrology of the Truxton basin and Hualapai Plateau.

Flooding at Vekol Wash today, south of Phoenix, following remnant rains from Hurricane Rosa.