Groundwater availability of the Columbia Plateau Regional Aquifer System, Washington, Oregon, and Idaho

Abstract

Although often overlooked, groundwater is increasingly important to all our lives. Groundwater is the Nation's principal reserve of freshwater. It provides one-half of our drinking water and is essential to U.S. food production while facilitating business and industry in promoting economic wellbeing. Groundwater also is an important source of water for sustaining the ecosystem health of rivers, wetlands, and estuaries throughout the country. Large-scale development of groundwater resources with accompanying declines in groundwater levels and other effects of pumping have led to concerns about the future availability of groundwater to meet all our Nation's needs. The depletion of groundwater to satisfy the country's thirst and the compounding effects of recent droughts emphasize the need for an updated status of the Nation's groundwater resources. Assessments of groundwater resources provide the science and information needed by the public and decision makers to evaluate water availability and its effects on the water supply, as well as, to manage and use the water resources responsibly. Adding to this already complex task of resource assessment is the analysis of potential future effects due to climate variability, which can further exacerbate an already challenging situation. The U.S. Geological Survey (USGS) is conducting large-scale multidisciplinary regional studies of groundwater availability, such as this study of the Columbia Plateau Regional Aquifer System. These regional studies are intended to provide citizens, communities, and natural resource managers with (1) improved information and knowledge of the status of the Nation's groundwater resources, (2) how changes in land use, water use, and climate have affected those resources, and (3) tools to forecast how these resources may change in the future. Over time, the findings from these individual regional groundwater assessments of principal aquifers can be scaled up to a national synthesis and scaled down to provide information relevant to issues of local concern. This national scale groundwater assessment directly supports the USGS National Water Census.

Landscape controls on the distribution and ecohydrology of central Oregon springs

“…Seven landscape-scale variables that describe the hydrogeologic and landscape settings of the springs and that may influence spring discharge type, discharge amount, and water chemistry were derived from other spatial datasets and summarized for each spring. These Gannett, 1984;Gonthier, 1985 Early Tertiary volcanic, volcaniclastic, and volcanic sediment deposits of the Clarno and John Day Formations 5-140 0.003-0.3 Low Gannett, 1984;Gonthier, 1985 Basalt flows of the Miocene Columbia River Basalt Group 5-900 0.3-40 Medium Ely et al, 2014;Gannett, 1984;Gonthier, 1985;Vaccaro et al, 2015 Quaternary surficial deposits 9-1,400 8-46 Medium Gannett, 1984;Gonthier, 1985;Morgan, Hinkle, & Weick, 2007 Late Tertiary volcanic, volcaniclastic, and volcanic sediment deposits of the Deschutes Formation (and their age equivalents) 20-23,000 3-680 High Gannett et al, 2001;Gannett, Lite, Risley, Pischel, & La Marche, 2017;Gonthier, 1985 Quaternary volcanic deposits of the Cascade Range and Newberry Volcano 50-74,000 1-300 High Gannett et al, 2001Gannett et al, , 2017Gates & Gannett, 1996;Manga, 1997, Saar & Manga, 2004 Note. Transmissivity and hydraulic conductivity values were estimated in the cited sources using a variety of methods including analysis of specific capacity data from well logs, published aquifer tests, and model analysis.…”

Groundwater Development Stress: Global‐Scale Indices Compared to Regional Modeling

“…The principal aquifers are in basalts of the Columbia River Basalt Group and overlying sediments (Vaccaro et al 2015). Water resources are stressed.…”

“…Groundwater levels have declined over more than 10,000 mile 2 (26,000 km 2 ; about 23% of the study area) because of groundwater pumping, with declines exceeding 300 feet (90 m) in parts of Washington and 200 feet (60 m) in Oregon (Vaccaro et al 2015). Groundwater levels have declined over more than 10,000 mile 2 (26,000 km 2 ; about 23% of the study area) because of groundwater pumping, with declines exceeding 300 feet (90 m) in parts of Washington and 200 feet (60 m) in Oregon (Vaccaro et al 2015).…”

“…The demand for water resources by people directly competes with environmental uses such as maintaining minimum stream flows and preserving fish habitat, especially for salmon. This competition is expected to increase and likely constitutes the primary constraint to groundwater development (Vaccaro et al 2015). Target or instream flows established as part of salmon recovery efforts in the Pacific Northwest greatly influence water availability.…”

“…Human activities have substantially altered the predevelopment hydrologic system through a patchwork of surface-water and groundwater irrigation. Groundwater levels have declined over more than 10,000 mile 2 (26,000 km 2 ; about 23% of the study area) because of groundwater pumping, with declines exceeding 300 feet (90 m) in parts of Washington and 200 feet (60 m) in Oregon (Vaccaro et al 2015). In contrast, surface-water irrigation has resulted in groundwater-level rises occurring over about 2400 mile 2 (6200 km 2 ; about 5% of the study area), with local water-level rises of more than 200 feet (60 m; Vaccaro et al 2015).…”