Simulation of groundwater and surface-water flow in the upper Deschutes Basin, Oregon

Field-trip guide to mafic volcanism of the Cascade Range in Central Oregon—A volcanic, tectonic, hydrologic, and geomorphic journey

“…Assuming a 400-km 2 contributing area, a mean aquifer thickness of 300 m (consistent with estimates by Gannett and Lite, 2004), a porosity of 10 percent, and an average discharge of 3.1 m 3 /s, mean residence time would be about 120 years. James and others (2000) reported a tritium content of 4.0 TU, 10 however, indicating that the Metolius River headwaters springs contain at least some component of modern water.…”

“…A 400-to 500-m 2 contributing area for the headwaters springs is consistent with topography and surface-drainage patterns in the Metolius Basin and adjacent basins. A mass balance by Gannett and Lite (2004) indicated that a flux of approximately 23 m so trees tend to stay in the stream and become covered with moss and grass. The hydrology and geomorphology of springfed channels in the Deschutes Basin was described by Whiting and Stamm (1995) and Whiting and Moog (2001).…”

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.…”

“…USGS, 2017). Along the lower 22 km of the Crooked River, there is regional groundwater discharge of about 28 m 3 s −1 , providing roughly two thirds of the mean annual flow (Gannett & Lite, 2004;Gannett, Lite, Morgan, & Collins, 2001;James, Manga, Rose, & Hudson, 2000). Above this lower reach, there are large seasonal flow variations characteristic of a run-off-dominated stream system, with mean flows ranging from 42.7 m 3 s −1 in April to 0.31 m 3 s −1 in August (USGS gage 14080500, period of record 1941-1959 prior to construction of major impoundments; Friday & Miller, 1984).…”

Springs as hydrologic refugia in a changing climate? A remote‐sensing approach

“…In some cases, oxygen and hydrogen isotopes can also indicate the general elevation at which recharge occurred, and thereby provide information about the spring source area and flow-path length (James et al 2000). Numerical groundwater models may provide information on spring source areas and travel times for large regional springs (Gannett and Lite 2004); however, they are time-intensive to develop and typically are too coarse to use for smaller springs such as those we examined. In this study, groundwater monitoring wells in the vicinity of the study area were at considerably lower elevations (~1250-1400 m) relative to the SMZs examined (all above 1300 m, and most above 1600 m), such that water-level measurements did not provide useful information on groundwater dynamics relevant to the studied springs.…”