Scientific Investigations Report 2005–5288
U.S. GEOLOGICAL SURVEY
Scientific Investigations Report 2005–5288
Rapid growth and development in Carson Valley is causing concern over the continued availability of water resources to sustain such growth into the future. As growth continues, ground-water pumping will increase and land presently used for agriculture will be urbanized. The effects of these changes on the valley’s water budget are uncertain, and the changes may affect flow in the Carson River which, in turn, may affect water users dependent on river flow downstream of Carson Valley (fig. 1).
In the early 1980s, the U.S. Geological Survey (USGS) estimated water-budget components for Carson Valley (Maurer, 1986). Major water-budget components include inflow from precipitation and infiltration of streamflow, and outflow from evapotranspiration (ET) and ground-water seepage to the Carson River. To address concerns over water resources in Carson Valley, a cooperative study between USGS and Douglas County, Nevada, began in February 2003 to provide updated estimates of major components of the water budget. As part of the study, reports have been published providing updated estimates of the areal distribution of annual precipitation in Carson Valley (Maurer and Halford, 2004), and updated estimates of annual and monthly streamflow tributary to the floor of Carson Valley (Maurer and others, 2004).
Since the USGS study in the early 1980s, new methods have been routinely applied to estimate ET from plants using micrometeorologic measurements (Duell, 1990; Nichols, 1992), to estimate recharge from precipitation using the chloride concentration of pore water in soil profiles (Allison and others, 1994; Phillips, 1994), and to estimate streamflow gains and losses using temperature measurements (Constantz and others, 2001; 2002). These new methods were used in Carson Valley to develop updated estimates of the major water-budget components so the effects of land- and water-use changes on the valley’s water budget can be evaluated.
This report presents and summarizes micrometeorologic, soil-chloride, and streambed-temperature data collected in Carson Valley between April 2003 and November 2004, and presents estimated rates of ET, infiltration of precipitation, and streamflow gain and loss determined using these measurements. Micrometeorologic data were collected at eight sites over various periods from mid-April 2003 through November 2004 and were used to estimate annual and monthly rates of ET from flood-irrigated alfalfa fields, flood-irrigated and nonirrigated pastures, and nonirrigated stands of native vegetation. Soil-chloride samples were collected from nine test holes as deep as 30 ft in areas of native vegetation and used to estimate rates of recharge from precipitation on the northern and eastern sides of the valley. Streambed-temperature data were collected at 37 sites on the Carson River, irrigation canals, and ditches and were used to identify locations of gaining and losing streamflow. The data also were used to estimate rates of surface-water infiltration to the water table and rates of ground-water seepage to streamflow at selected sites.
U.S.
Department of the Interior | U.S. Geological
Survey
Persistent URL: https://pubs.water.usgs.gov/sir20055288
Page Contact Information: Publications Team
Page Last Modified: Thursday, 01-Dec-2016 18:48:46 EST
