Faunt, C.C. 2012 vector digital data Reston, VA U.S. Geological Survey https://water.usgs.gov/lookup/getspatial?pp1766_1961_wt_contours Faunt, Claudia C. 2009 Professional Paper 1766 Reston, VA U.S. Geological Survey https://pubs.usgs.gov/pp/1766/PP_1766.pdf This digital dataset defines the spring 1961 water-table altitude for the California's Central Valley. It was used to initiate the water-level altitudes for the upper zones of the transient hydrologic model of the Central Valley flow system. The Central Valley encompasses an approximate 50,000 square-kilometer region of California. The complex hydrologic system of the Central Valley is simulated using the USGS numerical modeling code MODFLOW-FMP (Schmid and others, 2009). This simulation is referred to here as the Central Valley Hydrologic Model (CVHM) (Faunt, 2009). Utilizing MODFLOW-FMP, the CVHM simulates groundwater and surface-water flow, irrigated agriculture, land subsidence, and other key processes in the Central Valley on a monthly basis from 1961-2003. The starting heads are based on the water-table and potentiometric surface developed by Williamson and others (1989). Maps of the spring 1961 water-table and hydraulic head in the lower pumped zone are shown in Figure 31 of Williamson and others (1989). The CVHM is the most recent regional-scale model of the Central Valley developed by the U.S. Geological Survey (USGS).The CVHM was developed as part of the USGS Groundwater Resources Program (Faunt, 2009. See "Foreword", Chapter A, page iii, for details). The spring 1961 water-table altitude contours were used to develop input files for MODFLOW-FMP, the USGS 3-dimensional finite-difference code used to simulate flow in the CVHM. The CVHM is a tool that accounts for integrated, variable water-supply and -demand, and simulates surface-water and groundwater-flow across the entire Central Valley system. The spring 1961 water-table altitude contours dataset is one of many layers in a geospatial database supporting the USGS Central Valley Groundwater Availability Project. Regional groundwater availability studies quantify current groundwater resources, evaluate how those resources have changed through time, and provide tools that decision makers can use to predict system responses to future development and climate variability and change. To provide information to stakeholders addressing these issues, the USGS made a detailed assessment of groundwater availability of the Central Valley aquifer system, which includes: (1) the present status of groundwater resources; (2) characterization of how these resources have changed over time; and (3) tools to assess system responses to stresses from future human uses and climate variability and change. This effort builds on previous investigations, such as the USGS Central Valley Regional Aquifer System and Analysis (CV-RASA) project and several other groundwater studies in the Valley completed by Federal, State and local agencies at various scales. Data from these previous studies were the foundation of the Central Valley geospatial database. These and other data were reexamined through a series of regional-scale hydrologic investigations to provide updated and spatially consistent interpretations for the Central Valley Groundwater Availability study. In some cases, new data were collected to augment existing information. Data compiled from the studies include geology (in particular, borehole lithology and the extent and thickness of the Corcoran Clay Member of the Tulare Formation), topography, remote sensing, climate (precipitation and temperature), geophysics, vegetation and land use, vegetation properties, hydrology (stream network and flows), groundwater levels, subsidence, chemistry, and soils. Digital elevation models, geologic maps, borehole information, cross sections, and other 3-dimensional models were used to develop the texture model which represents the properties and geometry of the Central Valley alluvial deposits. The resulting geospatial database supports characterization and conceptualization of the Central Valley hydrologic system between 1961 and 2003, construction of 3-dimensional hydrogeologic framework and hydrologic flow models, and visualization of analysis and model results. 1961 publication date Complete None planned -122.549364 -118.695195 40.326483 34.961280 ISO 19115 Topic Category inlandWaters geoscientificinformation American Geological Institute Glossary of Geology (http://glossary.agiweb.org/dbtw-wpd/glossary/search.aspx) model hydrogeology hydrology groundwater water table USGS Thesaurus inlandWaters Central Valley Aquifer Central Valley Hydrologic Model Flow Model CVHM Texture Model CV-RASA Groundwater Availability of the Central Valley Aquifer discretization USGS Metadata Identifier USGS:c6ec4532-61b9-44b9-b672-3d71d8cedde2 U.S. Board of Geographic Names (BGN) and Geographic Names Information System (GNIS) California Central Valley Trinity County Shasta County Tehama County Humboldt County Butte County Mendocino County Glenn County Yuba County Lake County Nevada County Colusa County Sutter County Placer County El Dorado County Yolo County Sonoma County Napa County Sacramento County Amador County Solano County Calaveras County Tuolumne County San Joaquin County Contra Costa County Stanislaus County Alameda County Mariposa County Madera County Merced County Fresno County Santa Clara County San Benito County Monterey County Tulare County Kings County Kern County San Luis Obispo County Santa Barbara County Ventura County Sacramento Valley San Joaquin Valley Central Valley, California None. Data have been checked to ensure the accuracy of the data. If any errors are detected, please notify the originating office. The U.S. Geological Survey strongly recommends that careful attention be paid to the metadata file associated with these data. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Acknowledgement of the U.S. Geological Survey would be appreciated in products derived from these data. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this Federal Geographic Data Committee-compliant metadata file is intended to document the dataset in nonproprietary form, as well as in ArcGIS format, this metadata file may include some ArcGIS-specific terminology. Claudia C. Faunt U.S. Geological Survey Hydrologist mailing and physical address

4165 Spruance Road, Suite 200

San Diego CA 92101 USA (619) 225-6142 (619) 225-6101 ccfaunt@usgs.gov https://water.usgs.gov/GIS/browse/pp1766_1961_wt_contours.png Illlustration of data set png Spatial datasets supporting the Central Valley Groundwater Availability project were developed primarily by the U.S. Geological Survey's (USGS) Groundwater Resources Program. This program is conducting large-scale multidisciplinary regional studies of groundwater availability. The U.S. Bureau of Reclamation is supporting the updating of the Central Valley datasets and their documentation and release. Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.3.1.3500 Schmid, Wolfgang Hanson, R. T. Maddock, Thomas, III Leake, S. A. 2006 Techniques and Methods 6-A17 Sacramento, CA USGS California Water Science Center https://pubs.usgs.gov/tm/2006/tm6A17/ Attributes added by the GIS and the data-set author were checked by inspection using a GIS. In addition, attributes were checked and evaluated as part of the review process associated with the publication of the source report. Lines forming polygons join at endpoints to completely enclose defined areas. Lines not enclosing areas do not intersect. No duplicate line features exist and all nodes are represented by a single coordinate pair which indicates the beginning or end of a line. All vertices that define the shape of the line are represented by a unique coordinate pair. The line features in this dataset are computer-generated and represent the water table in the Central Valley Hydrologic Model. The dataset is complete and is not anticipated to change. Horizontal positional accuracy of line features in the dataset was tested by visually comparing them to digital source maps by using a GIS system. Faunt, C. C. 2009 document U.S. Geological Survey Professional Paper 2009-1766 Reston, Virginia U.S. Geological Survey https://pubs.usgs.gov/pp/1766/PP_1766.pdf Faunt, C.C. 2009 U.S. Geological Survey Professional Paper 2009-1766 Reston, Virginia U.S. Geological Survey online 2009 publication date Faunt and others (2009) water table contour lines Williamson, A. K. Prudic, D. E. Swain, L. A. 1989 Professional Paper 1401-D Reston, VA U.S. Geological Survey Figure 31A https://pubs.usgs.gov/pp/1401d/report.pdf online 2009 publication date Williamson and others (1989) Linework sourced from PP 1401-D, Figure 31A - Spring 1961 water table altitude in the lower pumped zone A figure showing the contour lines was scanned into a digital image format. It was then georeferenced and a Geographic Information System (GIS) was used to trace/digitize the contour lines into a dataset, shapefile format. Each contour line was assigned an attribute value for hydraulic head (in feet). Williamson and others (1989) 04012005 08303600 Faunt, C.C. USGS Hydrologist mailing and physical address

4165 Spruance Road, Suite 200

San Diego CA 92101 USA (619) 225-6142 ccfaunt@usgs.gov Central Valley, comprised of the Sacramento Valley on the north and the San Joaquin Valley on the south, located in the state of California. Vector String 69 Albers Conical Equal Area 29.500000 45.500000 -120.000000 23.000000 0.000000 0.000000 coordinate pair 100 100 meters North American Datum of 1983 Geodetic Reference System 80 6378137.000000 298.257222 1961_wt_contours Contour data of the Central Valley water table, 1961 dataset originator FID Internal feature number. ESRI Sequential unique whole numbers that are automatically generated. Shape Feature geometry. ESRI Coordinates defining the features. WL_1961SPR Contour value of altitude of water-table. Contour interval is 40 feet from 0 to 400 feet and 100 feet above 400 feet. dataset originator 0 700 Feet above NGVD 29. Datum is sea level. 40. The smallest unit increment to which an attribute value is measured There are 69 records in this shapefile. It has two attributes that are generated by the GIS (FID and Shape) for internal software purposes. The remaining attribute was assigned by the author (Citation Originator) to define Spring 1961 water table altitude. This data was used for analysis and for developing input files for the CVHM. none U.S. Geological Survey Michael Ierardi IT Specialist mailing and physical

445 National Center

Reston Virginia 20192 USA 1-888-275-8747 (1-888-ASK-USGS) mierardi@usgs.gov Downloadable Data Digital geospatial datasets for the textural model and numerical model of the hydrogeologic landscape and groundwater flow in California's Central Valley. Although these data have been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of these data, software, or related materials. The use of firm, trade, or brand names in this report is for identification purposes only and does not constitute endorsement by the U.S. Geological Survey. The names mentioned in this document may be trademarks or registered trademarks of their respective trademark owners. SHP ESRI Shapefile 0.028 https://water.usgs.gov/GIS/dsdl/pp1766_1961_wt_contours.zip None. This dataset is provided by the USGS as a public service. 2011 20201117 U.S. Geological Survey Michael Ierardi IT Specialist mailing and physical address

445 National Center

Reston VA 20192 USA 1-888-275-8747 (1-888-ASK-USGS) mierardi@usgs.gov FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998