The U.S. Geological Survey, in cooperation with the New Mexico Interstate Stream Commission, developed a geodatabase compendium (hereinafter referred to as the 'geodatabase') of available water-resources data for the reach of the Rio Grande from Rio Arriba-Sandoval County line, New Mexico, to Presidio, Texas. Since 1889, a wealth of water-resources data has been collected in the Rio Grande Basin from Rio Arriba-Sandoval County line, New Mexico, to Presidio, Texas, for a variety of purposes. Collecting agencies, researchers, and organizations have included the U.S. Geological Survey, Bureau of Reclamation, International Boundary and Water Commission, State agencies, irrigation districts, municipal water utilities, universities, and other entities. About 1,750 data records were recently (2010) evaluated to enhance their usability by compiling them into a single geospatial relational database (geodatabase). This report is intended as a user's manual and administration guide for the geodatabase. All data available, including water quality, water level, and discharge data (both instantaneous and daily) from January 1, 1889, through December 17, 2009, were compiled for the study area. A flexible and efficient geodatabase design was used, enhancing the ability of the geodatabase to handle data from diverse sources and helping to ensure sustainability of the geodatabase with long-term maintenance. Geodatabase tables include daily data values, site locations and information, sample event information, and parameters, as well as data sources and collecting agencies. The end products of this effort are a comprehensive water-resources geodatabase that enables the visualization of primary sampling sites for surface discharges, groundwater elevations, and water-quality and associated data for the study area. In addition, repeatable data processing scripts, Structured Query Language queries for loading prepared data sources, and a detailed process for refreshing all data in the compendium have been developed. The geodatabase functionality allows users to explore spatial characteristics of the data, conduct spatial analyses, and pose questions to the geodatabase in the form of queries. Users can also customize and extend the geodatabase, combine it with other databases, or use the geodatabase design for other water-resources applications.