The Albuquerque, New Mexico, area has two principal sources of water: groundwater from the Santa Fe Group aquifer system and surface water from the San Juan-Chama Diversion Project. From 1960 to 2002, groundwater withdrawals from the Santa Fe Group aquifer system have caused water levels to decline more than 120 feet in some places within the Albuquerque area, resulting in a great deal of interest in quantifying the river-aquifer interaction associated with the Rio Grande. In 2003, the U.S. Geological Survey in cooperation with the Bureau of Reclamation, the Middle Rio Grande Endangered Species Collaborative Program, and the U.S. Army Corps of Engineers began a detailed characterization of the hydrogeology of the Rio Grande riparian corridor in the Albuquerque, New Mexico, area to provide hydrologic data and enhance the understanding of rates of water leakage from the Rio Grande to the alluvial aquifer, groundwater flow through the aquifer, and discharge of water from the aquifer to the riverside drains. A simple conceptual model of flow indicates that the groundwater table gently slopes from the Rio Grande towards riverside drains and the outer boundaries of the inner valley. Water infiltrating from the Rio Grande initially moves vertically below the river, but, as flow spreads farther into the Rio Grande inner valley alluvial aquifer, flow becomes primarily horizontal. The slope of the water-table surface may Groundwater Hydrology and Estimation of Horizontal Groundwater Flux from the Rio Grande at Selected Locations Suzuki-Stallman method for the Montaño East transects of 0.34 feet per day. Assuming the Albuquerque Riverside Drain intercepted all this flow, the q slug or q heat fluxes would only account for 18 to 21 percent, respectively, of the increase in flow in the drain. The comparison of these results with those of previous investigations suggests that calculated flux through the Rio Grande inner valley alluvial aquifer is strongly scale dependent and that the thickness of aquifer through which river water flows may be greater than indicated by the vertical temperature profiles. Purpose and Scope This report documents the collection and analysis of geologic, groundwater, and surface-water data from the inner valley of the Albuquerque area. The data are used to describe the groundwater hydrology of the Rio Grande inner valley alluvial aquifer and to estimate horizontal groundwater flux from the Rio Grande to the riverside drains. The report presents a simple conceptual model of groundwater flow and a comparison of groundwater-flux results derived from two methods: Darcy's law and the Suzuki-Stallman solution of heat transport in an aquifer. Data used in this report were collected from 10 transects located near the Paseo del Norte, Montaño, Barelas, Rio Bravo, and I-25 bridges (fig. 1). Groundwater and surface-water levels, temperature and slug-test data, seepage measurements, and core samples were collected from December 2003 to early 2009.
