Sources of water to the Rio Grande upstream from San Marcial, New Mexico

The Rio Grande watershed is a complex hydrologic system that includes numerous tributaries, inflow from transmountain diversions, irrigation diversions, agricultural return lows, reservoirs, and ground-water inflows and outflows. Many people depend on and are affected by the Rio Grande, which is the largest river of the surface-water system draining the Rio Grande watershed. To provide information to further the understanding of the Rio Grande surface-water system, the U.S. Geological Survey, in cooperation with the City of Albuquerque, evaluated streamflow data computed by the U.S. Geological Survey at 60 streamflowgaging stations. This fact sheet examines the sources of water to the Rio Grande and the "water balance" of the Rio Grande surface-water system upstream from San Marcial, New Mexico, by comparing the mean annual discharge (streamflow) at different stations.