G.E. Kues 1987 The Albuquerque-Belen Basin is in north-central New Mexico and is approximately 100 mi long and 25 to 40 mi wide. The only perennial stream in the area, the southward-flowing Rio Grande, approximately bisects the basin. Groundwater is the only source used to obtain drinking-water supplies. The basin 's population increased more than 100% from 1960 to 1980. In 1980, 72% of the population was concentrated in the north-central part of the basin in and around the city of Albuquerque. Increases in population caused increases in water demand and groundwater pumpage. A network of wells was selected between April 1982 and September 1983 to monitor changes in groundwater levels. (USGS) application/pdf 10.3133/ofr87116 en U.S. Geological Survey, Ground-water-level data for the Albuquerque-Belen Basin, New Mexico, through water year 1985 reports