Water Availability and Usage on the New Mexico/Mexico Border

Article excerpt


New Mexico is one of four U.S. states that share a border with Mexico. The other states are California. Arizona, and Texas. Population along the U.S./Mexico border is increasing exponentially. Population growth of 50 percent along the border by 2020 is, short of war, natural disaster, or some incredible unforeseen change in patterns of birth and death, a certainty (Peach & Williams, 2001). The border population could grow from about 10.6 million in 1995 to more than 24 million by 2020. On the Mexico side of the border, population could grow from 4.8 million to almost 13.5 million, with today's metropolitan areas becoming very large cities (Peach & Williams, 2001). The population growth rate is 35 percent along the U.S./Mexico border, in contrast with 10 percent in other parts of the United States. Rising temperatures, an arid climate, and economic and social development add to demands on water supplies. As a result, there is an increasing need to explore the availability and usage of water for current and projected needs.

Sources of Water in New Mexico


Groundwater is a highly significant part of water resources in New Mexico. Approximately 90 percent of the population depends on groundwater for its drinking water, and nearly one half of the total water used for all purposes in the state is groundwater. In addition, in many locations, groundwater is the only available water supply (NMED, 2001a). The magnitude of groundwater supplies in the state is estimated to be 20 billion acre-feet. Out of this amount, an estimated three billion acre-feet of fresh water and 1.4 billion acre-feet of slightly salinated water are recoverable (NMED, 2000b). In some areas with significant

ground water use, groundwater levels have already declined because of withdrawal rates in excess of recharge rates.

New Mexico's hydrogeology is highly variable and complex, and the availability of groundwater also varies from place to place. Sedimentary deposits (mainly sandstone, limestone, or unconsolidated sand and gravel) are the most productive aquifers. Valley-fill aquifers of major importance occur along the Rio Grande, the Rio Chama, the San Juan, and the Pecos rivers. These aquifers are typically less than 200 feet thick and commonly provide water containing less than 1,000 milligrams per liter of total dissolved solids. A major basin-fill aquifer occurs in the Rio Grande Valley, where basin-fill deposits attain thickness up to 20,000 feet. This aquifer provides the source of water for Albuquerque and is a partial source for Santa Fe (NMED, 2000b). The Rio Grande Basin is bounded along the eastern side by mountains. Total mountain-front recharge along the eastern side of the Middle Rio Grande Basin has been estimated to be about 11,000 acre-feet per year by the chloride-balance method and about 36,000 and 38,000 acre-feet per year by two water-yield regression equations. Mountain-front recharge ranges from 0.7 to 15 percent of total annual precipitation in the sub-areas (Anderholm, 2000). At present, groundwater in the Rio Grande aquifer is rapidly dwindling.

Other aquifer systems include the Roswell Basin aquifer system, which extends through an area of about 12,000 square miles in southeastern New Mexico; the Pecos River Basin alluvial aquifer system, which yields large quantities of water mostly to irrigation wells: the Ogallala aquifer, which includes Clovis and Portales; and the Mimbres Basin near Deming, in the southern part of the state (U.S. Geological Survey, 2001).

Approximately 2,500 public-supply water wells serve 97,000 New Mexico households, while approximately 266,000 individual New Mexico residents are served by privately owned individual wells (National Ground Water Association, 2001).

Another important groundwater source is the Hueco Bolson, from which both El Paso, Texas, and Ciudad Juarez in Chihuahua, Mexico, pump water. …