Frequently Asked Questions About Water


Where does our drinking water come from?

Drinking water comes from two basics sources: surface water and ground water. These water sources are linked through the hydrologic cycle.

Initially, all of New Mexico’s water comes from precipitation, and the principal constraint on our water supply is climate. Most of New Mexico is a desert. A desert is defined as a region with a mean annual precipitation of 10 inches or less, and so devoid of vegetation as to be incapable of supporting any considerable population. Precipitation in New Mexico ranges from 6.7 inches at Shiprock to a maximum of 26.2 inches at Cloudcroft, but much of New Mexico receives less than 10 inches of water per year. Most of the precipitation that falls evaporates within a short time of reaching the ground (or sometimes before). Of the precipitation that reaches land without evaporating, much is taken up and used by plants (called transpiration). The rest either flows across the land surface into rivers and streams, or percolates into the ground, where it recharges underground aquifers. The portion of New Mexico where precipitation exceeds the combination of evaporation and transpiration (called evapotranspiration) is limited to a few areas of high elevation during the cool months of the year.

Surface water refers to all water located on the surface of the land—rivers, lakes and streams. New Mexico’s surface water supply originates as rain or melting snow, but 97 percent of that water evaporates or is transpired by plants.

Most of New Mexico’s fresh water is stored as groundwater in aquifers below the land surface, where it occupies small open spaces between grains of sand or gravel and small cracks or fractures in rock. These cracks and void spaces are referred to as the porosity of the rock or sediment. All rocks that underlie the earth’s surface are classified as either aquifers or confining beds (also known as aquitards). An aquifer is a saturated rock unit or geologic formation that yields significant quantities of water to wells and springs. A confining bed (or aquitard) is a saturated geologic unit of less permeable material that is incapable of transmitting significant quantities of water, thus restricting the movement of ground water either into or out of adjacent aquifers. Ground water occurs in aquifers under two different conditions. In places where water only partially fills an aquifer, the upper surface of the water table is open to the atmosphere and is free to rise and fall in response to atmospheric pressure and changes in aquifer storage. The water in these aquifers is said to be unconfined, and the aquifers are referred to as unconfined aquifers or water-table aquifers. Where water completely fills an aquifer that is overlain by a confining bed, the water in the aquifer is confined under pressure and the aquifer is referred to as a confined or artesian aquifer.

Further information about New Mexico’s water resources can be found in:
Johnson, P., 2003, A primer on water: ground water, surface water, and its development, in Johnson, P.S., Land, L.A., Price, L.G., and Titus, F., (eds.), Water Resources of the Lower Pecos Region, New Mexico: Science, Policy, and a Look to the Future: New Mexico Bureau of Geology and Mineral Resources Decision-Makers Field Conference, p. 14-19.

Another reference that provides specific hydrologic information for the state of New Mexico is:
Stone, W.J., 2001, Our water resources: An overview for New Mexicans: New Mexico Bureau of Geology and Mineral Resources Information Series 1, 37 pp. (link to our publications)

Other links to general hydrological information include:
What is the depth to groundwater in my area?

The best source of average depth to groundwater information in the state of New Mexico is the W.A.T.E.R.S. database.

This database can be searched using either Township-Range-section, State Plane, or UTM coordinate location information.

Publications about water levels in particular areas in New Mexico can be obtained from the U.S. Geological Survey.

Click the Publications Warehouse button, and type the key words, New Mexico water + your area of interest.

The U.S. Geological Survey has published water table levels for the Albuquerque area as of 2002 (see chapter 4, p. 50).

Are there New Mexico Bureau of Geology and Mineral Resources publications that have depth-to-ground water information?

Yes, although the data are somewhat out-of-date on many of our older publications. See our Aquifer Mapping Program page for the results of more current work. Another useful source of current depth-to-groundwater information is the WATERS database from the Office of the New Mexico State Engineer.

How much has the depth to groundwater in my area changed in the last few years?

The U.S. Geological Survey monitors the water table level in 3161 wells in the state of New Mexico. These data should be used with caution because water table in shallow wells tapping into an alluvial aquifer may fluctuate dramatically in response to rain or snowmelt events.

Bexfield and Anderholm (2002) published a map showing the changes in depth to groundwater in the Albuquerque area.

Bexfield, L. M.and Anderholm, S. K., 2002, Estimated water-level declines in the Santa Fe Group aquifer system in the Albuquerque area, central New Mexico, predevelopment to 2002, U.S. Geological Survey Water Resources Investigation WRI 2002-4233, map, on sheet 59 x 88 cm.

Why do I have a well with low-quality water (or a small amount of water), while my neighbor has a good well?

The quality (and amount) of groundwater encountered in a well is strongly influenced by the rock types penetrated by a borehole (eg., Stone, 2001). For example, a well penetrating limestone may produce water that is “hard”, meaning the water contains 150 to 300 ppm calcium carbonate, while a well penetrating ash flow tuff will be relatively soft, with water containing <75 ppm calcium carbonate.

Abrupt changes in water quality (or amount) over short horizontal distances are usually related to the underlying geology. A geologic fault that might juxtapose a tuff against a limestone can cause a difference in water quality across property boundaries. Abrupt changes in rock type (e.g., a sandstone channel within a shale) can lead to sudden changes in water quality and quantity over a short horizontal distance.

Often, examination of a geologic map of your area can help you understand why your water well behaves differently than your neighbor’s water well.

How do I determine the quality of my water? Is my water safe to drink?

The New Mexico Environment Department conducts periodic "Water Fairs" around the state. Residents can get their well water tested for free at one of these events. To find out more about Water Fairs, contact the NMED Drinking Water Bureau toll-free at 1-877-654-8720.

The U.S. Geological Survey monitors both surface and ground water quality at 712 localities in the state of New Mexico.

Publications about water quality in particular areas in New Mexico can be obtained from the U.S. Geological Survey.

Click the Publications Warehouse button, and type the key words New Mexico water + your area of interest.

The U.S. Geological Survey has published about water quality data for the Albuquerque area (see Chapter 6) and Red River Valley.

The following New Mexico Bureau of Geology and Mineral Resources publications discuss water quality issues:

  1. Hydrologic Report 7: Selected papers on water quality and pollution in New Mexico, compiled by W. J. Stone, 1984, 300 pp.
  2. Open file Report 131: Water-quality data compiled for hydrogeologic study of Animas Valley, Hidalgo County, New Mexico, by K. M. O’Brien and W. J. Stone, 1982, 27 p., 5 maps
How can I protect our water resources?

The New Mexico Environment Department offers ideas for protecting New Mexico’s precious water resources from overuse and from pollution.

Other ideas are in: Stone, W.J., 2001, Our water resources: An overview for New Mexicans: New Mexico Bureau of Geology and Mineral Resources Information Series 1, 37 pp.

How do I determine my water rights?

Hydrologists at the Bureau of Geology are concerned with measuring and documenting the geologic characteristics of aquifers. The Office of the State Engineer manages water rights issues. Visit the webpage for the Office of the State Engineer for information about rules, regulations, and guidelines related to water use in New Mexico.

Water rights information can be found in the W.A.T.E.R.S. database. This database can be searched using either Township-Range-section, State Plane or UTM coordinate location information.

Information about water appropriation in the Albuquerque area is in Chapter 4 of a U.S. Geological Survey report entitled Ground Water Resources of the Middle Rio Grande Basin.

I’d like to drill a water well. What procedures are involved in drilling a well?

Hydrologists at the Bureau of Geology are engaged in practical research and field studies that delineate and characterize New Mexico’s streams and aquifers, and evaluate water quality problems. The Office of the State Engineer is charged with issuing well drilling permits and overseeing the diversion and beneficial use of the State’s waters. Visit the webpage for the Office of the State Engineer for information about well-drilling procedures, permits, and fees.