Aquifers or Bolsons are
underground areas that store significant amounts of water. After
rain or melted snow the water will evaporate, get used by plants,
runoff onto surface areas such as rivers, streams, or lakes. It
can percolate through the porous soil and fill spaces between soil
and rocks. Not all aquifers are the same; there are different soils,
rocks and mineral types that make each aquifer unique. The aquifers
in the El Paso area consist of very fine-grained sands and gravels.
Water stored underground may be anywhere from days old to thousands
of years old, it depends on the depth of the aquifer.
Hueco Bolson is the
principal aquifer for the El Paso-Juarez area. It occupies the majority
of El Paso County. It extends from the Franklin Mountains on the
west, to the Hueco Mountains on the east. The Hueco Bolson extends
northward in to New Mexico and southward into Mexico. In 2002, El
Paso pumped about 30 percent of its water from the Hueco Bolson.
In 2001 pumping was 44 percent, while in 2000 it was 47 percent.
In an effort to meet future demands, the Hueco Bolson will continue
to be used as a major source of water that is either fresh or slightly
brackish, since it contains a layer of brackish water (water which
has a greater amount of salt). After many years of groundwater pumping,
the quality of the groundwater in selected areas of the Hueco Bolson
has become more brackish. As a result the concerns about water available
and levels of salinity in the El Paso are has increased. Groundwater
flow models are being used as a tool to predict how the aquifers
might respond to pumping, and better understand the complex interaction
between the fresh and brackish water. The brackish water will be
desalinated as part of the Fort Bliss/El Paso Water Utilities Joint
Desalination Project. The project is underway as the plant is designed
as the plant is designed with a capacity of 27.5 million gallons
of water per day. It will include a learning center to assist the
community in understanding the treatment process of drinking water
and increase awareness of the challenges this region faces in the
Chihuahuan Desert. The plant is expected to be operational in the
Ciudad Juarez, which has roughly double the population of El Paso,
depends 100 percent on water from the Hueco Bolson to meet its demands.
The groundwater in Juarez is brackish and other future sources of
quality water are being currently investigated.
Bolson is located primarily in New Mexico with small portions in
Mexico and Texas. The northern boundary of the Mesilla Bolson is
the Robledo and Doña Ana mountains. Much of the southern
boundary is in Mexico, while the western boundary is formed by the
West Potrillo and the East Potrillo mountains. The eastern boundary
is the Franklin Mountains.
The main hydrologic feature
of the Mesilla Bolson is the Rio Grande. The river enters the basin
through Selden Canyon and runs through the Mesilla Valley and exits
as it narrows in El Paso. The Rio Grande and the irrigation
system fed by the Rio Grande are considered the main source of recharge
to the Mesilla Bolson. Water levels in the aquifer remain relatively
constant with fluctuations being primarily in response to flows
in the Rio Grande and irrigation canals and drains.
The top of the underground area where every available space is filled
with water (saturation).
An aquifer that is surrounded by impermeable layers that transmit
water slower than the aquifer. This aquifer is under pressure and
can also be called an artesian aquifer.
An aquifer without protective material above. It is vulnerable to
contamination from surface activities.
Portion of aquifer that contains porous rock materials that allow
water to penetrate freely.
Portion of aquifer that contains rock material, or clay layer, that
does not allow water to penetrate or pass through easily.
The direction in which groundwater flows; similar to down hill for
surface water flows
The natural force of attraction exerted by Earth on objects or materials
on its surface that tends to draw them down toward its center
Deep wells that place water back into the aquifer.
To force a substance into another, such as seawater into a natural
fresh water source.
Downward movement of water through the soil layers.