The Transboundary Aquifer
Assessment Act:
Program Objectives and Status
Dr. Karl Wood New Mexico Water Resources Research Institute
Dr. Sharon Megdal Arizona Water Research Center
Dr. Ari Michelsen Texas A&M Research Center at El Paso
James Stefanov U.S. Geological Survey – Austin, Texas
Problems?
• Human population growth along US-Mexico border is among
the highest nationally
• Average per capita income is far below the U.S. average
• Economic develop is restricted by lack of adequate water
• Availability of water is a key issue in the U.S. – Mexico border
region
• Groundwater is used for all the drinking water in
southern New Mexico, all of Juarez, and half of the El
Paso area
• Groundwater is probably the only source of new
water as the drought continues and new desalting
technology develops
Many questions concerning the aquifers
remain:
• How extensive are the aquifers?
• How deep are the aquifers?
• How thick are the aquifers?
• Which directions are the aquifers flowing?
• What is the quality of the aquifers at various depths?
• How fast are they declining in supply and quality?
• What is the long-term availability?
• What is the relationship between surface supplies
and aquifer recharge?
Water Resources in the New Mexico Border Region
b
o
r
Hueco Bolson
 Mined basin with water-level drawdowns
exceeding 250 feet
 Sole source of water for Ciudad Juarez
 Major source of water for El Paso
 Quality generally <1,000 mg/L TDS, but
deteriorating
 Very little natural recharge
 Extensive modeling in El Paso/Ciudad
Juarez area
 Artificial recharge program by El Paso
 Water Use 2000:
El Paso = 126,420 acre-feet
Ciudad Juarez = 124,000 acre-feet
Distrito de Riego 009 = 57,000
acre-feet
Mesilla Basin
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Largest rechargeable reservoir in
region
Southern boundary in Mexico poorly
defined
Connected with overlying semiconfined alluvium aquifer
Quality <1,000 mg/L TDS
Use: Domestic & Supplemental to Rio
Grande for Irrigation
Quantity pumped = ?
Quantity in storage = ~60 million af - ?
Number of modeling efforts, none binational
The Act
• Conceived by Senator Jeff Bingaman of New Mexico
from U.S. Senate field hearing in Las Cruces August
14, 2001
• Authorization bill written by Senator Bingaman’s
staff
• Sponsored by Senator Bingaman of New Mexico and
Co-Sponsored by Senator Domenici of New Mexico
and Senator Kyl of Arizona
• Supported by other Senators from Arizona and Texas
• Passed U.S. Senate in 2005
The Act continued
• Sponsored in U.S. House by Congressman Kolbe
of Arizona and co-sponsored by Congressmen Grijalva of
Arizona and Reyes of Texas in 2006
• Supported by Congressmen from Arizona, New Mexico, and
Texas
• Not supported by Congressmen from California
• Passed Congress in December 2006
• Signed by President in December 2006
The Act - Objectives
• Collect new and existing data
• Improve existing and develop new computer models to:
– Characterize transboundary aquifers for:
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Horizontal extents
Depth to aquifers
Thickness of aquifers
Anomalies of aquifers
Water qualities of aquifers including salinity, nutrients, toxics, and pathogens
Movement of water in aquifers
Assess interaction with surface waters
Sources and amounts of depletion of aquifers
– Develop high-quality, comprehensive, binational groundwater quantity and quality
data bases
– Develop hydrogeologic maps of both surficial and bedrock deposits
– Apply the new data and models to evaluate strategies to protect water quality and
enhance supplies.
The Act – Some Bumps
• International Boundary and Water Commission’s (IBWC)
Commissioner supported the Act to gain information to write a
groundwater treaty with Mexico
• State Engineers in Arizona, New Mexico, and Texas opposed
the bill because groundwater in U.S. belongs to the states and
not to the federal government
• IBWC backed off of treaty ambitions
• State Engineers eventually supported the bill
• California’s congressmen felt the information could
complicate issues surrounding the All-American Canal
The Act continued
• Bill was authorized for $5 million per year for 10
years
• Appropriation now needed
• Budget for 2007 is a continuing resolution
• Budget request for 2008 is $2 million for startup
Who Gets The Money?
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50% to the Arizona, New Mexico, and Texas Water
Resources Research Institutes to provide funding to
appropriate entities including:
1.
2.
3.
4.
5.
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Universities
State agencies
The Tri-Regional Planning Group
Sandia National Laboratory
Other relevant organizations and entities in Mexico
50% to the U.S. Geological Survey to work in partnership
with the above organizations
Priority Aquifers
• Hueco Bolson – Texas, New Mexico, & Chihuahua
• Mesilla Bolson - Texas, New Mexico, & Chihuahua
• Santa Cruz River Valley – Arizona & Sonora
• San Pedro Aquifer – Arizona & Sonora
• Additional aquifers to be added i.e Mimbres, etc.
Programs Already Started
• Development of a bibliography in English and
Spanish
• Determining existing data sources, extent, & form
• Developing a relationship Mexico’s new Office of
Transboundary Basins established in the National
Water Commission
• Updating colleagues in:
– International Boundary & Water Commission
• U.S. Division
• Mexico Division (CILA)
– University of Ciudad Juarez
– Juarez campus of Monterrey Tech
– El Colegio de la Frontera Norte (COLEF)
Question?