United States – Mexico Transboundary Aquifer Assessment

1. Proposal United States – Mexico Transboundary Aquifer Assessment By Dr. Karl Wood, Director Water Resources Research Institute New Mexico State University Las Cruces, New Mexico

2. 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

3. border Water Resources in the New Mexico Border Region

5. 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 Hueco Bolson

6. Mesilla Basin • Largest rechargeable reservoir in region • Southern boundary in Mexico poorly defined • Connected with overlying semi-confined 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 bi-national

7. Jornada del Muerto • Weak connection with Mesilla Basin • Quality <1,000 mg/L TDS in south • Limited development • Very little natural recharge ~5,000 af/y in southern area • Some modeling in southern area • Water in storage = ~100 million af • Well yields low

8. Mimbres Basin • Interconnected group of subbasins • Area = 5,140 mi2, 4,360 in US, 770 in MX • Water is storage = ~30 million af • Quality <250 mg/L TDS in north, >500 to 1,000 mg/L TDS in south • Southern boundary poorly defined • Water use: ~53,000 af/y in US • Recharge ~63,000 af/y • Limited modeling in Deming area, none bi-national

9. Hachita-Moscos Basin • Interconnected Group of subbasins • Area 1,040 mi2, 620 in NM, 420 in MX • Water in storage ~5 million af • Recharge = 4,800 af/y • Flow from US to MX about 2,000 af/y • Quality variable with areas having <250 mg/L TDS to >1,000 mg/L TDS • Limited development • No modeling, sparse data

10. Playas Basin • Two Interconnected subbasins • Area 925 mi2, 921 in NM, 4 in MX • Water in storage ~5 million af • Recharge = ~5,700 af/y • Quality variable with areas having <250 mg/L TDS to 500 mg/L TDS • Water use ~4,900 af/y for mineral processing (1995) • No modeling, sparse data

11. Animas Basin • Interconnected group of four subbasins • Area 2,448 mi2 • Water in storage ~9.5 million af • Recharge = ~12,700 af/y • Quality <250 mg/L TDS • Water use ~16,500 af/y in 1995 primarily for agriculture • No modeling, limited data

12. Many questions concerning the aquifers remain: • How extensive are the aquifers? • Which directions are the aquifers flowing? • How deep are the aquifers? • 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?

13. Solution: A Congressionally funded initiative to a. Develop high-quality, comprehensive, binational groundwater quantity and quality databases b. Assess movement and interaction of water resources c. Analyze trends in groundwater quality, including salinity, nutrients, toxics, and pathogens d. Develop and improve groundwater flow models for bi-national aquifers to facilitate regional water assessment and planning • Develop land use and land cover characterization mapping • information f. Develop hydrogeologic maps of both surface and bedrock deposits g. Apply the new data and models to evaluate strategies to enhance supplies and protect water quality

14. Where will the work be done? Primary emphasis will start in the southern New Mexico – west Texas - northern Chihuahua region Secondary emphasis will follow in the Arizona – Sonora and California – Baja regions

15. Who will do the work? Lead agencies: New Mexico Water Resources Research Institute at New Mexico State University Texas Water Resources Research Institute at Texas A&M University Scientists from: New Mexico State University New Mexico Tech University Texas A&M University – El Paso Research Center U.S. Geological Survey – New Mexico & Texas Offices University of Arizona University of California – Riverside Sandia National Laboratory Mexican counterparts

16. Funding? U.S. Senate Bill 1957 108th Congress Introduced November 25, 2003 By U.S. Senator Jeff Bingaman $5 million each year for 10 years

17. Action Request? Resolution of support be sent to New Mexico’s Congressional Delegation Senator Jeff Bingaman Senator Pete Domenici Representative Steve Pearce Representative Tom Udall Representative Heather Wilson

18. New Mexico Delegation Texas Delegation Senator Jeff Bingaman 703 Hart Senate Office Building Washington, D.C. 20510 Senator Pete Domenici 328 Hart Senate Office Building Washington, D.C. 20510 Congressman Steve Pearce 1408 Longworth House Office Building Washington, D.C. 20515 Congresswoman Heather Wilson 318 Cannon House Office Building Washington, D.C. 20515 Congressman Tom Udall 1414 Longworth House Office Building Washington, D.C. 20515 Senator John Cornyn 517 Hart Senate Office Building Washington, D.C. 20510 Senator Kay Bailey Hutchison 284 Russell Senate Office Building Washington, D.C. 20510 Congressman Silvestre Reyes 1527 Longworth House Office Building Washington, D.C. 20515 Congressman Henry Bonilla 2458 Rayburn House Office Building Washington, D.C. 20515