Water Resources Management at the Mexican Boundary with the USA

1. Water Resources Management at the Mexican Boundary with the USA Javier Aparicio Mexican Institute of Water Technology Ministry of Environment and Natural Resources México

2. Instituto Mexicano de Tecnología del Agua Deals primarily with water related issues in order to help reaching the sustainable development for the country, by conducting research and technological development (R&D) in collaboration with public and private institutions, universities and other research centers such as NGO’s.

3. Four main research divisions • Hydrology • Water Quality • Irrigation and drainage • Hydraulics • Professional development

4. In the near future, it is expected that conflicts between neighbour municipalities, counties and even countries will be related to water. To avoid that, it is necessary to create transboundary water use policies in which all the parts involved agree to make the efficient use and proper long and short term planning.

5. México/USA Boundary • 3000 km • 14 cities • 10.6 million in 2000 • 55% US, 45% México • 14 million in 2020

6. TIJUANA RIVER WATERSHED TOTAL = 4,424 km2 US A = 1,221 km2 MEXICO = 3,203 km2 WYOMING COLORADO RIVER WATERSHED TOTAL = 634,840 km2 U T A H U S A = 631,000 km2 NEVADA COLORADO MEXICO = 3,840 km2 CALIFORNIA BRAVO/GRANDE RIVER WATERSHED NUEVO ARIZONA MEXICO TOTAL = 444,560 km2 U S A = 229,798 km2 MEXICO = 214,762 km2 SONORA TEXAS CHIHUAHUA PACIFIC COAHUILA OCEAN GULF N OF NUEVO DURANGO MEXICO LEON Watersheds México/USA 1944 Treaty

7. Gulf of California or Gulf of Cortés Colorado River • 634,840 km2 • 7 USA States: Colorado River compact • 2 Mexican States

8. One of the most exploited rivers in the world: 20,700  5,200hm3 in 100 years • 1,850.2 hm3/yr to México; 2097 when there are excedents Colorado River flows Hoover Dam • Nearly 100% of water is used for agriculture & urban supply Glen Canyon Dam • Droughts are shared 1000 acre-ft=1.233 hm3

9. Droughts, Colorado River • In case of extraordinary drought or a serious accident in the irrigation system in the USA which would prevent delivering the guaranteed volume, the assigned volumes to Mexico would be reduced in the same proportion as the consumption reduction in the USA.

10. Colorado River: Salinity • Salinity not in the Treaty • 1961: Increase in salinity above 2,500 ppm • IBWC Negotiations: Act 242 (1973) • Bypass channel • Salinity < Imperial Dam +121 ppm; higher at San Luis Imperial dam Imperial Valley Morelos dam San Luis Río Colorado Mexicali Valley

11. Colorado River: Salinity San Luis Morelos Imperial Source: CILA

12. 70´s and 80´s Last 2 decades Before 1930 Delta Region • One of the biggest desert estuaries in the world • 780 000 ha • Highly diversified collection of plants, birds and marine species • Dry and dead system of small wetlands and salt marshes • Highly salinized desert • Floods, surplus, return flows • 60 000 ha restoration • Significant wetland ecosystem in SW USA and NW México in danger

13. SALTON SEA IMPERIAL VALLEY MEXICALI VALLEY LAGUNA SALADA SANTA CLARA SLOUGH ALTAR DESERT SEA OF CORTÉS Delta Region Near future • Significant population increase • Pressure over land, water and other resources • Permanent flows vs. Interim Surplus Criteria • Legal issues

14. Actions • Establishment of the Alto Golfo de California y Delta del Río Colorado Biosphere Reserve • Wastewater treatment plants in Border Cities and recycling • Efficient water use programs • Legal framework modifications: New National Water Law • Ecological priority • Incentives to water consumption reduction • Program Border XXI • Public participation • Capacity building • Interinstitutional cooperation • Binational workgroups for R&D

15. Bravo/Grande River • Boundary: 2,001 km • Total runoff : 11,000 hm3/year • Total storage capacity: 23,000 hm3 • 1944 Treaty: Fort Quitman to mouth

16. R i o B r a DR CD JUÁREZ 009 v o • Fort Quitman DR BAJO RÍO CONCHOS 090 P LA AMISTAD Arroyo Las Vacas Río Conchos DR PALESTINA 006 P CENTENARIO Río San Diego P LUIS L. LEÓN P SAN MIGUEL P LA FRAGUA P EL REJÓN Río Chuviscar Río San Rodrigo Río Escondido DR DELICIAS 005 DR DON MARTÍN 004 P CHIHUAHUA P FRANCISCO I. MADERO Río San Pedro P VENUSTIANO CARRANZA P LA BOQUILLA DR ACUÑA FALCÓN 050 Río Conchos DR RÍO FLORIDO 103 Río Florido P FALCÓN Río Salado DR BAJO RÍO SAN JUAN 026 P SAN GABRIEL LAS LAJAS 031 RíoSan Juan P MARTE R. GÓMEZ DR BAJO RÍO BRAVO 025 P EL CUCHILLO Agricultural use, Bravo Basin

17. Bravo/Grande River USA 1/2 Gulf of México 1/2 Falcón Dam La Amistad Dam Bravo/Grande Fort Quitman 1/2 1/2 • 74 hm3/yr at Juárez (1906) • 431.7 hm3/yr in 5-yr cycles • 1953-2002: 26 periods • Cycle 25 completed in 2001 • Deficit in cycle 26 • Droughts are not shared Salado Conchos Gauged rivers 1/3 US 2/3 México

18. Droughts, Bravo/Grande River • In case of extraordinary drought or a serious accident in the Mexican hydraulic system which would prevent Mexico to deliver such volume, any undelivered volume at the end of the 5-year period would be distributed in the following period with water from the same tributaries.

19. Actions • Wastewater treatment plants in Border Cities • Efficient water use programs • Binational workgroups for R&D • Río Bravo water distribution rule • Irrigation modernization and technology improvement in Conchos River Basin

20. Río Bravo water distribution rule • Define Extraordinary drought • Distribute US assignment among Mexican tributaries • Propose to subject deliveries to US with the same deficit restrictions as Mexican irrigation assignments • Consensus building on distribution rule among users

21. Modernization and technology improvement, Conchos Basin • Channels and network lining • Control structures and wells rehabilitation • Low pressure, drip and sprinkler systems • Land leveling • Real-time irrigation forecast • Efficiency: 33  55% • Recover 396 hm3/yr in 4 years • 2002-2006, US $150 million • NADBank Fund and Federal investment

22. Water quality, Tijuana • 32 hm3 of treated residual water with organic contaminants to the Pacific Ocean • Industrial residuals discharges 8 hm3/year. • Volumes generated are higher than plant capacity: serious pollution problems

23. N 1 Baja California 2 5 6 3 4 Mapa de la región Nte 7 Sonora Chihuahua Coahuila N. León 1.Mexicali Valley 2. Sonoita River Tamaulipas 3. Santa Cruz River 4. San Pedro River 5. Conejos-Médano aquifer 6.Juárez Valley 7. La Amistad observation wells Transboundary aquifers • Mexicali: Recharge/ exploitation: 150/ 102 hm3; All-American channel lining? • Juárez Valley: Drawdowns > 45 m; quality problems

24. Conclusions • México and USA share a politically, sociologically and hydrologically complex and rapidly evolving boundary • International agreements have been the result of long negotiations made in good will and with the benefits of both countries in mind:examples by other Countries

25. Conclusions • Population growth and comprehensive water use: careful joint water resources management in the boundaries • Sustainable development binational plans, including Colorado Delta ecology • Integrated international hydrometeorological information system along the Border • Efficient water use programs • Binational R&D programs