From Science to Law: Transboundary Ground Water Resources and Emerging International Law

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1 From Science to Law: Transboundary Ground Water Resources and Emerging International Law Gabriel Eckstein, Professor of Law Vermont Law School 14 June

2 Outline What is ground water? Ground water in an international context Case study: transboundary aquifers on the Mexico-US border International law for transboundary aquifers Concluding observations 2

3 Ground Water 101 What is ground water? water occupying voids, cracks or other spaces between particles of clay, silt, sand, gravel or rock within the saturated zone of a geologic formation /watch?v=onwaerr_xee 3

4 What is an aquifer? Ground Water 101 a permeable geologic formation (such as sand or gravel) that has sufficient water storage and transmitting capacity to provide a useful water supply via wells and springs earthguide/diagrams/groun dwater/ 4

5 Ground Water 101 5

6 Ground Water 101 Unconfined Aquifer aquifer bounded by an impermeable base layer of rock or sediments and overlain by layers of permeable materials extending from the land surface to the impermeable base of the aquifer Confined Aquifer aquifer contained between two impermeable layers the base or floor, and the ceiling strata that subject the stored water to pressure exceeding atmospheric pressure 6

7 Ground Water 101 Recharging Aquifer Aquifer that is connected to the hydrologic cycle and has a continuous source of recharge Non-Recharging Aquifer Aquifer that is completely detached from the hydrologic cycle and obtains insignificant or no recharge Recharge Zone porous surface and subsurface area through which an aquifer s ground water may be recharged Discharge Zone area through which an aquifer discharges ground water onto the surface or into another water body 7

8 Ground water: The international context 8

9 Ground water: The international context Globally ground water supply comprises: 30% of all fresh water resources 98% of liquid fresh water resources The most extracted natural resource in the world (982 k 3 in 2015) Global ground water use: Provides ~1/2 of humanity with freshwater for everyday uses such as drinking, cooking and hygiene 60% to 99% of drinking water for Europeans 50% to 97% of drinking water for Americans 40% of water used by industry 20% of water used in irrigated agriculture From: Comprehensive Assessment of Water Management in Agriculture Water for Food, Water for Life: A Comprehensive Assessment of Water Management in Agriculture, available at: 9

10 Ground water: The international context 10

11 Ground water: The international context 11

12 273 transboundary watercourses 3,600 watercourse treaties since ~800AD / 400+ since 1820AD 2 global watercourses agreements 12

13 600+ transboundary aquifers and aquifer bodies Source: International Groundwater Resources Assessment Centre (IGRAC): 13

14 Case Study: Mexico-US TBAs 14

15 Mexico-US TBAs Case Study 15

16 Mexico-US TBAs Case Study Sole source of potable water for 90%+ of communities along Mex-US border Columbus-Palomas (New Mexico- Chihuahua) Bisbee-Naco (Arizona-Sonora) Ambos Nogales (Arizona-Sonora) Sonoyta-Lukeville (Arizona-Sonora) Ambos Tecate (California-Baja California) Ciudad Juarez (Chihuahua) Others 16

17 Mexico-US TBAs Case Study Where are the TBAs? How many TBAs are there on the Mex-US border? 17

18 Mexico-US TBAs Case Study 20 = GNEB (Good Neighbor Environmental Board), Water resources management on the US Mexico border. Washington, DC: EPA. Eighth report to the President and the Congress of the United States (2005) 18 = S. Mumme, Minute 242 and beyond: challenges and opportunities for managing transboundary groundwater on the Mexico US border, 40 Nat Resour J. 341 (2000) 10 = International Groundwater Resources Assessment Centre (IGRAC) (2009) 8 = UNESCO, Final Report: 2nd Coordination Workshop. UNESCO/OAS ISARM Americas Programme Transboundary Aquifers of the Americas, El Paso, TX, November 2004 (2005) 18

19 Mexico-US TBAs Case Study 19

20 Mexico-US TBAs Case Study Study = Identifying and Characterizing Transboundary Aquifers Along the Mexico-US Border: An initial assessment Purpose = Identify and characterize TBA on Mex-US border in order to ascertain appropriate aquifer units for governance/management General Methodology Collect data and information generated on both sides from federal, state and local agencies, universities, nongovernmental organizations, research institutes, and private sources where available Identify and characterize TBA on the border Generate recommendations for appropriate aquifer units for governance/management 20

21 Mexico-US TBAs Case Study Types of data/info collected Aquifer characteristics (e.g., hydrogeology, chemistry, flow, etc.) Environmental surroundings (e.g., precipitation and climate, etc.) Geography (e.g., geographic extent, location, etc.) Recharge/discharge (e.g., natural and artificial, rates, locations, etc.) Human uses and dependencies Environmental/ecosystem reliance Challenges Locating information especially on US side Disparate methodologies between and within the two countries Inconsistent information between and within the two countries 21

22 STATES (MEXICO-US) BAJA CALIFORNIA-CALIFORNIA BAJA CALIFORNIA-CALIFORNIA- SONORA-ARIZONA SONORA-ARIZONA Level of information available/research to define the transboundary character (1) Tijuana/San Diego- (Tia Juana, Otay Mexico-US Case Study Sweetwater and Mission system) (2) Tecate/Potrero Valley and Campo Valley (3) La Rumorosa-Tecate/Jacumba Valley and Davies Valley (4) Laguna Salada/Coyote Wells Valley Cuenca Baja del Rio Colorado system (5) Valle de Mexicali/ Imperial, Ogilby and Yuma Valley Cuenca Baja del Rio Colorado system (6)Valle San Luis Rio Colorado/Yuma Sonoyta-Papagos system (7) Los Vidrios/Western Mexican Drainage (10) Rio Altar/Tucson AMA (8) Sonoyta-Papagos/San Simon Wash (12) Nogales/Santa Cruz (TAAP1) (9) Arroyo Seco/Tuscon AMA (11) Rio Alisos/Santa Cruz (13) Santa Cruz/Santa Cruz-San Rafael (TAAP1) SONORA-ARIZONA-NEW MEXICO (14) San Pedro/San Pedro (TAAP2) (15) Rio Agua Prieta/Douglas (INA) (16) Arroyo San Bernardino/San Bernardino Valley-San Bernardino basin CHIHUAHUA-NEW MEXICO (19) Los Moscos/Moscos Hachita (17) Janos/Animas and Playas aquifer basin (18) Ascencion/Los Moscos-Hachita CHIHUAHUA-TEXAS-NEW MEXICO (20) Josefa Ortiz de Dominguez/Mimbres (21) Las Palmas/Mimbres (22) Conejos Medanos/Mesilla Bolson (TAAP3) (23) Valle de Juarez/Hueco Bolson (TAAP4) CHIHUAHUA-TEXAS (24) Valle del Peso/West Texas Bolsons (25) Bajo Rio Conchos/West Texas Bolsons (26) Alamo Chapo/Igneous (27) Manuel Benavides/Lower aquifers COAHUILA-TEXAS (31) Presa La Amistad/Edwards (29) Serrania del Burro/Edwards (28) Santa Fe del Pino/Lower aquifers (33) Allende-Piedras Negras/Lower aquifers (30) Cerro Colorado-La Partida/Edwards (32) Palestina/Lower aquifers NUEVO LEON-TEXAS (34) Hidalgo/Carrizo Wilcox (35) Lampazos/Anahuac-Carrizo Wilcox TAMAULIPAS-TEXAS (36) Bajo Rio Bravo/Carrizo Wilcox-Gulf Coast (Yegua Jackson no data) Total

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24 Mexico-US TBAs Case Study Minute 242 of 1973 (amendment to 1944 Colorado, Tijuana, Rio Grande treaty) 5 = pending development of a comprehensive groundwater agreement, countries agree to limit withdrawals from aquifer along the Arizona-Sonora border near San Luis 6 = requires prior consultation prior to pursuing new surface or groundwater projects, or other action that could adversely impact the other side 24

25 International Law for Transboundary Aquifers 25

26 International Law for TBAs Recognition of transboundary groundwater resources as primary issue Minute 242 between Mexico/U.S. (1973) Convention on the protection, utilisation, recharge, and monitoring of the Franko-Swiss Genevois Aquifer (1978/2008) Nubian Sandstone Aquifer System monitoring and information exchange agreement (2000) Northwestern Sahara Aquifer System consultation mechanism agreement (2002) EU Groundwater Directive (2006) UNILC s Draft Articles (begun in 2002; submitted to UNGA in 2008) Iullemeden Aquifer System MoU (2009/2014) Guarani Aquifer Agreement (2010) Disi Aquifer MoA (2015) 26

27 International Law for TBAs Procedural Rules Regular exchange of data/information Monitoring Prior notification of planned measures Substantive Rules Cooperation Basis Very little state practice Handful of instruments, some have not been tested or implemented, and some with few enforceable obligations Aspiration of various academics 27

28 International Law for TBAs: Moving Forward Issues to address Obligation to manage transboundary implications (e.g., harm, pollution, etc.) Basis for allocating water, uses, and/or benefits Protection of the functioning of a transboundary aquifer Protection of recharge and discharge zones Protection of transboundary aquifer-dependent ecosystems Harmonization of metadata and methodologies Exploitation of non-recharging transboundary aquifers Joint institutional mechanisms Cross-border public participation Degree of sovereignty over transboundary aquifers 28

29 More information Identifying and Characterizing Transboundary Aquifers Along the Mexico-US Border: An initial assessment, Journal of Hydrology, Vol. 535, pp (2016) (co-authored with Dr. Rosario Sanchez and Victoria Lopez, Water Management and Hydrological Sciences Program, Texas A&M University) ( Rethinking Transboundary Ground Water Resources Management: A Local Approach along the Mexico-U.S. Border, Georgetown International Environmental Law Review, Vol. 25(1), pp (2013) ( Managing Buried Treasure Across Frontiers: The International Law of Transboundary Aquifers, Water International, Vol. 36(5), pp (2011) ( State Practice in the Management and Allocation of Transboundary Ground Water Resources in North America, Yearbook of International Environmental Law 2007, Vol. 13(3), pp (2008) (co-authored with Amy Hardberger, St. Mary s Law School) ( 29

30 Gabriel Eckstein Professor of Law Texas A&M University