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Vol. 50-2 Federal Casenote

February 11, 2021

By Amanda Halter and Meredith Luneack

Federal Casenote

Not A Drop to Drink: Water Scarcity and Climate Change

Consequences at the US-Mexico Border


Climate change is a cognizable, widely recognized source of insecurity globally.[1] At the US-Mexico border, climate change is already negatively impacting the ability of inhabitants to access and control water at this crucial boundary area. As climate change intensifies, the Rio Grande and Colorado Rivers—the primary sources of water for much of the US-Mexico border—will likely face increasing aridity and heightened water insecurity and demand.[2] Climate scientists predict that, if greenhouse gas emissions continue unabated, there is a ninety-nine percent chance that a “mega-drought” will hit the Southwest region of the United States before the end of the twenty-first century.[3] One study concluded that, as drought occurs and becomes more severe and more likely, these conditions will negatively impact both northern Mexico water supplies and groundwater recharge.[4] Water scarcity will potentially displace millions of people; scientists predict that lack of water and extreme temperatures may force residents living in the border region may be forced to move within the next eighty years.[5]

The Issue and Compiling Factors

Six million residents and two million acres of farmland in the Rio Grande Valley on the eastern end of the US-Mexico border rely on the Rio Grande River as their primary water source; yet, the Rio Grande remains one of the most endangered rivers in the country.[6] Scientists predict that residents of the Rio Grande Valley will face a water supply shortage of 600,000 acre-feet (or, 1.955106e+11 liquid gallons) by 2060.[7] This reduction will likely result in conflict over the remaining water resources amongst farmers, ranchers, and residents of the quickly-urbanizing region. Already, this conflict has begun. According to one 2015 study, five of the irrigation districts serving about 340,000 acres of farmland in the Rio Grande Valley were at “the highest risk of needing push water”[8] during periods of drought.[9] This uptick in agricultural water needs runs up against human consumers of water in the Valley, thirty-five percent of whom live below the poverty line.[10] According to the same study, “there are likely to be significant public health and economic impacts” if cities in the Valley cannot secure water for their residents.[11]

The public health impact could likely be even more acute in border colonias. These unincorporated, low-income neighborhoods often sit far from established cities and towns and lack access to typical municipal services such as water and electricity hookups.[12] In colonias along the border in New Mexico, residents rely on hand-dug wells for drinking water, which cannot access water as deeply as professionally-installed wells.[13] Because of this, when the water table drops below the deepest point of colonia wells during the hottest months of the year, colonia residents do not have access to any groundwater whatsoever.[14] The State of New Mexico faces some of the most acute water stress in the world, comparable to that of the United Arab Emirates.[15]

Thus, how should water resources be distributed between residential and agricultural consumers? What is the correct crisis response if an aquifer dries up? Such questions are even more complicated for border states; due to their immediate proximity to Mexico and their reliance on shared water resources, solutions to water scarcity problems inherently must be binational and reflective of the intertwined nature of water dependence. Texas and Mexico alone share fifteen aquifers, for example.[16] The population concentration along the border only exacerbates the problem; there are fourteen discrete “binational urban systems” that feature dense, interconnected populations that are particularly vulnerable to water scarcity.[17] The potential for systemic water scarcity along the entire US-Mexico border is magnified when meaningful water management and climate change policies are not pursued and implemented.

Potential Solutions

The federal governments of both Mexico and the United States have recognized the need for a bilateral response to water management. Bilateral cooperation, political and scientific, as well as agreements, formal and informal, are the best available tools for navigating an increasingly complex resource management future, and there are noteworthy successes, too. For example, the Climate Assessment for the Southwest (CLIMAS), a National Oceanic and Atmospheric Administration (NOAA) program housed at the University of Arizona, often works with Mexican academic counterparts, such as the Colegio de Sonora and the Universidad de Sonora, on climate science research undertakings.[18]

Furthermore, the International Boundary and Water Commission (IBWC) is successfully pursuing binational cooperation in water management. With a Mexican section based in Ciudad Juarez, Chihuahua, and an American section based in El Paso, Texas, the IBWC is a binational body charged with monitoring and managing the implementation of water-related treaties between the United States and Mexico.[19] While the IBWC boasts a thick catalog of treaties and evidence of cooperation and agreement between the United States and Mexico—the IBWC in its original form was created soon after the original drawing of the border line in the Treaty of Guadalupe Hidalgo[20]—critics have characterized it as anachronistic and insufficiently responsive to the modern environmental challenges that face binational negotiators today.[21] An audit of much of the IBWC’s recent work reveals that it perhaps best functions as a mechanic rather than as a strategist; that is, it is calibrated to implement the specifications of a broader water policy, not to create the policy itself. As such, despite its staying power as a source of binational negotiation, the IBWC may not be the right place to turn for a source of policy when faced with imminent water scarcity (though it is certainly a major player in policy fulfillment); this is perhaps exemplified by the fact that the majority of the American IBWC Commissioners have had professional and academic backgrounds in engineering, hydrology, geology, and topography.[22]

If broader policy is not in the wheelhouse of the IBWC Commissioners, then perhaps it belongs in a more political sphere. The Agreement on Cooperation for the Protection and Improvement of the Environment in the Border Area (the “La Paz Agreement”), signed in 1983 by then-U.S. President Ronald Reagan and Mexico’s President Miguel de la Madrid, is the chief political-level agreement made between the two countries that still shapes and underscores modern approaches to water management and environmental protection more broadly at the border. The stated objective of the La Paz Agreement is to “establish the basis for cooperation between the Parties for the protection, improvement and conservation of the environment and the problems which affect it, as well as to agree on necessary measures to prevent and control pollution in the border area, and to provide the framework for development of a system of notification for emergency situations.”[23] Functionally the La Paz Agreement has served as a launching pad for a number of binational programs aimed at environmental protection and water conservation, including most recently the Border 2020 initiative, launched as a partnership between the American Environmental Protection Agency (EPA) and Mexico’s Secretaría del Medio Ambiente y Recursos Naturales (SEMARNAT).[24]

Introduced in 2012, Border 2020 set out to achieve a number of “sustainable development” goals, one of which was to improve access to clean drinking water for the inhabitants of the border region.[25] Border 2020 also made explicit mention of involving stakeholders from all levels as program partners, implementing a regional, “bottom-up” approach to goal setting and implementation.[26] Border 2020 works primarily through grant-funded initiatives financed by the North American Development Bank (NADB), and regional EPA offices oversee its implementation, providing resources and accountability for the community-level programs working on water protection and conservation.[27]

Despite its lofty goals, the Border 2020 initiative has been plagued with a number of problems, including insufficient reporting on outcomes, a lack of transparency, and failure to monitor important environmental indicators, according to the EPA Inspector General (IG) office. Chief among these challenges is the absence of meaningful documentation of progress. Regarding the composition of regional action plans meant to keep track of the grant-funded programs, for example, the IG reported that they were frequently inconsistent in format, lacked the requisite information, or failed to provide updated information.[28] The EPA also failed to share any metrics on success with the public, or any information on which programs received grants and whether or not they were successful.[29] Finally, despite the initiative’s stated goal of protecting the environment and public health in the border region, Border 2020 has failed to track how its work, or lack thereof, has affected the area’s environmental health; the most recent overview available on the environmental conditions at the border is a 2016 interim report.[30] Many of these failures can be attributed to a lack of funding; according to the IG, the EPA reported that it did not have the resources to track progress in the way that it should, and that “[w]ithout an additional means to track established Border 2020 Program environmental indicators, the program remains unable to determine whether it is accomplishing its stated goals and objectives.”[31]

A Holistic Approach

But because the above agreements are between countries as equal partners, cooperation and inclusion must be not only vertical, with regional and municipal stakeholders, but respected in good faith horizontally by both country partners. Such respect is difficult to consistently achieve, as political turnover occurs much more quickly in both countries than it often takes to achieve meaningful progress. Additionally, consistent violation of binational agreements can decrease goodwill between signatories; for example, some critics argue that the American pursuit of the construction of a border barrier across administrations violates the letter and spirit of the La Paz Agreement.[32] Is there a happy medium between the granular consistency of the IBWC and the political volatility of the La Paz Agreement and its ilk? With so many stakeholders with so many interests at so many levels, it is difficult to conceive of an agreement that could possibly take all perspectives into account. But perhaps as the danger of aridity and water shortages becomes increasingly stark and imminent, interests will coalesce, and differences between stakeholders will not matter as much as the existential need to secure water, in a sustainable way, for those living at the US-Mexico border.

Amanda Halter is managing partner of the Houston office of the international law firm of Pillsbury Winthrop Shaw Pittman, a member of the firm’s Environmental & Natural Resources practice section and co-leader of the firm’s Crisis Management team. Amanda helps companies resolve environmental liabilities and negotiate compliance conditions, as well as manage financial and reputational losses associated with a crisis. Her experience includes a diverse array of environmental regulatory, litigation and crisis matters, including contamination investigations and remedial actions, natural resource damages assessments and claims, environment, health and safety compliance counseling, mass toxic tort actions, permitting and planning for large-scale industrial projects, and project impacts mitigation and restoration strategies. Amanda is a native of Houston, a graduate of Rice University and The University of Texas School of Law.

Meredith Luneack is a third-year student at The University of Texas School of Law and a senior editor of the Texas Environmental Law Journal.


[1]               The National Security, Military, and Intelligence Panel on Climate Change of The Center for Climate and Security, A Security Threat Assessment of Global Climate Change 6 (Feb. 2020). 

[2]               Naveena Sadasivam, One of the Fastest Growing Regions of the US Could Run Out of Water, Quartz & The Tex. Observer (Aug. 21, 2018), 

[3]               Robinson Meyer, A Mega-Drought is Coming to America’s Southwest, The Atlantic (Oct. 11, 2016),

[4]               Margaret Wilder et al., In Assessment of Climate Change in the Southwest United States: A Report Prepared for the National Climate Assessment ch. 16 (G. Garfin et al. eds., Island Press 2013).

[5]               Meyer, supra note 3.

[6]               Zoe Schlanger et al., In a Warming World, The Fight for Water Can Push Nations Apart—Or Bring Them Together, Quartz & The Tex. Observer (Aug. 16, 2018),

[7]               Sadasivam, supra note 2.

[8]               Id. “Push water” is a source of surplus water to be tapped into during periods of drought. 

[9]               Id.

[10]             Jason Cohen, Rio Grande Valley Tops List of “America’s Poorest Cities”, Texas Monthly (Jan. 21, 2013),

[11]             Sadasivam, supra note 2.

[12]             Daniel Salinas, Drinking Water Along The US-Mexico Border Threatened by Global Warming, KBPS San Diego (Jun. 12, 2017), 

[13]             Id.

[14]             Id.

[15]             Morgan McFall-Johnsen, New Mexico faces extreme water scarcity on par with the United Arab Emirates. Experts warn more ‘day zeros’ are looming, Business Insider (Aug. 7, 2019), https://

[16]             Schlanger, supra note 6. 

[17]             Greg Garfin et al., Assessment of Climate Change in the Southwest United States, Southwest Climate Alliance 343 (2013). 

[18]             Id.

[19]             Nicole T. Carter et al., U.S.-Mexican Water Sharing: Background and Recent Developments, Congressional Research Service 5 (2017).

[20]             History of the International Boundary and Water Commission, Int’l Boundary & Water Comm’n,, (last visited Mar. 15, 2020).

[21]             Helen Ingram & David R. White, International Boundary and Water Commission: An Institutional Mismatch for Resolving Transboundary Water Problems, 33 Nat. Res. J., 153, 153 (1993). 


[22]             History of U.S. Section Commissioners, Int’l Boundary & Water Comm’n, /Commish_History.html (last visited Apr. 6, 2020).

[23]             Agreement on Cooperation for the Protection and Improvement of the Environment in the Border Area, U.S.-Mex., art. I, Aug. 14, 1983, 35 U.S.T. 2916. 

[24]             U.S. Envtl. Prot. Agency & Mex. Sec. of Env. & Nat. Res., EPA-160-R-12-001, Border 2020: U.S.-Mex. Envtl. Program (2012).

[25]             Id. at 1.

[26]             Id. at 8.

[27]             U.S. Envtl. Prot. Agency Off. of the Inspector Gen., 20-P-0083, Border 2020: Mgmt. Controls Needed to Verify and Rep. Border 2020 Program Accomplishments 3 (Feb. 18, 2020).

[28]             Id. at 8–9.

[29]             Id. at 10–11.

[30]             Id. at 9.

[31]             Id. at 10.

[32]             Oscar Ibanez & Stephen P. Mumme, U.S.-Mexico Environmental Treaty Impediments to Tactical Security Infrastructure Along the International Boundary, Nat. Res. J., 817-18 (2009).