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The International Lawyer

The International Lawyer, Volume 57, Number 2, 2024

Avoiding Water Wars: Water Allocation, Use, Ownership, and Sharing on the Rio Grande

Jennifer Weaver


  • During summer 2020, there was a protest in reaction to a conflict over a water-sharing agreement between the United States and Mexico.  
  • When the problem remained unresolved three months later, in September 2020, protestors, including farmers and ranchers, seized control of the La Boquilla dam until Mexican National Guard troops were able to wrest it away, killing one woman in the process.
  • The issue of just allocation of water—a limited and precious resource in the desert region that includes both the United States and Mexico—remains, and future conflict is likely to arise if long-term solutions are not realized.
Avoiding Water Wars: Water Allocation, Use, Ownership, and Sharing on the Rio Grande
Jeff R. Clow via Getty Images

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I. Introduction: A Harsh Setting

In the midst of the tumultuous summer of 2020, a familiar scene was being played in the Mexican border city of Ojinaga, Chihuahua, which sits at the convergence of the Conchos River in Mexico and the Rio Grande. A large and agitated crowd gathered outside a government building where several fearful officials had barricaded themselves inside. Protesters in the street overturned three vehicles and torched another. Another group of protesters blockaded the international bridge that connects Ojinaga to its sister city Presidio, Texas, shutting off all vehicle traffic for three days. But this protest had a very different cause than others taking place at the same time; the Ojinaga protest was a reaction to a conflict over a water-sharing agreement between the United States and Mexico. When the problem remained unresolved three months later, in September 2020, protestors, including farmers and ranchers, seized control of the La Boquilla dam until Mexican National Guard troops were able to wrest it away, killing one woman in the process. Local Mexican farmers were angry that water from the Rio Conchos, desperately needed for crops in the midst of a severe drought, was soon to be delivered to the United States under the terms of a 1944 water treaty. The conflict was temporarily settled in October 2020, but the issue of just allocation of water—a limited and precious resource in the desert region that includes both the United States and Mexico—remains, and future conflict is likely to arise if long-term solutions are not realized.

The importance of the water that flows into the Rio Grande from the Rio Conchos cannot be overestimated. The Rio Grande today forms the international boundary between the United States and Mexico, but for centuries before either country existed, the region was known as “La Junta de los Ríos,” the Joining of the Rivers. While these two rivers together sustained extensive permanent human settlements from pre-historic times, several more recent developments have caused the Rio Conchos to become the more vital of the two in the northern Chihuahuan Desert. First, completion of the Elephant Butte Dam in 1916 in southern New Mexico greatly reduced the flow of the Rio Grande into Texas and Mexico. South of the dam, the growing city of El Paso today takes 40 percent of its potable water from the Rio Grande. Agricultural use south of El Paso depletes it still further, and as a result, the segment between Sierra Blanca, Texas, and the influx of the Rio Conchos is often completely dry.

Because the demand for water is rapidly increasing on both sides of the border, compromises that have been effective in the past may be less effective today, and supplying water to various interested parties on both sides of the border will require continued cooperation and creative solutions if water wars are to be avoided in the future. The aforementioned water treaty, signed in 1944, was the first and the most important in a series of water agreements between the United States and Mexico. But, the evolving concerns of both countries, including water quality, environmental preservation, an emerging natural gas “fracking” industry, and increased residential water use, have caused some experts to question the continued viability of the 1944 Treaty. Nonetheless, because the treaty contains an ingenious built-in system of continual amendments, it not only remains relevant in light of changing circumstances, but it is also useful as a model treaty for other countries who share water sources on their international boundaries and wish to avoid conflict over water quality, use, and allocation.

II. The Existing Legal Framework: How and Why It Works

The Ojinaga water protests in 2020 were remarkable because they were anomalous; despite the momentary conflict, water sharing between the United States and Mexico has been generally peaceful due to the well-written provisions of two water treaties. The first of these was the Utilization of Waters of the Colorado and Tijuana Rivers and of the Rio Grande Treaty Between the United States and Mexico, which was signed in 1944 (the “1944 Treaty”). This treaty, though completely lacking in any enforcement mechanism, laid the groundwork for successful water sharing through its unique built-in amendment process, often called the “minute system.” The treaty provided for the creation of two independent government agencies, one in Mexico under the direction of the Mexican Ministry of Foreign Affairs and one in the United States which is guided by the foreign policy of the Department of State. With respect to the United States agency, the 1944 Treaty expanded the scope of the International Boundary Commission (est. 1889) and changed its name to the International Boundary and Water Commission (IBWC). The Mexican counterpart to the IBWC is the Comisión Internacional de Límites y Aguas Entre México y los Estados Unidos (CILA). Each is headed by a single commissioner. The IBWC/CILA’s minute system provides the flexibility required to carry out the specific terms of the treaty despite changing circumstances. In addition to collaborating on large joint public works projects required by the treaties, the commissioners of the IBWC and CILA are tasked with identifying new or anticipated boundary or water problems and making recommendations to their respective governments. Once agreed upon by the commissioners, the recommendations are embodied in the form of minutes. These minutes are written in both English and Spanish, signed by both commissioners and forwarded to both governments for approval. Upon approval from both, the minutes become binding obligations of the United States and Mexico. The most recent relevant minute, Minute 325, ended the standoff in Ojinaga in 2020 through a transfer of water owned by Mexico and already stored in border reservoirs, though in reality it provided only a temporary stop-gap solution while a longer-lasting determination could be sought. Rightfully described as “an accounting move,” it nonetheless contained the seeds of a more substantial response. In addition to transferring ownership of water on a balance sheet, Minute 325 more significantly also stated an intent to establish a Rio Grande Hydrology Work Group and a Rio Grande Policy Work Group to oversee the work of the Hydrology Work Group. Experts from both countries would participate in the work groups with several forward-looking goals to “enhance information exchange, develop a binational Rio Grande model, and use the model as a tool to analyze water management scenarios, including scenarios related to future water conservation projects.” The Commissioners then set a target date of December 2023 to develop a new minute that would provide increased reliability and predictability in Rio Grande water deliveries to users in both countries.

The second crucial treaty was the Agreement Between the United States of America and the United Mexican States on Cooperation for the Protection and Improvement of the Environment in the Border Area (known as the La Paz Agreement) which was signed in 1983. This treaty created a framework for cooperation between the Environmental Protection Agency in the United States (EPA) and the Secretaría del Medio Ambiente y Recursos Naturales (SEMARNAT) in Mexico. The most recent joint collaboration under the La Paz Agreement is a five-year (2021–25) program called Border 2025. The stated purpose of the Border 2025 program is “to protect the environment and public health in the U.S.-Mexico border region, consistent with the principles of sustainable development” within the framework of the respective laws and regulations of the United States and Mexico. It follows two earlier similar programs, Border 2020 and Border 2012. Prior to Border 2012, Border XXI included the “first binational attempt to develop environmental indicators for the border region.” Border 2012 then mandated the development and use of these indicators to measure progress in the areas of air, water, and land contamination; environmental health; chemical exposure via accidental release and terrorism; and compliance, enforcement and environmental stewardship. Stakeholder involvement was also important in the implementation of Border 2012, though it was generally limited to governmental and non-governmental organizations. Years of effective collaborations followed, and today, the implementation of Border 2025 is coordinated by policy workgroups, task forces, and regional coordinators, which hold highly publicized open meetings intended to broaden the base of stakeholder input.

Understanding how the mechanisms contained within the two treaties have allowed a cooperative relationship between the two countries to flourish is potentially of great benefit to the many countries currently working to resolve similar issues. A 2018 study by the European Commission’s Joint Research Centre (JRC) identified several “hotspots” for potential future water wars. Five of the sites—the Nile, Ganges-Brahmaputra, Indus, Tigris-Euphrates, and Colorado rivers—share important commonalities with the Rio Grande. Like the Rio Grande, each of these rivers is in an area where access to freshwater is highly coveted, and each is located on a transnational boundary. The minute system of the 1944 Treaty and the environmental collaborations initiated by the La Paz Agreement are valuable tools that provide the built-in flexibility and adaptability needed for peaceful resolutions of unanticipated problems. These tools are not only worth keeping they are worth emulating.

III. Diving Into the Problem

Despite the temporary respite provided by the 2020 water transfer initiated in Minute 325, if serious stakeholder concerns are not addressed in the planned minute, future conflict regarding the allocation of water between the United States and Mexico is likely inevitable. Two of the most significant of the stakeholder groups are municipal/domestic users and agricultural interests; these two categories justifiably receive top priority under the 1944 Treaty hierarchy. With respect to the first category, population growth on both sides of the border has led to increased demand for domestic use. One report notes that the population in the binational border zone is growing faster than that in their respective states or nations. Within the second category (agriculture and stock raising) is likely found the greater opportunity for water conservation and improved processes because around seventy-five percent of all water withdrawals from the Rio Grande currently support agricultural purposes.

There are several additional important issues that remain unaddressed within the treaties. First, there is no mention of water preservation for ecological purposes within the 1944 Treaty hierarchy. The Rio Grande Valley is home to a dazzling array of biodiversity, including many endangered and threatened species, such as the ocelot, the jaguarundi, and the speckled racer. A national wildlife refuge exists in the lower Rio Grande Valley for the preservation of this biodiversity, and in Mexico, six different types of federally protected lands exist for similar conservation efforts. A sufficient, consistent water supply will be needed to maintain the wetlands areas in wildlife refuges in both countries.

A second potentially contentious issue is that a significant new user group is emerging in northern Mexico: the oil and gas industry. The U.S. Congressional Research Service noted in 2018 that “the use of water for hydraulic fracturing (fracking) as well as the disposal of wastewaters from oil and gas development may draw attention to border water quality protections and monitoring.” While the future use of fracking in northern Mexico remains highly contested, many fear that if fracking is widely permitted, it will have a detrimental impact on both the quantity and quality of water available for residential and agricultural use.

A third issue is that although the 1944 Treaty is explicit about the quantity of water that each country must deliver to the other, it says nothing about water quality. In the years following ratification of the treaty, this was a major cause of friction as Mexico took issue with the salinity levels in the water that the United States delivered from the Colorado River. A resolution to the salinity dispute was finally attained in 1973, and the terms of the agreement were concretized in Minute 242. Despite the eventual successful negotiation of Minute 242, it was not achieved quickly nor without external pressure.

IV. Steps to Future Success

Notwithstanding the apparent weaknesses, the two treaties have created a surprisingly resilient and stable framework for the United States and Mexico to work together to discover new answers as new challenges arise. Minute 325, despite its usefulness in averting the immediate crisis in 2020, was never intended to provide permanent, thoughtful change. Recognizing that needed reforms would require discussion and input from many stakeholders, the commissioners set a goal to develop a minute by December 2023 that would provide increased reliability and predictability in Rio Grande water deliveries to users in the United States and Mexico. They also provided a means for sharing operational information between the two countries in the interim. In anticipation of the upcoming 2023 deadline, the IBWC commissioned a report entitled “The Rio Grande/Rio Bravo Water Deliveries Under the 1944 Treaty: A Compendium of Ideas.” A brief survey of some notable ideas from the study may be useful. Stakeholders interviewed in the development of the report identified four possible opportunities for positive change: (1) the creation of multiple additional venues for interaction among the parties and stakeholders and an expanded base for participation; (2) changes in water management designed to promote certainty and sustainability; (3) expansion of the water supply in both Mexico and the U.S, supported by programs, conservation, and funding; and (4) the implementation of environmental solutions for the Rio Grande. An examination of each follows below:

A. Create Multiple Additional Venues for Interaction among the Parties and Stakeholders, and Cast a Wide Net for Participation

Inclusion of an ever-expanding diverse group of participants should be expected to lead to an abundance of unique insights and proposals for future action steps. The creation of this report is itself an example of this principle in action. To compile the “Compendium of Ideas” in the paper’s title, the author interviewed fifty-five stakeholders in the United States and Mexico in 2022, including current and former officials and representatives from federal and state governments, water districts, irrigation districts, academia, and non-governmental organizations, lawyers, and scientists. But achieving greater levels of stakeholder participation and transparency may be easier in the United States than in Mexico due to several factors. One of these is the decentralized approach to water management in the United States that means that the United States cannot effectively operate any water management projects without stakeholder participation. Another factor is that water districts and utilities in the United States provide an excellent opportunity to develop locally-driven innovations in water management and technological implementation. Recognizing that in the land of extremes that is the Rio Grande basin, it is as necessary to plan for floods as for droughts, another report proposes that a consideration of flood risk “should include expanded community engagement to convey information about risks as well as adaptation options at the community level.” The same report also proposes expanding the existing USIBWC Citizens Forums to become truly binational in the future.

In Mexico, a centralized approach to water management has had the opposite effect. “Since the vast majority of domestic water-management decisions are made by the country’s federal water agency, CONAGUA, at the national level, local communities have little to no real opportunity to be involved in meaningful decision-making.” Still, one expert suggests that the dominance of water issues in Mexico City could lead to greater political will to address the issues in Mexico.

B. Make Water Management Changes to Promote Certainty and Sustainability

As of today, no broad bilateral agreement exists on U.S.-Mexico border groundwater management and use. Because of the degree to which groundwater supplements surface water in the border region, it makes sense to include groundwater management in any future water management plans. Despite the significant function of groundwater supplementation, water stored in aquifers generally is not addressed by the U.S.-Mexican binational water-sharing agreements. One expert correctly notes that “this is an issue that will require revision of the legal framework in all jurisdictions.” This particular challenge is not one that can be resolved quickly due to the differing ways states and countries manage groundwater—including ownership. Nonetheless, it is necessary to make the effort to work toward groundwater sustainability because of the total dependence that some border communities have on groundwater.

C. Expand the Supply of Water in Mexico and the U.S. with Programs, Conservation, and Funding

Water supply and demand are on a collision course, and any solutions will require time and resources to implement. So far, the dominant strategies for augmenting and diversifying water sources along the border have been the development of more efficient irrigation conservation technologies and wastewater reclamation processes, but other conservation opportunities remain generally unexploited. Expanded use of “green infrastructure” in urban planning is one means by which rainwater that might otherwise flow directly into drainage or sewage systems could be preserved as groundwater. Additionally, rainwater harvesting systems present promising technological solutions, especially if expanded to commercial and industrial facilities. Already common in residential use, these systems have the potential to greatly reduce the strain on freshwater availability.

D. Implement Environmental Solutions for the Rio Grande.

Cooperative efforts have expanded greatly in the forty years since the La Paz Agreement was signed, and one would expect that water use for ecological preservation purposes will receive greater attention in the future. The Environmental Protection Agency (EPA) in the United States and Secretaría de Medio Ambiente y Recursos Naturales (SEMARNAT) in Mexico were charged with carrying out activities in accordance with the La Paz Agreement. In addition to the EPA/SEMARNAT partnership, a number of partnerships between states already exist for the purpose of addressing water quality issues, and these partners would do well to bring their concerns and research to the IBWC/CILA for inclusion in the upcoming minute.

V. Conclusion: “If It Ain’t Broke, Don’t Fix It.”

In recent years, some interested parties have raised the question whether the 1944 Treaty may have outlived its usefulness, and they suggest that amending the treaty terms is now necessary. The Congressional Research Service (U.S.) noted in 2015 that “some U.S. stakeholders support reevaluating the current binational water-sharing framework for multiple reasons, including Mexico’s Rio Grande water deliveries, its reservoir management and plans, and other disputes and concerns (e.g., environmental restoration and protected and invasive species management issues) in both the Rio Grande and Colorado River basins.” While certain stakeholders may have openly suggested that amending the 1944 Treaty may be necessary in the face of changing water needs, this action is unwarranted because once a minute is approved, it functions as a legally enforceable amendment to the Treaty. Others disagree. Gabriel Eckstein of Texas A&M University opines that “the minutes are actually interpretations or clarifications of the treaty, not amendments to it.” Still, he notes the benefit of the system to offer “opportunities for innovative and flexible solutions to adapt to changes and address situations such as: growing populations, increased economic development, water quantity changes, climate change, etc.” Work group and stakeholder discussions in anticipation of the upcoming 2023 minute will undoubtedly draw attention to many conflicting interests, complex challenges, and contrary opinions. These debates between newly acknowledged competing stakeholders over the terms of the upcoming minute should be welcomed as indicators that the treaty continues to function exactly as it should.