This essay is written by Regina M. Buono, Principal at Aither, and Gabriel Eckstein, Professor of Law at Texas A&M University, and director of the International Water Law Project. It first appeared on the Global Water Forum on September 28, 2022.
The Rio Grande River, known in Mexico as the Río Bravo, is one of the principal rivers in the southwestern United States and northern Mexico. Originating in Colorado in the U.S., the Rio Grande flows over 3,000 kilometers to the Gulf of Mexico. Its basin covers an area over 500,000 square kilometers. Governing such an important transboundary water system poses a multitude of issues, and the most recent treaty guiding such efforts is now almost 80 years old. Regina Buono and Gabriel Eckstein discuss here the big challenges facing the Rio Grande/Río Bravo Basin, and how effective the current governance arrangements are.
The Rio Grande flowing through a national park in Texas, U.S. The Rio Grande/Río Bravo Basin ties two nations together through shared natural resources, wildlife habitats, socio-economic systems, culture and history. Governing this transboundary system is an enormous challenge. (Image by David Mark from Pixabay)Mexico and the United States have shared the Rio Grande river basin (known as the Río Bravo in Mexico) for over 170 years. Though the basin includes over 2,000 kilometers of international border, it also ties the two nations together through shared natural resources and wildlife habitats, socio-economic systems, and cultural and historic bonds.
Management of the Rio Grande and its tributaries is governed by a series of border treaties and institutions, as well as the domestic national and state laws of the two countries. The most recent and visible border treaty is the 1944 Treaty on the Utilization of Waters of the Colorado and Tijuana Rivers and of the Rio Grande, an agreement often lauded for enabling innovative and collaborative governance of the three named rivers.
In recent years the treaty regime has come under intense pressure. Domestic and international water governance institutions are struggling under the strain of climate change impacts, population growth, and the attendant impacts to water supply and demand in the region. Three issues are of particular concern: (1) an increasing focus on groundwater and groundwater-surface water interactions and the related practical and policy implications; (2) strained relations between the two treaty parties, as well as with local and regional stakeholders; and (3) resolution of Mexico’s water debt under Article 4 of the 1944 Treaty and the need to facilitate increased reliability and predictability in Rio Grande water deliveries.
Groundwater, a crucial resource long neglected and little understood
Groundwater has long been neglected by the Mexico-US transboundary water regime. Groundwater plays a significant role in agricultural production, economic development, and even the social fabric of the region, but the estimated 72 transboundary aquifers and hydrological units have only sporadically been studied and are excluded from the existing treaty regime. Groundwater supplies, which constitute essential water sources for millions of people on both sides of the border, are managed under independent, domestic legal regimes in each country. Moreover, there are no procedures or mechanisms to integrate hydrologically related groundwater into the overall management and allocation regime of the Rio Grande.
To address this disorder, a key first step is to collect existing information on groundwater-surface water relationships in the basin, and to fill the significant knowledge gaps with additional research. It’s also important to expand the existing system for data and information sharing to include groundwater resources and facilitate more opportunities for public participation by local stakeholders in the governance system, since groundwater—more so than rivers and lakes—is regarded as a local resource. Finally, the management and governance of transboundary aquifers should be pursued collaboratively by local and regional stakeholders on both sides in a manner that allows full engagement and collaborative decision-making.
Governance across borders
The binational institution responsible for managing Mexico-US border waters is the International Boundary and Water Commission (IBWC/CILA). Its current approach to managing the Rio Grande, which offers limited stakeholder involvement, has been heavily criticized, especially as more integrated and inclusive management approaches have proliferated elsewhere around the world.
Stakeholder participation and transparency are relatively more advanced in the U.S., in part, a function of that country’s decentralized approach to water management, which requires local participation to operate effectively. Stakeholder engagement in the U.S. also benefits from the greater availability of resources for state-level administrations and agencies that support the development and administration of local and regional water plans, as well as from efforts by private and civil society groups.
In contrast, stakeholder participation and transparency on the Mexican side is largely absent because of the country’s centralized approach to water management. 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. The eventual effects of these enduring conditions became apparent in the summer and fall of 2020 when Mexican farmers in the state of Chihuahua protested water deliveries from the Rio Conchos, Mexico’s chief tributary to the Rio Grande. The protests were a poignant symptom of the disenfranchisement of local water stakeholders in that country.
Mexico’s water debt under the 1944 Treaty
Under the 1944 treaty, Mexico is obliged to deliver to the U.S. an average annual 350,000 acre-feet of water down the Rio Conchos and into the Rio Grande. The treaty allows Mexico to carry over any incomplete balances of water from one 5-year cycle to the subsequent 5-year cycle in the event of an “extraordinary drought.” The two countries, however, have historically disagreed over the meaning of “extraordinary drought” and whether repayment of a water debt can be carried forward over more than two consecutive 5-year cycles (Carter et al. 2017). By the Fall of 2021, Mexico had accumulated a significant water debt and was poised to begin a third 5-year cycle in arrears.
On October 21, 2021, three days before Mexico would have violated its delivery obligations, IBWC/CILA signed an agreement to resolve the issue. Under Minute 325, Mexico fulfilled its delivery obligations by transferring the entirety of its water in the Amistad and Falcon reservoirs to the U.S. While the transfer nearly depleted all of Northern Mexico’s stored water in the reservoirs, in doing so, Mexico abided by the 1944 Treaty and ended the 2016-2020 cycle debt free (Helfgott 2021). The minute also resolved the long-standing disagreement over Mexico’s ability to end two back-to-back cycles, stating that two successive cycles “may not end in a deficiency.”
Minute 325 also recognized the importance of two pre-existing working groups, the Rio Grande Hydrology Work Group tasked with developing technical information on the Rio Grande, and the Rio Grande Policy Work Group, which oversees the Hydrology Work Group and “consider[s] water management policies in the basin.” The two groups are now tasked with developing a new minute by December 2023 to provide “increased reliability and predictability in Rio Grande water deliveries to water users in the United States and Mexico” (IBWC 2020, ¶4).
Equitable, efficient and peaceful water governance
Though challenges remain, the 1944 Treaty’s mechanisms—and, in particular, the treaty’s minute system—have been shown to facilitate and support innovations in water management, and new efforts to improve sustainable management and public engagement in the Rio Grande basin are underway at various levels. As severe drought sets in across Europe, the American west, China, and other parts of the world—underscoring the need to allocate and manage water use equitably, efficiently, and peacefully—it is increasingly imperative that humans imbue water management systems around the world with these qualities.
This essay is a condensed version from the authors’ chapter on “Current challenges in the Rio Grande/Río Bravo Basin: old disputes in a new century,” which appears in Water Resources Allocation and Agriculture: Transitioning from Open to Regulated Access, (Josselin Rouillard, at.al., Eds., Edward Elgar 2022), available at https://doi.org/10.2166/9781789062786.
References
Carter Nicole, SP Mulligan & C Ribando Seelke (2017). U.S.-Mexico Water Sharing: Background and Recent Developments, Congressional Research Services, R43312. https://fas.org/sgp/crs/row/R43312.pdf.
Helfgott Alexandra (2021). Bilateral Water Management: Water Sharing between the US and Mexico along the Border. Wilson Center. https://www.wilsoncenter.org/article/bilateral-water-management-water-sharing-between-us-and-mexico-along-border
International Boundary and Water Commission (2020). Minute 325: Measures to End the Current Rio Grande Water Delivery Cycle Without a Shortfall, to Provide Humanitarian Support for the municipal Water Supply for Mexican Communities, and to Establish Mechanisms for Future Cooperation to Improve the Predictability and Reliability of Rio Grande Water Deliveries to Users in the United States and Mexico. Available at: https://www.ibwc.gov/Files/Minutes/Min325.pdf