A River Runs Through It
Resolving the Rio Grande water dispute between the United States and Mexico
By Ruben R. Barrera and Dan A. Naranjo
In 2010, the world’s population was nearly seven billion and it is expected to reach more than nine billion by 2050.1 This population increase will, out of necessity, require the need to extend and wisely use all available resources. There is no resource more valuable and necessary for human survival than water. Thus, water will become more valuable as the population increases over time.2 The world’s population, however, does not exist in a vacuum. These populations are all part of a system of nations who, motivated by their own interests, have fought over land and water rights.
The United States and Mexico are no exception. Throughout history, the two nations have had their share of conflict on a variety of issues, including land control, colonization, and water sharing. Both agreed to recognize the Rio Grande as the boundary between Mexico and the U.S./Texas in 1848 under the Treaty of Guadalupe Hidalgo.3
The Rio Grande (also known as the Rio Bravo del Norte) begins in Colorado and flows through New Mexico into Texas, creating the fertile delta known as the Lower Rio Grande Valley, and ends at the Gulf of Mexico.4
The Treaty of 1848, however, did not address the sharing of water. Two agreements now govern the sharing of water between the United States and Mexico along the Rio Grande: the Convention of May 21, 1906,5 and the Treaty of February 3, 1944.6
The Treaty of 1944 states Mexico is to provide the United States “[o]ne-third of the flow reaching the main channel of the Rio Grande from the Conchos, San Diego, San Rodrigo, Escondido, and Salado Rivers and the Las Vacas Arroyo [(i.e., 6 tributaries)] provided that th[e] [one-]third shall not be less, as an average amount in cycles of five consecutive years, than 350,000 acre-feet . . . annually.”7 (Emphasis added.) However, “[i]n the event of extraordinary drought or serious accident to the hydraulic systems on the measured Mexican tributaries, making it difficult for Mexico to make available the run-off of 350,000 acre-feet . . . annually, . . . any deficiencies existing at the end of the . . . five-year cycle shall be made up in the following five-year cycle with water from the . . . measured tributaries.”8
Any five-year cycle can be shortened. “Whenever the conservation capacities assigned to the United States in at least two of the major international reservoirs, including the highest major reservoir, are filled with waters belonging to the United States, a cycle of five years shall be considered as terminated and all debits fully paid, whereupon a new five-year cycle shall commence.”9
Since 1944, Mexico has accumulated a water deficit at the end of a five-year cycle on three occasions. From 1992 to 2002, Mexico failed to deliver the minimum annual allocation of water—350,000 acre-feet—under the Treaty of 1944.10 The period from October 3, 1992, to September 30, 2002, involved two five-year cycles.11 Mexico ran a 1.5 million acre-feet deficit from 1992 to 2002.12 Ultimately, Mexico’s deficit of 1.5 million acre-feet from 1992 to 2002 was made up in 2005.13 The elimination of that deficit came about “through presidential intervention, negotiation of new minutes . . . investments in improved water efficiency” and “[h]urricaneinduced wet conditions.”14
The period from October 1, 2002, to July 12, 2010, involved one five-year cycle from October 1, 2002, to September 30, 2007, and three shorter cycles ranging from four months to one year and four months.15 The period from October 1, 2007, to July 12, 2010, resulted in shorter cycles because the conservation capacities assigned to the United States in the Amistad Dam and Reservoir and the Falcon International Reservoir, or Falcon Dam, were filled with waters belonging to the United States pursuant to the Treaty of 1944.16
In the last five-year cycle, beginning October 25, 2010, through October 24, 2015,17 Mexico began deliveries at a good rate in 2010; quickly fell behind in 2011 and 2012 (due to exceptional, extreme, severe, and moderate drought conditions); and increased water deliveries during 2013 and 2014 (since exceptional, extreme, severe and—to a degree—even moderate drought conditions subsided during 2014 and 2015) but still had a 263,250 acre-feet deficit by the time the cycle officially ended on October 24, 2015.18 The 263,250 acre-feet amount represented 15 percent of Mexico’s obligation.19 Some of the water delivered by Mexico during 2015 (i.e., roughly 100,000 acre-feet of water) came from sources that were not part of the Treaty of 1944.20
According to the United States Section of the International Boundary and Water Commission, or IBWC, Mexico’s 2010-2015 deficit of 263,250 acre-feet was made up starting in late 2015 and completed on January 25, 2016, during the new 2015 to 2020 five-year cycle.21
Juxtaposed against Mexico’s recurring deficits is the fact that the United States has not failed to fulfill its 1.5 million acre-feet water obligation to Mexico from the Colorado River under the Treaty of 1944.22
The language is clear that “[i]n the event of extraordinary drought or serious accident to the hydraulic systems on the measured Mexican tributaries,” the only way to make up “any deficiencies existing at the end of the . . . five-year cycle shall be” to make them up “in the following five-year cycle with water from the said [six] measured tributaries.”23 Regrettably, neither the term “extraordinary drought” nor “serious accident” was defined in the Treaty of 1944. Even more regrettable is that Mexico arguably views the United States’ water needs under the Treaty of 1944 on unequal footing with its own water needs.24 It has been reported that Mexico treats water deliveries to the United States as a secondary priority, and “high storage levels in some Mexican reservoirs” support this position.25 The fact the 2010-2015 water deficit was made up so quickly at the beginning of the new 2015-2020 five-year cycle seemingly indicates Mexico had the water and could have delivered it when it was due.
Why does Mexico continue to experience recurring water deficits? The answer is simple. The United States and Mexico fundamentally disagree on the interpretation of the Treaty of 1944. The United States believes Mexico is required to deliver 350,000 acre-feet of water annually over the course of a five-year cycle (unless Mexico is experiencing an extraordinary drought or has a serious accident to the hydraulic systems on the six measured tributaries). Conversely, Mexico believes it must only deliver the cumulative amount of 1,750,000 acre-feet of water by the end of the five-year cycle. Based on a cumulative and logical reading of Article 4 of the Treaty of 1944, it is reasonably arguable that the intent of the 350,000 acre-feet obligation is that it is to be an annual obligation. Presumably, the drafters realized that the annual 350,000 acre-feet of water would be needed and relied on every year by the Texas agricultural community, municipalities, and residents along the Rio Grande. No South Texas farmer, municipality, or resident can rely on a set amount of water every five years.
Farmers, municipalities, and residents along the South Texas border have been adversely impacted by Mexico’s recurring deficient water deliveries.26 The region has experienced job losses, millions lost annually in business activity (i.e., in excess of $600 million), and water shortages impacting thousands of residents in the Lower Rio Grande Valley (i.e., Cameron, Hidalgo, Starr, and Willacy counties).27
The current five-year cycle began on October 25, 2015, and will end on October 24, 2020,28 unless the cycle ends early if the conservation capacities assigned to the United States in the Amistad and Falcon dams are filled with waters belonging to the United States.29 According to IBWC data, the percentage of United States capacity at the Amistad Dam and Falcon Dam are 72.8 percent and 26.3 percent, respectively, as of September 2, 2017.30 Thus, there is no basis for ending the current five-year cycle early at this time. The IBWC data further reveals that Mexico is already behind in its water deliveries to the United States (565,867 acre-feet of water delivered vs. 670,273.96 acre-feet of water required as of September 23, 2017) in the current five-year cycle that began on October 25, 2015,31 and yet there are no exceptional, extreme, or severe drought conditions present.32 If you are a South Texas farmer, municipality, or resident, it is more important to receive consistent and predictable annual amounts of water in the current five-year cycle than erratic annual amounts of water made up in the next fiveyear cycle.
Since Mexico has and likely will continue to experience recurring water deficits both under the Treaty of 1944 and Minute 309 (i.e., a decision of the IBWC dispute resolution process) because of its interpretation of the Treaty of 1944, what options are available to address the recurring water deficits?
There are several options:
1. work within the IBWC dispute resolution process (culminating in decisions called minutes) since it is charged with settling disputes under the Treaty of 1944;33
2. if the minute dispute resolution process does not resolve the recurring water deficits due to the fundamental differences between the United States and Mexico in the interpretation of the Treaty of 1944, the United States commissioner of the IBWC could invoke the jurisdiction of the courts to prevent violation of the Treaty of 1944;34
3. continue senior level government official diplomatic discussions between the United States and Mexico leading to negotiation of an executive agreement;
4. negotiate a new treaty with Mexico that would clarify the annual 350,000 acre-feet requirement, the definition of extraordinary drought, use of water sources beyond the six tributaries, and numerous other water issues; or
5. litigate at the International Court of Justice, or ICJ, at The Hague, Netherlands, which addresses international grievances or arbitrate at the Permanent Court of Arbitration, or PCA. The ICJ is the ideal venue to resolve this complex water dispute. However, if the parties so choose, the PCA, a distinct entity from the ICJ, should be considered as an alternative. It is worth noting that pursuing litigation may lead to mediation, which could incorporate the negotiation of a new treaty.
The fact that Mexico is already behind in its water deliveries to the United States in the current five-year cycle should act as the catalyst to resolve this long-standing and important water dispute in a permanent way. Failure to do so has huge adverse impacts on farmers, municipalities, and residents all along the South Texas border. TBJ
This article was originally published in the January-February 2017 issue of San Antonio Lawyer and has been edited and reprinted here with the permission of the authors and the San Antonio Bar Association.
RUBEN R. BARRERA is a shareholder in Langley & Banack in San Antonio, where he focuses on municipal, municipal utilities, other local government, eminent domain, economic development, water, land development, use, and control law. He received his law degree from the University of Texas School of Law.
DAN A. NARANJO is a mediator and adjunct professor at St. Mary’s University School of Law. He received his law degree from the University of Texas School of Law.