By Sarah Kirkle, TWCA
Background. In 1944, the U.S. and Mexico signed a treaty governing the distribution of water that flows in the Rio Grande from Fort Quitman, Texas to the Gulf of Mexico. Under the treaty, the U.S. is allotted one-third of the water flow reaching the main channel of the Rio Grande from six tributaries: the Conchos, San Diego, San Rodrigo, Escondido, and Salado Rivers and the Las Vacas Arroyo. This one-third portion must be at least 350,000 acre-feet per year (1,750,000 acre-feet total) as an average amount in cycles of five consecutive years.
The current five-year cycle began onOctober 25, 2015, and will conclude onOctober 24, 2020. The five-year cycle can be reset at any point that the U.S. conservation capacities in both international reservoirs (Amistad and Falcon)are filled with waters belonging to the U.S. Mexico has exceptions from the water delivery requirements of the treaty for extraordinary drought or an accident to their hydraulic system.
The U.S. International Boundary and Water Commission (USIBWC) is the governmental entity responsible for overseeing, enforcing, and settling any differences in application of the various boundary and water treaties between the U.S.and Mexico.
Current Water Shortage. As of early March, Mexico has delivered 1,275,889 acre-feet (73%) of 1,750,000 acre-feet allotted to the U.S. in the five-year cycle, according to TCEQ. Mexico has another six months to make up the deficit of 474,111 acre-feet. Mexico is not experiencing extraordinary drought or hydraulic accidents that would prevent it from delivering on its water obligations to the U.S.
Recent Events. As the end of the five-year cycle nears, U.S. IBWC Commissioner Jayne Harkins has begun discussions with Mexico about the water deficit. While Mexico informally agreed in a December 2019 meeting to provide 180,000 acre-feet to the U.S. by the end of February, Mexico delivered less than 16,000 acre-feet, well below the agreement. Last week, as Mexican officials began to release water to the U.S., Mexican farmers protested out of fear of not having enough water for their own crops. Mexico halted the water releases in response to the protests. This is not the first five-year cycle in which Mexico has fallen into a deficit in delivering water to the U.S. In fact, the preceding five-year cycle ended in a deficit. When a five-year cycle ends in a deficit, the deficiency must be made up in the following five-year cycle, in addition to water required for delivery in that cycle. Should Mexico fail to deliver the balance of the minimum water contribution to the U.S. by October 24, it would again be in violation of the treaty.
Impacts. Stakeholders are concerned about the impact the water shortage has on the range of water users in the Lower Rio Grande Valley, from municipal drinking water to farming operations, as well as the continued violation of the treaty and what that means for future cycles. As a large portion of the Lower Rio Grande Valley is already experiencing drought, the impacts of this water shortage could be exacerbated through the coming months if drought continues.
Next Steps. USIBWC will continue to monitor Mexico's actions and negotiate to satisfy Mexico's water obligations to the U.S. by the October deadline.
Related: See USIBWC Commissioner Jayne Harkins’ presentation from the March 2020 TWCA Annual Convention.