1944 Water Treaty deliveries to United States by Mexico
By Sonny Hinojosa
Water Advocate
Last Wednesday, Oct. 25, marked the end of the third year of a five-year treaty cycle.
The United States receives one-third of the flow reaching the Rio Grande from six named Mexican tributaries that flow into the river above the Amistad and Falcon international reservoirs. The third of the flows shall not be less — as an average amount in cycles of five consecutive years — than 350,000 acrefeet annually.
The target delivery volume as of Oct. 14, was 1,040,411 acre feet. As of the same date, Mexico had delivered 372,401 acre feet. However, Mexico is behind 668,010 acre feet to the U.S. (almost two years worth of water). The U.S. State Department believes Mexico has the full five years to deliver the 1,750,000 acre-feet (350,000 acre-feet x five years) and need not deliver an annual amount. Mexico continues to gamble on a storm to fulfill its delivery requirement to the U.S.
In August 2022, a rain event arrived from the Gulf of Mexico at the mouth of the Rio Grande. The rain followed the river all the way into the Big Bend region of Texas before curving southwest into Chihuahua, Mexico.
That storm, plus the monsoon season in the succeeding months, brought substantial rain to Mexico. The country gained 2.2 million acre feet of water in the tributaries that the U.S. is supposed to receive onethird of the flows from. Their storage in the six tributaries just fell shy of 3 million acre feet.
Yet, no deliveries were made to the U.S.
The U.S. received one-third of the flows that fell below the lowermost dams in the six tributaries that Mexico couldn’t capture.
When the treaty was signed in 1944, Mexico had three reservoirs in the six tributaries. Since that time, Mexico has constructed eight additional reservoirs. In essence, Mexico is capturing the water that used to flow into the Rio Grande, storing it, and utilizing it to expand their farming. Mexico is farming desert with water that should flow into the Rio Grande.
In the meantime, the U.S. has 21.28% (718,538 acre-feet) of the water it could store in the Amistad/ Falcon reservoir system. Texas is the beneficiary of the nation’s share of water. As an annual average, we consume 1.1 million acre feet. The agricultural sector has suffered immense losses.
Most of the irrigation districts in the Rio Grande Valley have been curtailing the use of irrigation water to their farmers for the past two years. Currently, three in the Rio Grande Valley and one in the Eagle Pass area have ceased delivering irrigation water due to the low supply.
We will have to wait and see what the weather does to alleviate this water supply shortage. Mexico has two more years in this Treaty cycle to comply with the deliveries of water to the U.S. and no incentive to release water in the meantime.