It wasn’t too many years ago that the Rio Grande Valley (RGV) of Texas was an agricultural paradise. The first area-wide irrigation system was constructed in 1898, an engineering masterpiece, and it served as the foundation for the development of major agricultural operations across the region.

In the years that followed the region became well known for its abundant citrus and cotton production, and before long vegetable production spread across the Valley as well. Grain sorghum and sugar cane in more recent years have become popular crop choices, helping to sustain the area as a major agricultural production region even in modern times.

But this year, after two years of serious drought and other adverse water developments, several of the many irrigation districts that service the region have put farmers on notice that unless rains replenish diminishing reservoir levels soon, there will only be enough water to provide one irrigation application to commercial crops.

“The situation varies among the irrigation districts in the Lower Rio Grande Valley, but the larger districts have already advised farmers they will be limited to only one irrigation this season,” said Brad Cowan, Texas AgriLife Agriculture Extension agent in Hidalgo County. “Without substantial rainfall in the spring and summer our crops won’t thrive under those restrictions.”

While February and March are traditional planting times for cotton and grain sorghum, Cowan says commodity crop farmers are especially concerned about putting seed in the ground after being put on notice that irrigation water will likely be limited.

“It doesn’t matter if you are farming a citrus grove, a cotton field or are growing onions, being limited to just one irrigation isn’t encouraging if you are hoping for a good crop this year,” he added. “And it’s not just the farmers that are concerned. Several municipalities have been alerted that in two months they may not get all the water they are entitled to unless we get new inflows, either from water Mexico owes the U.S. or from rainfall in our watershed.”

Cowan said a recent meeting with National Weather Service meteorologists painted a grim forecast for measureable precipitation this summer, and the spring season. He said the Valley “seems stuck” between a recent La Niña weather event—the prime culprit responsible for the two year drought—and an expected El Niño weather event that has not yet formed, “if it does at all.”

Mexico's water debt

“And it’s not just the drought that is causing concerns over water shortages in the Rio Grande Valley. Mexico remains slow to release water into the Rio Grande from reservoirs across the border, an obligation they have as agreed in a water treaty,” said Cowan.

According to that treaty, Mexico is obligated to deliver water to the U.S. in cycles of five years. The current cycle began in October of 2010 and ends in October of 2015. During this period Mexico must pay the U.S. for rainfall in the Rio Grande watershed on their side of the border that was trapped in reservoirs and not allowed to flow into the river basin. By mid-February, Mexico had delivered just 403,082 acre-feet of water toward the five year total, which calls for a release of 1.75 million acre-feet of water.

Some local water activists quietly accuse Mexico of failing to meet their water obligations even though there are reports that at least one reservoir in Northern Mexico is running full.

The Rio Grande is the fifth largest river in North America. It runs North-South from its source in the Colorado Rocky Mountains to El Paso. From there it turns South-East and, for over 800 miles serves as the border between Mexico and Texas.

Due to intensive human development and water use in Colorado, New Mexico and West Texas, the Rio Grande runs dry South of El Paso during much of the year. As a result, the Rio Grande/Río Bravo (as it is called in Mexico) below Fort Quitman, Texas—just above Big Bend National Park—to the Gulf of Mexico has effectively become a separate watershed. Its climate is arid to semi-arid, and vegetation and wildlife consist of Taumalipan scrub and chaparral desert ecosystems. In spite of the semi-desert environment, the natural watershed on the Mexican side of the border is much larger than the watershed on the U.S. side.

Irrigation officials across the Valley say if Mexico would release a significant amount of the water they owe the U.S. by treaty, it could help replenish the two major reservoirs on this side of the border that serve the Rio Grande Valley, Falcon Lake reservoir and Amistad reservoir, effectively bringing relief to the forecast water shortage in the RGV.

The shortage has become a major regional issue in the Texas Valley in recent weeks. In mid-February, South Texas congressional members sent letters to Mexican officials and to officials of the International Border Water Commission, a bi-national organization operated by officials from both the U.S. and Mexico. Also receiving letters are members of the U.S. State Department.

Last week, members of the Lower Rio Grande Valley Water District Manager’s Association voted to send similar letters to the same recipients in hopes of initiating a positive reaction.

“In the RGV, irrigation districts contract with municipalities to supply them water, so this concern over shortages just doesn’t affect the agriculture sector but every Valley resident. If the drought continues for another year and no irrigation water becomes available, the prospect for a bad crop year is not only high, but unavoidable,” Cowan said. “And few folks are planting right now because they are waiting to see if March brings any saving rain.”

Already, water meetings are being organized across the Valley to keep government and industry on top of the latest developments, but the concern over rain and any delays on planting a new crop could well affect yields this year even if adequate timely rain should fall.