McALLEN (Texas) -- Sonia Lambert gazed out at an open-air canal carrying mud-green water from Rio Grande to nearby villages and farms, much of which is lost to evaporation or seepage.
Lambert stated, "That will become someone else's problem," referring to Lambert's upcoming retirement as the head of an irrigation district close to the U.S.-Mexico border.
A canal system that was built more than 100 years ago to supply water to Rio Grande Valley's rich farmland and rapidly-growing cities still supplies water. Experts say that the canals are losing as much as 40% today, which could lead to severe water shortages in the future as more people move to the region and the climate changes.
Guy Fipps, an irrigation engineer at Texas A&M University, said that as the region becomes drier, water supplies will decrease greatly. He has been studying the water system since 1998.
According to state water officials, the demand for water will more than double in the next 50 year. McAllen has been growing at an incredible pace for decades. Newcomers were drawn to the large free-trade zone, which offers jobs in retail, health care, and education. According to the U.S. Census Bureau, McAllen's population grew sixfold between 1990 and 2020. Similar results were seen in Mexico's cities of Matamoros and Reynosa, which grew after U.S.-owned assembly plant establishments were made in the mid-1990s.
A 1944 treaty between Mexico and the U.S. that governs how the two countries share water from Rio Grande complicates matters further. Mexico is required to send 350,000 acre feet of water each year to the U.S., enough to supply 700,000. households. It has repeatedly failed to fulfill these obligations due to drought, water shortages, and a dry crop industry in northern Mexico.
Late deliveries can be frustrating, but U.S. water managers and farmers are quick to recognize a major problem at home: The leaky canal system. This has been long considered too costly to fix by both local and state officials.
There are more than 2,000 miles (3.219 km) of pipes and canals in the region. These can be used to deliver large quantities of water to farms. Many districts have tried to improve the efficiency of waterways by lining them with concrete or monitoring farms' water usage with meters. The other option is to replace canals with underground pipes, which are less likely to lose water and better suited for serving cities.
Lambert, who is the Cameron County's irrigation district manager, stated that it costs between $250,000 to $1 million to convert a mile of open air canal into underground pipes. She said that only a fifth of the district's 250 miles (402 km) of canals have been converted underground over the past 20 years.
Lambert stated, "It just becomes an amount that cannot be supported by the farmer community."
Fipps said that canal repairs are often funded by the higher rates city water utilities pay. This has meant that water districts that serve larger cities have made greater progress in bringing the canals up-to-date.
The Rio Grande Valley's water utilities are still connected to the same aging system.
Because cities and farms both get water from the same canals and hydrologists and water officials warn that the Rio Grande's declining flows and low reservoir levels could spell trouble for everyone during a prolonged drought. A canal with less water will lose more water to seepage or evaporation. Everyone's water supply is at risk.
Experts already believe that the demand for water from this river is greater than its supply.
Smaller towns that receive very little water could be particularly affected by severe droughts. Their irrigation districts may not have the funds to replace or repair canals.
Fipps stated, "This is an unusual circumstance, that the agricultural cans are used to deliver the municipal water."
Experts predict that the region's farmers will experience a worsening drought and have to make harder choices over time. This is already happening in other parts of the American West. Some irrigation districts have been able to receive federal or state funding over the years through grants administered by Bureau of Reclamation. However, water managers, farmers, and hydrologists feel that the money is not sufficient for complete fixes. According to the Texas Water Development Board, water used for irrigation in Rio Grande Valley farms will drop by 36% by 2070. This is due in large part to more urbanization.
Lambert already sees glimpses of the future in rural Cameron County. Lambert informed sugarcane farmers of her district earlier this year that they would only receive one water delivery, even though it had rained heavily.
Some farmers purchased water from nearby districts to save their crops. This cost them tens or thousands of dollars. Some farmers removed more than 100 acres. A few weeks later, the skies cleared.
Lambert often can't give a precise answer to farmers who ask for water amounts for the coming season.
"That's the million-dollar question that our farmers ask. She said, "And I have no earthly clue."