El Rio Not-So-Grande

Here at the tip of Texas, the southernmost point of the Mexican border, leaving the United States has never been easier. Just stroll down Boca Chica Beach, a remote stretch of beach and dunes surrounded by miles of brush and cactus. After a couple of miles you'll notice that all of the cars parked out by the surf have Mexican license plates. Congratulations: you've just walked straight into Mexico.

Of course, it's not supposed to be this easy. A huge delta should be in the way, the mouth of the second longest river in the United States, in fact. But the Rio Grande is gone, sapped completely dry by the thirsty farms and cities of northern Mexico and southern Texas. In its place is a wide sandy beach and a short section of orange nylon fencing erected by U.S. Border Patrol agents, an only partially successful effort to stop wayward American tourists from accidentally wandering right out of the country.

When Spanish explorer Alonso Alvarez discovered the Rio Grande in 1519, the river's mouth was more than 30 feet deep and Alvarez sailed nearly 20 miles up the river without running out of room to tack his four unwieldy ocean-going vessels. As late as 1907, steamships carried passengers and cargo as far as Roma, 100 miles inland, while river cities like Brownsville and Matamoros were thriving ports. But now all that's left at the mouth of the 1,885-mile Rio Grande is a still and shallow lagoon of algae-green water that stops several hundred yards from the ocean surf.

Over the past 30 years, the Lower Rio Grande Valley has experienced explosive growth in just about everything: population, industry, commerce, tourism, and agriculture. It's the center of the NAFTA-driven border economy, the site of Mexico's largest concentration of export-oriented factories -- or maquiladoras. It's also home to many of the fastest growing cities in both countries; the valley's total population has doubled to more than 2.2 million since 1970, and is expected to double again by 2030 as more Mexicans move here from the interior in search of work.

But amidst the growth, planners overlooked an important fact. The valley, geographically speaking, is one step away from being a desert: a hot, dry, subtropical plain where dryland brush competes with prickly cactus for the little water that falls here. Groundwater supplies are brackish and unhealthy. The Rio Grande once made the lower valley an oasis, providing virtually the only source of water for people, crops, industry, and wildlife. But as the border region has grown, the river has not, and people on both banks have a big problem on their hands.

"It's a semi-arid region and the availability of water has always been a constraint on development," says economist Mitchell Mathis, a senior researcher at the Houston Advanced Research Center in The Woodlands, Texas who directed a comprehensive international study on the lower Rio Grande basin. "They've run up against a wall in terms of having enough water to satisfy everyone."

Concerns about how unparalleled growth would affect an arid region were shoved under the rug at the NAFTA negotiations.

When the North American Free Trade Agreement was negotiated, the governments committed to improving sewage treatment in the region, but water use and supply issues were largely ignored. "The public interest community raised concerns about how unparalleled growth would affect an arid region, but they were just shoved under the rug at the NAFTA negotiations," says Mary E. Kelly, director of the Texas Center for Policy Studies in Austin. "If there's a silver lining to the drought it's that it's brought a sense of urgency to these issues."

One Big Drought

Indeed, the weather is the most immediate problem. Across the Rio Grande's drainage basin it just hasn't been raining. Drought isn't unusual in the here. For many decades the river has run completely dry most summers as it passes through the desert south of El Paso, 800 miles from the Gulf. Normally it would be replenished by the Rio Conchos, which flows into the Rio Grande from the arid ranchlands of Mexico's Chihuahua state. But an eight-year long drought has reduced the Conchos' flow. Meanwhile, farmers, irrigators, and industrial parks clamor for ever-scarcer river water.

As a result, the enormous international reservoirs downstream have fallen to some of their lowest levels since they were constructed four decades ago. Mexico's share of the water in the Amistad and Falcon reservoirs -- the massive artificial lakes that provide water to the farms and cities of the lower valley -- is only 13 percent of the normal conservation level; the U.S. share is less than a third. Water levels at Falcon are so low that Guerrero, a Mexican town submerged when the reservoir was created in 1953, is again high and dry.

There just isn't enough water to go around in the lower valley. By the time it reaches Matamoros, the river level is so low it often falls below the intake pipes that provide water to Mexico's second-fastest growing city, forcing rolling water cut-offs. Farmers on the Texas side of the lower valley estimate the area has lost $400 million annually due to the scarcity of irrigation water. "With the reduced [water] allocations, growers are having to plant fewer and fewer acres," says soil scientist Bob Wiedenfeld of Texas A&M University's agricultural research station in Weslaco, a farming community in the lower valley. "They're comparing this to the great drought of the 1950s here in Texas, and in Mexico it's even worse than that."

Lower valley farmers on both sides of the border blame the Mexican government for the severity of the situation. Under a 1944 treaty, Mexico is required to deliver 350,000 acre feet of Rio Conchos water annually to the Falcon-Amistad reservoirs, two-thirds of which is earmarked for use by downstream Mexicans, one-third for lower valley Texans. The system worked fine back in the 1960s and 1970s, when there was little industry and less than half as many people in the basin. But with the current drought, the treaty mechanism has come unglued. With water in scarce supply, authorities in Chihuahua have refused to release precious water from their smaller reservoirs high up in the Rio Conchos basin. Mexico now owes the lower valley a staggering 1.5 million acre feet of water, more than the current contents of the Falcon and Amistad reservoirs combined.

Mexico argues that the water simply isn't there to give. "We've always said that in the end we will comply with the treaty, but the Mexican government is incapable of making the skies rain," says Mexico's water negotiator Alberto Szekely, a Mexican Foreign Ministry advisor. "We're being accused on both sides of the border of not giving water, when really it is nature that is denying it to us."

The United States disagrees, pointing to the fact that water that should have been released to downstream users was instead allocated to irrigation in Chihuahua, in violation of the 1944 treaty. "There was some water that could have been released and was not," says Sally Spener, spokesperson for the U.S. office of the International Boundary and Water Commission in El Paso. "Water should be released to meet treaty obligations before it is used for upstream irrigation," she says. Meanwhile, the ecosystem has started showing the wear-and-tear, threatening important industries.

One affected industry is commercial fishing. White shrimp, blue crabs, sea trout and other fish require brackish water to reproduce, and the mouth of the Rio Grande was one of the few places they could find it. "When there's a sand bar there the small shrimp can't get out and the [breeding] shrimp can't get in," says Walter Zimmerman, who owns 23 shrimp trawlers in Port Isabel, Texas. Cameron County marine agents report dramatic reductions in the shrimp, crabs, and other marine species in the lower river.

"We're losing commercial opportunities."

The south Texas coast has become a popular tourist destination, and many come for recreational fishing, but Zimmerman says the Rio Grande's woes are hurting that, too. "If you don't have these nursery areas then you won't have fish and shrimp, so why would people come down here? We're loosing commercial opportunities," he says.

The $100 million ecotourism industry is also threatened. The region is on both major migratory bird flyways and attracts large numbers of bird watchers from across the country. But the birds depend on tiny enclaves of surviving wetland and brush forest habitat that are suffering from a lack of water. "We're putting in less water and more pollutants, which creates a big problem" for aquatic life, says Salvador Contreras, emeritus professor of ichthyology at the Universidad Autonoma de Nuevo Leon in Monterrey, Mexico.

An Ever Bigger Challenge

But even if the drought ends, the Lower Rio Grande Valley faces a serious water supply challenge. As the region's population doubles over the coming quarter century, the water supplies reaching the area are likely to shrink. Upstream cities like Monterrey are expected to mushroom as more people move from the interior to work in export-oriented industries. "There will be more and more demands for water," says Mr. Mathis, who directed the Rio Grande basin study. "We're going to have to do a much better job managing the water we have."

When the 1944 water regime was crafted, the population was less than 600,000 and agriculture was the only show in town. Great dams were built, ensuring growers a consistent supply. Over the long-term there appeared to be plenty of water to meet the region's relatively modest needs, and little attention was paid to how it was used. Even today some of south Texas' irrigation flows through open ditches (as opposed to sealed pipes) and most is distributed by simply flooding the fields rather than with sprinklers or drip systems. In Mexico, an estimated 30 to 50 percent of irrigation water is lost to evaporation and leakage in such channels. The solution is for agriculture, which uses more than 80 percent of the lower valley's water, to do more with less.

Mr. Mathis' study showed that just a 10 to 20 percent reduction in irrigation demand would allow the region to meet all its water needs in 2030. That's technically feasible, but will require some innovative thinking. New irrigation systems can reduce leakage, but cost a great deal. Mathis thinks many cities may find that the most cost-effective way to meet rising water demand is to help farmers buy the water-saving technologies in return for the water saved. "That would be a win-win situation, but it's going to be difficult to get cities to come around to the idea."

Water managers on both sides of the border will need to recognize the importance of allocating water for the natural ecosystem. Not only is it important to fishermen and tourism, it's essential to keeping water purification costs down. That's because the Rio Grande also serves as the main wastewater canal for the region's growing cities, and reduced flow means increased concentrations of pollutants, sometimes requiring expensive water treatment before it can be reused. "There may be more economic value to leave the water in the river to maintain quality than there is to release it for irrigation," says Mathis.

But for any of this to work, Mexico will have to stand by its treaty commitments as much as possible. Irrigators in Texas' lower valley have already drawn up a plan to improve efficiency over the next 30 years, but that assumes that Mexico will stand by its treaty commitments. "If we can't rely on the Mexican water," says McAllen, Texas lawyer Glenn Jarvis, chairman of the regional water planning group, "then the [irrigation] shortages would be so great that there aren't any economically-viable means to address them."

Colin Woodard is the author of Ocean's End: Travels Through Endangered Seas. He currently lives in Port Isabel, Texas.