JUAREZ, Mexico -- On the outskirts of town, past block after block of pink and blue concrete shacks with barred windows, past dirt streets where kids on bikes dodge stray dogs searching for food, is a symbol of hope for this famously beleaguered border city: the Anapra wastewater treatment plant.

Built in 2006, the plant brought desperately needed sewage treatment to the Anapra community, whose residents had suffered high rates of waterborne diseases such as hepatitis A and shigellosis. The facility also helped stretch an overtapped water supply by providing treated wastewater to irrigate farms and parks and to spray dusty streets in a effort to improve air quality.

"The water is 100 percent reused, and we also use solar power," said Juan Manuel Herrera Mercado, a plant manager who led a tour of the facility Thursday for policy experts, hydrologists and others attending a U.S.-Mexico water resources summit.

The Anapra wastewater treatment plant, which treats wastewater so it can be reused on agricultural fields and parks, is part of the solution to the border region's water supply challenges. Photo by April Reese.

"We know that our concern for water -- the concern that both countries have for water -- is something that links us together and doesn't have to be something that separates us," said Roberto Salmon, Mexican commissioner of the International Boundary and Water Commission, which organized the conference.

The water treatment plant near Juarez, which has improved the quality of life for about 25,000 people, is an example of what collaboration between the two nations can achieve. But money for such projects is hard to come by on both sides of the border.

Part of the funding for the treatment plant came from a U.S. EPA program that provides matching grants for water infrastructure projects along the border. The agency finances the projects, which have to be approved by the Border Environment Cooperation Commission, through the Border Environment Infrastructure Fund, administered by the North American Development Bank.

Texas has completed several similar projects on the U.S. side, benefiting communities there and helping it meet state and federal environmental requirements. The projects also help implement the Border 2020 program, which aims to increase by 20 percent the number of homes connected to a potable water supply and wastewater collection and treatment systems (Land Letter, Nov. 17, 2011).

The Border Environment Infrastructure Fund, however, is increasingly underfunded -- at a time when water challenges in the border region are reaching a critical crossroads, water policy experts said.

"That funding has worked miracles all along this border," said Placido dos Santos, an analyst with the University of Arizona's Water Resources Research Center. "All of this collaboration is really important."

While the Border Environment Cooperation Commission estimates that $1 billion is needed to address water infrastructure problems along the 2,000-mile border, Congress typically allocates only up to $10 million a year.

No water, no growth

The cities along the border share ecosystems, including waterways, aquifers and airsheds. Officials and researchers on both sides of the border increasingly have come to understand the importance of working together to solve their shared resource challenges -- for social, environmental and economic benefits.

"These relationships we have on the border are very critical to our economic development," said Bureau of Reclamation Commissioner Michael Connor, whose agency manages dams that control and divert the Rio Grande and the Colorado River, which are shared by the two countries. Development cannot occur without a reliable water supply to support it, officials emphasized throughout the two-day conference, held in Juarez and El Paso, Texas.

"This economy has grown up in a very arid environment. And our challenges are going to grow, and they're going to get more significant" as temperatures rise and stream flows fall due to climate change, Connor added. "The time is now."

Felipe Arreguin Cortes, a technical director with CONAGUA, the national water commission in Mexico, echoed Connor's concerns about climate change.

"We are facing an unfavorable scenario because of climate change," he said. "On the Rio Grande, there's increased competition for water, and we have to avoid all the binational conflict. And we need to be very careful about the aquifers to avoid any problems."

But there are key differences between the two countries that make it difficult for officials and scientists in the United States and Mexico to work together.

In Mexico, for example, all water is owned by the federal government, including surface water and groundwater, but in the United States, surface water and groundwater are managed separately by state and federal interests, noted dos Santos, who coordinates the Transboundary Aquifer Assessment Program, which evaluates and maps shared aquifers along the border.

Data gap

Key differences in scientific methodology on either side of the border also pose problems for getting a handle on water resources in the region.

The United States and Mexico use different soil classification systems, creating a significant wrinkle in an effort by the University of Arizona, the U.S. Geological Survey, the University of Sonora in Mexico and other participants to craft binational reports assessing shared aquifers on the border.

"We recognize there are some things we won't be able to do," dos Santos said during a summit presentation on the Transboundary Aquifer Assessment Program. "There's an effort to integrate as much as we can."

Along the mostly arid 2,000-mile U.S.-Mexico border, home to about 13 million people, demand for water is putting increasing pressure on the region's already limited water resources. Photo by April Reese.

Eventually, program administrators hope to develop three-dimensional models for the aquifers, which are "essential" to future planning efforts, he added. But money's a problem.

"The funding will expire in March of 2013," dos Santos said. "So unless there are other resources identified from the U.S. government, this program will cease, and that means we won't be able to develop the binational model we're hoping to see."

The United States and Mexico should work together to identify the resources needed to continue the work, he said.

Without understanding how much groundwater is available, who has what and how it's going to be managed, the two countries could once again find themselves at loggerheads, as they once were over shared river resources, he added.

"This is a very important issue. It can cause widespread suffering and pain and economic and physical consequences," dos Santos said. "This can lead to tensions and conflict. These are issues that have long-term implications, and it's much better to act proactively."