When it rains in the eastern Sierra Madre, near Mexico’s border with the United States, the rainwater courses down through funnel-like ridges in the mountains and collects in an oasis of the vast Chihuahuan Desert known as Five Springs. There, in five lush municipalities of Coahuila state, pecan trees dominate the landscape, and farmers involved in the vigorous pecan trade with the United States describe water as their destiny. “We have pecans, wheat and sheep because of the abundant water here,” says Javier Valdés, a 57-year-old farmer from the area. “It is our life. We depend on it.” But Valdés is worried. Last February, Petróleos Mexicanos (Pemex), the state oil company, began extracting three million cubic feet of shale gas a day... [Log in to read more]