"SANTA URSULA, Mexico — People in the hamlet of Santa Ursula began to worry when the logging started. In a few short weeks, more than a mile of densely forested riverbank was stripped from the Arroyo Sal to make way for heavy dredging equipment.
Work was just beginning in late 2010 on an ambitious, three-year, $30 million project to build a 15-megawatt hydroelectric plant directly adjacent to the Cerro de Oro dam, with support from a U.S. government agency in Washington.
Next came dynamite explosions as crews blasted through rock to create a tunnel designed to feed power-generating turbines. In Santa Ursula, some 1.5 miles away, the ground shook and cracks formed in homes, some residents say. Finally murky gray water began flowing from the taps, leading locals to fear the worst: contamination in the gurgling mountain spring that provides drinking water for nearly 2,000 people and feeds the arroyo."