Percy Deal, a member of the Navajo Nation, is looking up at a pale stripe of sandstone that stands out against the rim of Black Mesa in northeastern Arizona. Juniper trees speckle the steep cliffsides facing the site of a proposed hydropower project. … The hydropower company Nature and People First applied for preliminary permits from the Federal Energy Regulatory Commission (FERC) last year to investigate the possibility of building three pumped water storage projects on and below Black Mesa to generate electricity for nearby cities like Phoenix and Tucson. Deal and other Black Mesa residents are worried that the project could do damage to land and water that has ecological and cultural significance to both the Navajo and Hopi tribes. … They’re concerned about potential overuse of groundwater underneath the Black Mesa region, which is still reeling from the environmental consequences of decades of extractive coal strip mining.