Marc Reisner said this quote
“ By erecting thirty thousand dams of significant size across the American West, they dewatered countless rivers, wiped out millions of acres of riparian habitat, shut off many thousands of river miles of salmon habitat, silted over spawning beds, poisoned return flows with agricultural chemicals, set the plague of livestock loose on the arid land--in a nutshell they made it close to impossible for numerous native species to survive. ”