“Give a Dam About Climate Change,” declares a new sky-high message that reminds visitors en route to the Hoover Dam that eating just 1 pound of meat “Give a Dam About Climate Change,” declares a new sky-high message that reminds visitors en route to the Hoover Dam that eating just 1 pound of meat wastes 1,800 gallons of water. The can’t-miss PETA plea greets visitors to the iconic monument, who will learn that the dam generates enough hydroelectric power to serve 1.3 million people each year—but won’t hear another vital fact: that an estimated 55% of the freshwater supply in the U.S. goes to raising animals for food. Talk about waste water!