Hoover dam

Didn't seem that big until you were on it, the lake behind it's running at 28% crazy, the crazyer bits is las Vegas and Henderson city are still growing... Huge city's with limited water, they were saying they may have to build desalination plants from the Pacific and pump water in... Geeesh 

Think that's a 2035 or 2050 problem

Another fun fact, sounds like the 9/11 guys originally were looking at renting a sub?? And attempting to blow up the dam?? Wtf. And that's why the overpass bridge was built..