The nation's capital is not exactly a beach town. But the cherry-tree-lined Tidal Basin, fed by the Potomac River, laps at the steps of the Jefferson Memorial. And, especially since Superstorm Sandy, officials in Washington have a clear idea of what would happen in a worst-case storm scenario.
"The water would go across the World War II memorial, come up 17th Street," says Tony Vidal of the U.S. Army Corps of Engineers. "And there are actually three spots where the water would come up where we don't have ... a closure structure right now."