The spillway at Lake Berryessa in California's Napa Valley works like a sink or tub overflow drain. It just automatically drains when the water level in the reservoir behind the Monticello Dam gets to a certain height. The locals call the round, accessible spillway the Glory Hole. Last week, after torrential rains, the water level got high enough to reach the Glory Hole for the first time in ten years -and this time, we have drones to record it. Bonus: AC/DC.
The concrete funnel is 72 feet wide, and goes to work when the water reaches 440 feet above sea level. In the video, it is draining at about two million gallons a minute. In case you are wondering, here's what the Glory Hole looks like when the water level is low. -via Digg