Lake Berryessa Glory Hole

Lake Berryessa Glory Hole; California
Lake Berryessa is the largest lake in the Napa County, California. It is very important because it is not only a tourist attraction but more so, it generates hydroelectricity to the North bay region of the San Francisco Bay.
What makes it interesting and amazing is the bell-mouth spillway located at the south-eastern side of the lake. This "Glory Hole" is the largest of its kind with a diameter of 72 feet. The hole has a vertical drop of 200 feet and shrinks down to 28 feet. Once the water level reaches the maximum level, the spillway becomes submerged and it swallows excess water at an unbelievable rate of 48,800 cubic feet per second. The excess water goes into a concrete pipe 700 feet away from the lake at the other side of the dam.
People are not permitted to go near the hole especially when the water level is high for obvious reasons. There are buoys placed across the lake to prevent swimmers and boaters in going beyond the marked line.