Explore Glory Hole, a man-made 'monster' hole

From the outside, it looks like a monster black hole ready to suck up any object that comes close.

Glory Hole is a purpose-built spillway dam that re-regulates Lake Berryessa's water during the rainy season, avoiding excessive surges.

Lake Berryessa was built in 1953 and can hold up to 1,970km3 of water for the purpose of supplying water and hydroelectricity to the Northern Gulf. The rainy season of this area is often very large and lasts for many weeks of the year, with a very high risk of flooding. As a result, the highways around the area are often closed because of these torrential rains, thousands of people have to evacuate their homes due to the risk of flooding.

So, in 1957, the American Bureau of Reclamation built the Glory Hole.

When the amount of water in Lake Berryessa is low, the Glory Hole will appear in the middle of the lake and is completely harmless because everyone can see it, a strange concrete tower.

But when the water level is higher than the hole, the water will be sucked down the hole and moved into a narrower pipe, then poured into the Putah Creek area half a kilometer away. At that time, the scene of Glory Hole as shown in the photo appeared, the water rose and overflowed into the crater creating a giant vortex that seemed to be able to swallow everything.

Glory pit does not operate often, it has only been used 4 times since its completion in 1996, 2006, 2017 and 2019. Therefore, not everyone knows the existence of this drainage hole.

Although the Glory Hole crater is very large, it can absorb lake water at a speed of 1360 m3/s, but in fact the water flowing into the spillway is not too strong and not fast. To ensure everyone's safety, a pontoon line around the crater has been installed and will be regularly checked by someone.

Lake Beryessa is a popular boating area every summer. Many people including swimmers, water skiers, kayakers and canoeists gather here.

Due to an unfortunate accident that took the life of a man, all residents and visitors are prohibited from swimming near this drainage hole. However, as long as you don't get close to the deep water area, don't cross the buoy area around this crater, all the remaining places on the lake surface can check-in and swim comfortably.

Samuel Daniel

Update 11 July 2022