This is the gigantic hole that swallows Lake Berryessa

A massive 22-meter diameter hole appears in the Monticello Dam of Lake Berryessa, in California's Napa Valley. Up close, it may seem like a supernatural phenomenon of unknown origin or give the impression that a monster could emerge from within at any moment, but nothing could be further from the truth. It is simply a system to drain water from the reservoir when it exceeds 134 meters. Instead of opting for a drainage system based on gates that open to evacuate water, like most dams, they chose to do something different. The optical effect it produces is, to say the least, shocking.

This whirlpool is known as the 'Glory Hole', and it is only visible when the water evacuation system is active. The rest of the time it remains deactivated, and the impounded water stays calm. In principle, it should only need to operate once every long while, as in California rainfall is scarce and the water in the reservoir rarely exceeds 134 meters; however, in recent years, it has been activated more times than one might expect.

In 2006, 2017, and 2019, the 'Glory Hole' was observed consuming water from the reservoir to expel it. This, according to experts from Science Alert, could be due to climate change: 'In the 1950s, when engineers built it, they thought it would only be used once every 50 years in extreme scenarios. However, since the turn of the century, the whirlpool has opened three times already. Another reminder that the climate of our world is changing.'

Although this drainage system is not destructive and a person could easily swim against the current to escape it, the reservoir is cordoned off. Any recreational activities such as swimming, boating, or similar are completely prohibited. After all, we are talking about a gigantic hole that swallows 1.3 million liters of water per second.

The purpose of this safety cordon is also to prevent a possible tragedy. When the system was activated in 2017, hundreds of people gathered around the dam to marvel at how this gigantic hole functioned, according to local media. While nothing happened, authorities preferred to be cautious and ensure that no one could get too close to prevent the potential temptation that some might have to jump into the water.

In fact, there was a similar incident back in 1997. That year, a woman entered the reservoir and swam toward the hole while it was operational. A current pulled her in, and she clung to the edge of the structure for about 20 minutes to avoid being swallowed, but it was not enough. Rescue teams found her lifeless body hours later. In light of this unfortunate accident, and seeing the mass of curious onlookers that gathered in 2017 around the dam, the area was cordoned off. In an era where many put themselves at risk for attention on social media, the responsible parties have preferred to prevent rather than cure.