Recently in California, Lake Berryessa’s water levels have surged due to consecutive storms, triggering a rare giant funnel-shaped whirlpool that has attracted a large number of visitors. Although this phenomenon is a sight to see, local officials are reminding visitors to prioritize their safety.
The phenomenon originates from the “Morning Glory Spillway,” a funnel-shaped drainage facility designed to prevent the lake from overflowing. This week’s flooding is the first time it has occurred since 2019. Lake Berryessa is located 70 miles northeast of San Francisco and was formed in 1957 during the construction of the Monticello Dam.
Due to its location in a narrow canyon, traditional spillways could not be built at Lake Berryessa. Therefore, the unique design of the Morning Glory Spillway, resembling an overflow hole in a bathtub, was implemented to discharge water into Putah Creek when the water level becomes too high. Such spillways are rare in the United States, with similar facilities found only near Shasta in the Whiskeytown National Recreation Area.
According to BBC reports, this is the first time in six years that the flood mechanism has been activated. Local officials have stated that this sight has become a highlight following the heavy rains in California, attracting a large number of tourists.
Lake Berryessa’s Morning Glory Spillway has only been activated in 2006, 2017, and 2019. After the 2022 California drought, heavy rains and snowfall in 2023 caused the water levels to rise, resulting in this year’s flooding.
The spillway is expected to operate until the end of this week, possibly extending for one to two more weeks. However, local officials are warning swimmers and boaters to stay away from the spillway to avoid being swept away by the water flow. In 1997, a woman tragically fell hundreds of feet to her death, and in 2019, a cormorant was sucked into the water flow, a moment captured on camera.
Brionna Ruff, a spokesperson for the Bureau of Reclamation, mentioned to SFGate.com that it was highly unlikely for the bird to survive being pulled into the whirlpool.