For the first time since 2019, the massive “glory hole” at Lake Berryessa in Napa County is once again visible, as heavy winter rains have pushed the lake’s water level above 440 feet. This rare phenomenon, known as spillover, is the result of the Morning Glory spillway—an enormous, 72-foot-wide circular drain—that allows excess water to flow 200 feet downward into Putah Creek, preventing the lake from flooding.

The spectacle occurs when the lake’s water level rises high enough, typically only during the wettest periods. This year, the heavy rains throughout winter have led to spillover, bringing the glory hole back into public view. The event has become a major attraction, drawing crowds of curious onlookers eager to witness the rare sight.

What Is the Morning Glory Spillway?

The Morning Glory spillway, also known locally as the “glory hole,” is an enormous concrete drain built to manage overflow from Lake Berryessa. When the lake’s water level exceeds the spillway threshold, which is 440 feet, water flows into the massive drain and cascades into Putah Creek below, preventing the lake from spilling over its banks. This process, called spillover, makes the lake appear to have a giant hole in its center, with water rushing into the mouth of the drain. The effect is similar to a giant flower, earning the official name of “Morning Glory” due to its resemblance to the flower’s shape.

A unique phenomenon, dubbed the ‘Glory Hole’ spillway, was activated at Lake Berryessa in California after a storm swept through the area. pic.twitter.com/6jzVmOd3PT

— USA TODAY (@USATODAY) February 14, 2025

While the structure is intended to manage water flow, it has also captured the fascination of locals and visitors alike. The phenomenon has been a source of local lore since the 1960s when residents first began referring to it as the “glory hole.” Seeing it in action, however, is rare. Lake Berryessa’s water level typically stays below the spillway threshold, and the enormous drain remains largely out of sight.

A Rare Event Draws Tourists

As of February 4, 2025, after torrential rains from an atmospheric river storm caused the lake’s water level to surpass the spillway’s 440-foot mark, the glory hole began to spill over. This event has lasted for more than 40 days, a rarity in the history of the spillway. As of the most recent reports, the water level at Lake Berryessa remained six inches above the spillway level. However, local experts anticipate that it will likely fall below the threshold in the coming days, possibly ending the spillover event.

Chris Lee, general manager of the Solano County Water Agency, told the San Francisco Chronicle that while the spillover could end soon, there is still a possibility of further rainfall causing the water level to rise again. “If we get significant runoff, we could see it last beyond next week,” Lee said. This unpredictability has only added to the excitement for those eager to witness the event.

The spillover also serves as a reminder of the region’s complex water management system. Lake Berryessa provides crucial irrigation for local farms and drinking water for approximately 500,000 people. When the glory hole activates, the resulting flow is carefully managed to protect the lake’s surrounding infrastructure and ensure safe water levels.

Design and Safety Features of the Glory Hole

Constructed between 1953 and 1957, the glory hole is part of the Monticello Dam, which impounds Putah Creek to create Lake Berryessa. The design of the spillway was carefully crafted to create a smooth, laminar flow of water, which helps prevent the formation of a dangerous whirlpool. Without this design, the force of the water could potentially cause boats or even swimmers to be sucked into the drain.

Though the spillway is designed to prevent such accidents, the danger is real. The most notable incident occurred in 1997, when a woman tragically drowned after being pulled into the drain. Authorities said the woman had been swimming near the spillway when she disappeared, and her body was later found after she had struggled to cling to the hole’s edge. This remains the only known fatality associated with the Morning Glory spillway.

To keep the public safe, authorities have placed a line of buoys around the spillway to prevent boaters and swimmers from getting too close. The area has also become a popular spot for tourists, who gather at a designated viewing area along Highway 128 to watch the spectacle from a safe distance.

Spillover Events Are Rare But Memorable

Spillover events are infrequent but can last for extended periods when the lake’s water level stays high. The last prolonged spillover occurred in 2017 when water began pouring into the glory hole in February and continued through May. These events tend to attract tourists from across the state, especially during the height of spillover when the lake is at its most dramatic.

As the spillover continues, many are taking advantage of the opportunity to see this rare phenomenon in person. Chris Lee described the sight as “definitely worth seeing,” noting the thrill of witnessing the power of nature as the lake’s water cascades into the massive concrete drain.

While the glory hole may not be a common sight, the spillover serves as an important reminder of the role that water infrastructure plays in managing the region’s water resources. The Morning Glory spillway has stood the test of time, offering both a safety mechanism for flood prevention and a source of fascination for those fortunate enough to witness its rare display.

What’s Next for the Glory Hole?

As the atmospheric conditions in the region begin to stabilize, the spillover event at Lake Berryessa is expected to subside. However, experts will continue to monitor the water levels closely, and there may be more opportunities to witness the glory hole in action later this year. For now, locals and tourists alike are taking advantage of the rare chance to see one of California’s most fascinating natural attractions.

For more information about Lake Berryessa and the Morning Glory spillway, as well as updates on water levels and spillover events, visitors can consult the Solano County Water Agency or stay tuned to local weather reports.