Lake Berryessa's 'Glory Hole' returns for the first time in years, drawing visitors

NAPA, Calif. - It’s a mesmerizing visual treat, and the last time it happened was six years ago. A circular drain at Lake Berryessa in Napa County, known as the Morning Glory Spillway, has been active, drawing spectators seeking to get a glimpse of the rare funneling whirlpool.

The backstory:

The reservoir is owned by the Bureau of Reclamation and provides water to Solano County. It was formed as a result of the Monticello Dam which was built to trap Putah Creek's waters. 

The spillway, also known as Glory Hole, usually juts above the water's surface, but it gets activated into full flow when the water level rises to exceed the full pool at 439.96 feet above sea level, according to the Bureau of Reclamation.

"As Lake Berryessa fills during a wet season, the Spillway moves water around Monticello Dam," explained the Bureau's Jennifer Onufer. 

What we know:

Glory Hole spilled in early February following an atmospheric river-driven storm that pummeled the Bay Area. 

The level peaked on Feb. 14 at 443 feet, according to monitoring conducted by the Solano County Water Agency. 

On Tuesday, the water surface measured at 441 feet. 

The last time Glory Hole was activated was back in February and March of 2019, Onufer noted.

What we don't know:

It's unclear how much longer the spillway will remain active. 

Solano County Water Agency said it's hard to predict at this point, especially with the warm spring weather in the forecast.  

"I would guess it should continue spilling for another 3-4 weeks even with no more storms coming through," said the water agency's Supervising Water Resources Engineer Jay Cuetara.

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Popular spectacle 

Word of the rare spectacle has circulated, making the area a popular spot in recent weeks.

Bureau of Reclamation officials cautioned visitors to be aware of the congestion in the area.

Motorists along State Route 128 were advised to be careful and be prepared for the increased, spillway-generated traffic caused by both those on foot and in their vehicles.

Warning for boaters

Onufer also had an extra warning for those seeking to get a glimpse by boat. 

In addition to keeping a very safe distance, boaters were reminded about Lake Berryessa’s protocols that have been in place aimed at preventing the spread of the invasive golden mussels. 

All boats that launch at Lake Berryessa are subject to inspection and required to participate in a quarantine seal program.

More information on the lake’s boat protocols can be found here.