Lake Berryessa, a reservoir about two hours north of San Francisco, is formed by the Monticello Dam and features an open bell-mouth spillway, 72 feet wide with a vertical drop more than 200 feet deep.

The mesmerizing vortex is a beautiful example of a “bell-mouth spillway,” a unique form of infrastructure that controls water overflow during particularly heavy rain periods by rerouting the ...

The spillway, built from timber in the 1880s, has never had an official name The bell-mouth design is also known as morning glory (after the flower) or glory hole The council is searching for a ...