The World’s Largest Drain

Thursday, 24th April 2008 by

Here in Lake Berryessa, California, we find the largest drain hole in the world, affectionally known locally as The Glory Hole.

Narrowing from 22 metres diameter to 8.5 metres at its thinnest point, this absolutely enormous funnel is technically the largest “morning glory spillway” in the world – an uncontrolled outlet which, should the water level rise sufficiently high, allows up to 1370 m³ per second (48,400 cubic feet) of water to bypass the Monticello Dam. Check out this photo of the spillway in full flow.

The spillway’s horizontal exit is on the southern side of the dam, and this ground level shot demonstrates why this is a popular spot for local skateboarders and bikers during the drier months!

Read more about spillways, the Monticello Dam and Lake Berryessa at Wikipedia, and has some fascinating photos of the spillway during construction in the 1950s.

Thanks to Mark and fogonazos.