Lake Berryessa
| Lake Berryessa | |||||
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| Coordinates | 38 ° 34'15 " N , 122 ° 14'7" W | ||||
| Data on the structure | |||||
| Lock type: | Reservoir | ||||
| Data on the reservoir | |||||
| Water surface | 84 km² | ||||
| Reservoir length | 24.9 km | ||||
| Reservoir width | 4.8 km | ||||
| Storage space | 1.976 km³ | ||||
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The Lake Berryessa is a dam in Napa County in the US -Bundesstaat California . The lake was named after the first European settlers in the Berryessa Valley, José Jesús and Sexto Sisto Berrelleza, who settled in Rancho Las Putas in 1843 . The reservoir is dammed up by the Monticello dam .
It has a catchment area of 1490 km² and an area of 84 km², which is spread over a length of 24.9 kilometers and a width of 4.8 kilometers. The deepest part of the lake is about 84 meters.
"Morning Glory Spillway"
The overflow funnel , which is located on the water side of the dam and is considered to be the world's largest structure of this type, achieved great fame . It is known as the Morning Glory Spillway , Glory Hole or Bottomless Pit and serves as a flood relief system : Once the dam target has been reached, it prevents the dam wall from subjecting the dam to excessive water pressure if the lake level rises further. It also prevents the water from flowing over the dam. Possible associated damage to the dam - or, in the worst case, total failure - are thus avoided.
Its largest diameter on the water surface is 22 meters and tapers to 8.5 meters. The shaft falls about 60 meters vertically, before it runs another 155 meters to the foot of the dam, where it emerges on the air side and flows into a stilling basin . The huge funnel is able to hold 1,370 cubic meters of water per second. This creates a suction that even the most capable and strongest swimmers cannot swim against.
The overflow system is well known in the skater scene; if no water shoots through the huge pipe (when the water level in the reservoir is low), the skaters do not use the overflow funnel, but the horizontal outlet opening of the overflow system and the not too steep parts of the pipe in between as a half pipe .
In 1997, the then 41-year-old Emily Schwalek from Davis swam too close to the Glory Hole . According to eyewitnesses, she managed to hold on to the edge of the funnel for about 20 minutes before she was torn down.
Web links
- (archive.org) The Monticello Dam Controversy and “Lake” Berryessa
- Lake Berryessa in the United States Geological Survey's Geographic Names Information System