See the context of this sign.

Working Water

Lee Vining Creek
and Southern California Edison

The Power of Mountain Waters

Forest Service land has many uses. An example you see hiere is the
production of clean, renewable hydroelectric power. This small dam
collects Lee Vining Creek water in Ellery Lake. The dam is part of
Southern California Edison's (SCE) Lee Vining system which
began operation in 1924. Each year this system can produce 29
million kilowatt hours of electricity, enough energy to meet the
needs of a city of 20,000 people.

Water from Ellery Lake descends a 3,740 foot long penstock
into the power plant on the valley floor, dropping 1,659 feet
in just over a mile! It arrives at the power plant with a
pressure of 720 lbs per square inch, enough to drive
a 12,500 Kilovolt-ampere (KVa) generator.
After driving the generator, the water
returns to its creekbed and
continues its journey toward
Mono Lake.

Don't miss the rest of our virtual tour of Lee Vining Canyon in 614 images.