Air Date: Week of September 27, 1996

Facts about... the Hoover Dam.

Transcript

CURWOOD: Sixty-five years ago engineers working along the Colorado River in Nevada began constructing what was called the Eighth Wonder of the World. When it was completed 5 years later, Hoover Dam stood 736 feet high and nearly 1,200 feet long, the largest dam in the world at the time. Behind the dam now sits Lake Mead; it's the largest reservoir in the US today. But it's threatening to become the nation's largest mudhole. That's because silt from the Colorado River is getting trapped behind the dam and building up in Lake Mead. It's a common phenomenon, and typically large dams have a lifespan of about 100 years before their impoundments fill with silt. It's unclear what the life span of the Hoover Dam will be, but when its turbines shut down it will certainly be missed from the nation's power grid. Last year Hoover Dam produced nearly 4 billion kilowatt hours of electricity. And for this week, that's the Living on Earth Almanac.