Today, we use water to change the face of the
earth. The University of Houston's College of
Engineering presents this series about the machines
that make our civilization run, and the people
whose ingenuity created them.
Technology has always
seesawed between two poles -- carving the world to
fit our wants one moment, and yielding to the
natural order of things the next. That
contradiction has always been clearest when we
manage earth's water. No ancient technology touched
people's lives, or the face of the earth, as
strongly as irrigation did. The great Egyptian
civilization could be formed only after the arid
Nile Valley had been watered.
Our early Southwestern settlers just as surely had
to bring water to the land before they could turn
from herdsmen-cowboys into settled farmers. But a
great change had taken place by then: First,
medieval millwrights coupled water-management with
power production. Then, during the 1820s and '30s,
French and American engineers transformed the
medieval water wheel into the modern water turbine.
By the mid 19th century, water control had been
tied to power generating systems of heroic size.
So the Colorado river caught the minds of engineers
as it flowed 1800 miles through the Western deserts
-- 200,000 cubic feet of water per second. The
Colorado was first explored in 1872. In 1901, a
large part of it was diverted into 100,000 acres of
the Imperial Valley in Southern California. The
desert bloomed until 1905. Then a flash flood
inundated the sub-sea-level Valley and wiped out
whole towns. It took two years to regain control of
the river. By now it was clear that a huge dam and
power plant should be placed across the Colorado
river.
Then Congress entered the picture. It debated the
project through seven presidents, starting with
Teddy Roosevelt. Finally Herbert Hoover, one of the
great engineers of this century, took office. He
immediately gave the green light to a civil
engineer named Elwood Mead. Mead began what was at
first called Boulder Dam. It was the world's
largest concrete structure. Mead took it almost to
its completion in 1935. Then he died just months
before it opened.
The dam was soon renamed Hoover Dam. Its reservoir,
reaching 140 miles back through Nevada and Arizona,
is named Lake Mead. The dam couples iron control of
irrigation and flooding with 1434 megawatts of
power output. Bigger dams have been built since
then; but Hoover Dam lit the way to a whole network
of huge hydroelectric dams throughout America.
It also represents engineering at its best. In it,
the imposition of our will upon the land is coupled
with a powerful sense of stewardship toward the
earth.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
