Justin Davis, age 13, of Las Vegas, Nev., for his question:
WHEN WAS THE FIRST AQUEDUCT BUILT?
A man made channel used to transfer water from its source to a location far away where it will be used is called an aqueduct. We don't know exactly were or when the first one was built, but we do know it was back in ancient times before men kept records.
One of the first aqueducts was built in Jerusalem. A series of 15 inch holes were hand drilled through blocks of limestone, and then the blocks were put side by side. There were many leaks in the system, but it still effectively transferred water to where it could be used, eliminating the previous need to haul it slowly in large jugs.
A masonry conduit was built by the Greeks to take water to their cities. The Greeks also used tunnels to carry water. A tunnel measuring 4,200 feet in length was built near Athens more than 2,500 years ago.
Most of the early aqueducts were built of stone, brick or a mixture of limestone and volcanic dust called pozzuolana.
A very effective system of aqueducts was built for the city of Rome in the olden days. By A.D. 97 there were nine aqueducts which daily brought in about 85 million gallons of water from mountain springs.
Rome's first aqueduct had been a 10 mile underground channel called Aqua Appia that was built about 300 B.C. during the time of Appius Claudius Caecus, for whom the Appian Way is named. The first Roman aqueduct to carry water above ground was built in 144 B.C. by Marcius. A bridged section was 10 miles long.
In the United States today many cities receive their water through systems of aqueducts. Among the major cities using aqueduct water are Los Angeles, San Diego, San Francisco, New York City, Washington, D.C., Denver, Tulsa, Baltimore, Boston and St. Louis. New York's system is more than 200 miles long. The California aqueduct system is the most extensive in the world. Winnipeg in Canada also has a major aqueduct.
California's aqueduct system is very complex. One section brings water from Parker Dam on the Colorado River 242 miles over the San Bernardino mountains. It has a capacity of more than one billion gallons of water daily.
The California aqueduct is the state's major water system. It carries water from the northern mountains to the southern part of the state in a network that runs a distance of more than 600 miles.
In addition to other projects, Los Angeles and other cities in the south use a separate supply of water that originates on the Owens River in the Sierra Nevadas. This system is about 340 miles long and it delivers almost 2 billion gallons of water each day.
Among the world's outstanding aqueduct systems is the one that carries water to Rio de Janeiro in Brazil. Another noted one is Apulian Aqueduct in southern Italy.