They were extensively used throughout the Middle East and Northern Africa (McDonald, 1998). In the city of Aleppo, Syria, drinking water still comes from a qanaat, that brings water from a spring over seven miles away (Grolier, 1993).
One of the earliest known aqueducts built above ground was the aqueduct of Jerwan. King Sennacherib of Assyria started construction on this aqueduct in 691 BC. This huge aqueduct carried water from the Greater Zab River to the king's fields and garden in Nineveh, which was over fifty miles away. A 30 foot high arched bridge was needed to support this aqueduct as it passed over a valley (Grolier, 1993).
Another amazing aqueduct was built on the island of Samos in around 530 BC. Designed by the Greek engineer Eupalinus, the Samos structure ran mostly underground. The tunnel was approximately 1 mile long and almost eight feet in diameter. The water flowed through clay pipes that were laid inside the tunnel (Grolier, 1993).
"The most famous aqueduct builders of ancient times were the Romans" (McDonald, 1998). Roman engineers built the main part of their aqueduct system at or below ground level. The water was carried through free flowing conduits. When the aque
One of the earliest known aqueducts built above ground was the aqueduct of Jerwan. King Sennacherib of Assyria started construction on this aqueduct in 691 BC. This huge aqueduct carried water from the Greater Zab River to the king's fields and garden in Nineveh, which was over fifty miles away. A 30 foot high arched bridge was needed to support this aqueduct as it passed over a valley (Grolier, 1993).
In the United States, aqueduct systems supply water to Boston, Baltimore, Washington DC, Saint Louis, New York, and Los Angeles, among other cities (Funk Wagnalls, 1983). "The water supply system for New York City is among the most elaborate in the world" (McDonald, 1998). This system is almost 200 miles long, and most of it is located underground. "The main aqueducts under New York are between 200 and 600 feet below sea level" (Funk Wagnalls, 1983). Most of the water in New York comes from watersheds to the north. The water is stored there in reservoirs and natural lakes. The Croton, Catskill, and Delaware aqueducts carry the water to the city (McDonald, 1998). The Delaware System, which caries 800 million gallons of water a day from the Catskill Mountains to New York, is approximately 85 miles long. Completed in 1965, it is the longest continuous tunnel in the world (Funk Wagnalls, 1983).
Aqueducts were built in many areas of the Roman empire. "Remains of these aqueducts still exist. A few of them, such as the one at Segovia, Spain, have remained in use" (McDonald, 1998). Shown in Figure 1, is the Roman aqueduct in Segovia, Spain. At a height of 128 feet, the aqueduct was constructed from granite. It is a fine example of dry masonry. Figure 2 shows one of the most remarkable old roman aqueducts, the Pont du Gard near Nimes, France. Built in 19 BC, it is composed of three tiers of semicircular arches, bringing its height to 160 feet above ground (McDonald, 1998). It was estimated that the 11 roman aqueducts would provide over 38 million gallons of water a day (Funk Wagnalls, 1983).
d rocks (Grolier, 1993). They were
20
1391 
6 
6 
)
