Skip to main content

Why Do We Need Aqueducts?


How much water do you think a city like New York needs every day? The answer is that one billion gallons of water can flow into the city per day! Where does it come from and how does it get there? It comes from lakes and reservoirs many miles away and reaches the city by means of an aqueduct system.

An aqueduct is a man-made channel to carry water from a lake or reservoir in the hills to a village or city. The channel may be a canal, a tunnel, a pipeline, or a combination of all three. It is often many miles long and several feet in width or diameter.

The part that is a canal is usually dug, then lined with concrete, stone, or brick to prevent the earth from washing into it. Where the side of the valley is steep or uneven, a tunnel is used. Sometimes a tunnel cuts through to another valley. Usually it is cut through solid rock. The tunnel is lined with concrete, stone, or brick.

A pipeline is used when the aqueduct must dip down to cross a valley, along the uneven side of the valley or where the water must be kept clean. Pipelines are made of steel, or steel-reinforced concrete.

An aqueduct slopes gradually down-hill so the water will flow by gravity, but not so fast that it washes out the lining of the canal or tunnel. The more gradual the slope, the slower the speed will be, and the larger the aqueduct must be to carry a given amount of water.

The idea of aqueducts is very old. The ancient peoples of Egypt, Babylonia, and Assyria dug canals which brought fresh water from distant places into public pools or fountains. The Greeks built the first aqueducts in Europe, but the Romans built the most wonderful aqueducts until modern times. By the third century A.D., Rome had eleven aqueducts (some more than 50 miles long) supplying the city with' water from the distant hills.

Scroll to Continue

Related Articles