ROMAN AQUEDUCTS MARVELS OF ENGINEERING

F ALL the feats of ancient engineer- , dedicated in 19 B.C.E. The O ing, Roman aqueducts are among builder of this aqueduct, Marcus Agrippa, the most remarkable. “With such an array a close friend of Caesar , poured of indispensable structures carrying so much of his vast fortune into overhauling many waters, compare, if you will, the idle and extending ’s water-supply sys- Pyramids or the useless, though famous, tem. works of the Greeks!” wrote Sextus Julius Baths also became social venues, larg- (35–c. 103 C.E.), Roman gover- er ones even having gardens and librar- nor and water commissioner. ies. After leaving the baths, aqueduct wa- ter, which could not be shut off, flowed Why the Need for Aqueducts? into the sewers, constantly flushing them Ancient cities were usually built near of refuse, including waste from the la- an abundant water supply, and Rome trines attached to the baths. was no exception. Originally, the Tiber Riv- er and nearby springs and wells provid- Construction and Maintenance ed sufficient water. From the fourth centu- When you hear the words “Roman ry B.C.E. on, however, Rome grew rapidly, aqueduct,” do you think of lofty arches as did its need for water. running to distant horizons? In fact, Since few people had running water in arches formed less than 20 percent of their homes, the Romans built hundreds those conduits, the larger portion of of private and public baths. The first pub- which lay underground. This more eco- lic bath in the city of Rome was fed by the nomical design not only protected aque- ducts against erosion but also minimized  The Romans were not the first to build water con- their impact on fields and neighborhoods. duits. Other ancient nations, such as Assyria, Egypt, India, and Persia, preceded them in this. For example, the , completed —a % in France

in 140 B.C.E., was about 57 miles (92 km) Rome’s Urban Aqueducts long but comprised just 7 miles or so By the early third century C.E., 11 major (11 km) of arches. aqueducts served the city of Rome. The Before building an aqueduct, engineers first, the , built in 312 B.C.E. assessed the quality of a potential water and just over ten miles (16 km) long, ran source by examining the clarity, rate of almost entirely underground. Still pre- flow, and taste of the water. They also served in part is the , which took note of the physical condition of the was some 43 miles (69 km) long with locals who drank it. Once a site was ap- about 6 miles (10 km) of arches, a num- proved, surveyors calculated the right ber of which stood 90 feet (27 m) high! path and gradient for the conduit, as well How much water did the city’s aque- as its channel size and length. Slaves evi- ducts carry? A lot! The Aqua Marcia, men- dently provided manpower. Aqueducts tioned earlier, daily channeled about could take years to complete, making 6.7 million cubic feet (190,000 cu m) of them costly—especially if arches were water into Rome. Once the water reached needed. urban areas—gravity being the driving Moreover, aqueducts had to be main- force—it flowed into distribution tanks and tained and protected. To care for them, then into branches, which channeled the the city of Rome at one time employed water to other distribution tanks or to lo- about 700 people. Provisions for mainte- cations for water use. Some estimate that nance were also incorporated into the de- Rome’s water distribution system grew to sign. For instance, underground sections the point that it could have daily supplied of the aqueducts were made accessible more than 265 gallons (1,000 L) of water by means of manholes and shafts. When for each inhabitant. major repairs were needed, engineers As the grew, “the aq- could temporarily divert the water away ueducts went wherever Rome went,” says from a damaged section. the book Roman Aqueducts & Water Sup- ply. Travelers in Asia Minor, France, Spain, and North Africa can still gaze in awe at these ancient marvels of engineering. ˛

Inspection shafts Intake

Covered channel Water Settling tank source Distribution tank City

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