Large scale projects and tunnels another innovation

large-scale projects and tunnels.
Another innovation that allowed Roman aqueducts to cross valleys was the inverted siphon. These
were made of clay or multiple lead pipes, reinforced with stone blocks and with the power of gravity
and pressure. As the water ran down the valley, the momentum gained could drive the water up the
opposite side. The quick changes of pressure and sometimes volume, depending on the lengths of the
drops and rises, meant that an airshaft was necessary for equalisation when the water resumed its
normal downwards flow.

IELTS 5 Practice Tests, Academic Set 2 TEST 6 READING
Page 139
One of the most significant aqueducts built by the Romans ran for 106 kilometres from modern-day
Jordan to barren Palestine. Qanat Firaun, ‘The Canal of the Pharaohs,’ is what the locals call the
weathered old pipeline, but research recently carried out has discovered that it was Roman work.
Starting in a since dried out swamp in Jordan, it carried water to the city of Gadara, a city that has also
disappeared. The aqueduct was covered the whole way, which had several benefits. Firstly, this
protected the water from animals, birds and dust. Secondly, this is a very hot area in summer and the
cover prevented evaporation and loss of water. Finally, the cover prevented light from reaching the
water, which stopped the growth of algae that would have spoiled the water’s freshness.
Rome itself was generously served by a water system including eleven different aqueducts. When
water reached Rome, it flowed into enormous cisterns maintained on the highest ground. These large
reservoirs held the water supply for the city and were connected to a vast network of lead pipes. The
water system was as politically motivated as any other massive public works project. Providing
additional sources of incoming flow, feeding the baths or simply providing water access to more of the
populace could grant gr eat prestige. At the height of the ancient city’s population of approximately
1,000,000 inhabitants, the water system was capable of delivering up to one cubic meter of water per
person per day in the city, more than what is commonly available in most cities today.
Maintenance of the water system was a continuous task, and the Romans assigned a ‘Curator
Aquarum’ to oversee this undertaking. Paid labourers, slaves and the military all had parts in building
parts of the water system. The Curator Aquarum maintained the aqueducts of Rome, while similar
curators oversaw those in the provinces. The army, however, when building new colonies or forts, were
responsible for providing their own water supply. Just as they were the great road builders of the
Empire, the Romans also revolutionised societies with their aqueduct construction in outlying areas.