Množina: aqueducts

ETYM French aqueduc, Old Fren. aqueduct (Cotgr.), from Latin aquaeductus; aquae, gen. of aqua water + ductus a leading, ducere to lead. Related to Aqua, Duke.
Channel carrying water, especially in shape of bridge.
Any artificial channel or conduit for water, often an elevated structure of stone, wood, or iron built for conducting water across a valley. The Greeks built a tunnel 1,280 m/4,200 ft long near Athens, 2,500 years ago. Many Roman aqueducts are still standing, for example the one at Nîmes in S France, built about AD 18 (which is 48 m/160 ft high).
The largest Roman aqueduct is that at Carthage in Tunisia, which is 141 km/87 mi long and was built during the reign of Publius Aelius Hadrianus between AD 117 and 138. A recent aqueduct is the California State Water Project taking water from Lake Oroville in the north, through two power plants and across the Tehachapi mountains, more than 177 km/110 mi to S California.
Resembles a bridge but carries water over a valley.