Ancient Rome (753 b.C. – 1453 a.D.)
Aqueducts gather water from natural springs and moved water through gravity alone, being constructed along a slight downward gradient within conduits of stone, brick or concrete. Spring-water was fed into a stone or concrete springhouse from uphill, then entered the aqueduct conduit. Most were buried beneath the ground, and followed its contours; obstructing peaks were circumvented or, less often, tunnelled through. Where valleys or lowlands intervened, the conduit was carried on bridgework, or its contents fed into high-pressure lead, ceramic or stone pipes and siphoned across. Most aqueduct systems included sedimentation tanks, sluices and distribution tanks to regulate the supply at need.
They were built in many different materials, like stone and bricks, coated with Opus signinum (a special building material made of tiles broken up into very small pieces, mixed with mortar, and then beaten down).
Metal pipes, made of lead or bronze, were very expensive. Furthermore, lead was not suitable for long pipes and for this reason it was mainly used in the city. Steel was not available and cast iron was hard to work.