Aqueduct (water supply)

In modern engineering, the term aqueduct is used for any system of pipes, ditches, canals, tunnels, and other structures used for this purpose.

Historically, agricultural societies have constructed aqueducts to irrigate crops and supply large cities with drinking water.

Although particularly associated with the Romans, aqueducts were devised much earlier in Greece, the Near East, Nile Valley, and Indian subcontinent, where people such as the Egyptians and Harappans built sophisticated irrigation systems.

In Oman from the Iron Age, in Salut, Bat, and other sites, a system of underground aqueducts called falaj or qanāts were constructed, a series of well-like vertical shafts, connected by gently sloping horizontal tunnels.

There are three types of falaj: These enabled large scale agriculture to flourish in a dry land environment.

In Persia, starting around 3000 years ago [5] a system of underground aqueducts called qanāts were constructed, a series of well-like vertical shafts, connected by gently sloping tunnels.

This technique: Throughout Petra, Jordan, the Nabataean engineers took advantage of every natural spring and every winter downpour to channel water where it was needed.

They constructed aqueducts and piping systems that allowed water to flow across mountains, through gorges and into the temples, homes, and gardens of Petra's citizens.

[1] Near the Peruvian town of Nazca, an ancient pre-Columbian system of aqueducts called puquios were built and are still in use today.

[6] The Guayabo National Monument of Costa Rica, a park covering the largest archaeological site in the country, contains a system of aqueducts.

Originally tracing part of its path over now-gone Lake Texcoco, only a fragment remains in Mexico City today.

[10] In China, the South–North Water Transfer Project aims to connect the Yangtze River basin to Beijing through three separate systems.

[12] A constructed functional rill is a small canal or aqueduct of stone, brick, concrete, or other lining material, usually rectilinear in cross section, for water transportation from a source such as a river, spring, reservoir, qanat, or aqueduct for domestic consumption or agricultural irrigation of crop land uses.

A version of this common in North Africa and Central Asia that has vertical wells at regular intervals is called a qanat.

Pipelines are useful for transporting water over long distances when it needs to move over hills, or where open channels are poor choices due to considerations of evaporation, freezing, pollution, or environmental impact.

In California, United States, three large aqueducts supply water over hundreds of miles to the Los Angeles area.