What structure is designed to carry water over long distances?

The structure specifically designed to carry water over long distances is an aqueduct. Historically, aqueducts were engineered as channels or bridges that transport water from a source, such as a river or lake, to populated areas or agricultural fields, where it is needed for consumption, irrigation, or other uses. The construction of aqueducts often involved sophisticated techniques and engineering, including the use of arches and gravity flow to ensure that water could be moved efficiently across various terrains.

While pipelines also transport water, they are generally considered a more modern solution involving sealed tubes, often used for shorter distances. Reservoirs are storage structures that hold water for future use but do not themselves transport water. Waterways, such as rivers and canals, may facilitate the movement of water but are not specifically designed for that purpose in the same way aqueducts are. Thus, aqueducts represent a classic and deliberate method for long-distance water transportation.