Technology
The ancient Romans also had a complex system of aqueducts, which were used to transport water across long distances. The first Roman aqueduct was built in 312 BCE. The eleventh and final ancient Roman aqueduct was built in 226 CE. Put together, the Roman aqueducts extended over 450 kilometers, but less than seventy kilometers of this was above ground and supported by arches.
District of Columbia Water and Sewer Authority
In 1852, Congress commissioned the construction of an aqueduct system to provide a reliable supply of drinking water to the city from the Potomac River. The US Army Corps of Engineers designed and built the Washington Aqueduct, which began full operation in 1864. Filtration plants were added to the system in the 20th century.