where do most cities get their water supply
Drinking water supply and sanitation in the United States The centralized drinking water supply infrastructure in the United States consists of dams and reservoirs, well fields, pumping stations, aqueducts for the transport of large quantities of water over long distances, water treatment plants, reservoirs in the distribution system (including water towers), and 1.8 million miles of distribution lines.[5]:14 Depending on the location and quality of the water source, all or some of these elements may be present in a particular water supply system. In addition to this infrastructure for centralized network distribution, 14.5% of Americans rely on their own water sources, usually wells.[11][12]
Roman aqueduct Springs were by far the most common sources for aqueduct water; for example, most of Rome's supply came from various springs in the Anio valley and its uplands. Spring-water was fed into a stone or concrete springhouse, then entered the aqueduct conduit. Scattered springs would require several branch conduits feeding into a main channel. Some systems drew water from open, purpose-built, dammed reservoirs, such as the two (still in use) that supplied the aqueduct at the provincial city of Emerita Augusta.[19]