How were deep wells used in the ancient Indus River basin and ancient China?

In the context of ancient water supply systems, the development of deeper wells was a significant technological advancement driven by the needs of growing urban populations.1

• Indus River Basin: As early as 2500 BCE, city dwellers in the Indus River basin constructed brick-lined wells to access groundwater. These structures represented an evolution from the earliest, simpler shallow wells.1
• Ancient China: Ancient Chinese engineers achieved remarkable depths in well construction, with records indicating the use of wells reaching nearly 500 meters (more than 1,600 feet) deep. Furthermore, in western China, deep shafts were cut into rock specifically to recover brine for the salt industry, demonstrating advanced excavation capabilities.12

These innovations in well-digging were part of a broader history of water management in the ancient world, which also included the development of qanāts in Persia and Armenia, as well as sophisticated aqueduct systems in the Roman Empire.13