he ancient Indus Valley Civilization of Northwest South Asia, including Pakistan and parts of India, was prominent in hydraulic engineering, and had many water supply and sanitation devices that were the first of their kind.Among other things, they contain the world's earliest known system of flush toilets. These existed in many homes, and were connected to a common sewerage pipe. Most houses also had private wells.City walls functioned as a barrier against floods.Lothal was a port at the Arabian Sea with a dockyard