Credited to Pakistan. Comparable drains are found at other Indus cities, including Harappa in Pakistan and Dholavira and Rakhigarhi in present-day India, so the system belongs to the Indus civilization as a whole. Mohenjo-daro is the best-preserved and most cited example.
How it began
Mohenjo-daro lies in the Larkana District of Sindh, Pakistan. It was built about 2500 BCE and was one of the largest cities of the Indus civilization, with an estimated population of at least 40,000. UNESCO describes it as a carefully planned city of the 3rd millennium BCE with a drainage system and public baths. According to Britannica, most homes had washrooms and the city had an extensive sewage system.
How it works
Houses drew water from wells, and many had a washing platform and a toilet or waste hole. Waste water ran through a clay brick pipe into a shared brick drain. House drains joined wider public drains laid along the main streets, built of precisely laid bricks and often covered, with openings at intervals for cleaning and inspection. Some drains fed soak pits that were emptied from time to time.
What changed first
Britannica notes that Mohenjo-daro lacked grand palaces or monuments but had numerous baths and sewers, which suggests that its builders gave priority to cleanliness and sanitation. The Great Bath, a large brick tank on the citadel mound, is the best-known structure on the site.
What lasted
UNESCO treats the city as a key example of early urbanization in South Asia. Its water supply and sanitation devices are described as the first known examples of their kind, and the drains of the Indus cities are regularly cited as the earliest urban sanitation systems.
Where it stands today
The city was abandoned by about 1700 BCE and rediscovered in 1922. It became a UNESCO World Heritage Site in 1980. The ruins cover 240 hectares, of which about a third has been excavated. Rising saline groundwater, urban development and possible floods threaten the unbaked and baked brick remains.
