Indus water and drainage

The system

Houses were equipped with bathing platforms of tightly laid brick, sloped to a corner, from which waste water ran through a channel in the wall into a drain in the lane outside. Lane drains fed larger covered channels beneath the main streets, built of brick with removable slabs and provided with inspection points and settling pits where solids could be cleared.

Mohenjo-daro, in ancient India (modern-day Pakistan), had hundreds of wells, some public and many within individual houses, built as cylinders of wedge-shaped brick that could be extended as ground level rose.

Scale and priority

The proportion of civic effort devoted to water is what strikes archaeologists. Drainage was built into the fabric of the streets rather than added, wells were maintained and heightened over centuries, and at Dholavira, in an arid zone, an enormous system of dams and reservoirs occupies a large share of the enclosed area.

By comparison, contemporary Mesopotamian and Egyptian cities concentrated monumental effort on temples and tombs. The Indus cities put it into water supply, drainage and, at Mohenjo-daro, the Great Bath.

Interpretation

The provision was general rather than confined to a wealthy quarter, which has been used to argue for a relatively broad distribution of resources — though the inference is contested, since house sizes do vary and absence of palaces is not proof of equality.

Whether the emphasis on bathing was practical, ritual or both is unresolved. The continuity with the importance of ritual purity and bathing in later Indian religion is often noted, and is suggestive rather than demonstrable across the intervening gap.