Drainage system of harrapan civilisation

The Harappan civilisation was one of the earliest and the most advanced civilisation in the world. The civilisation was spread in the cities of the Sind in Pakistan and Gujarat, Rajasthan, Haryana and Punjab in India. The civilisation flourished in the area with the development of many cites like the Harappa, Mohenjo-Daro, Lothal, Cholistan and many others.

One of the most distinguishing and unique features of the Harappan cities was the drainage system. All the cities had highly advanced carefully planned drainage structures. In the Lower town of Harappa and other important cities, the roads and streets were laid out along a grid network. All of them intersected at right angles. It is structured such that the streets with drain network were laid out first and then houses built along them. It can be concluded that people were very particular about the removal of waste. The drains were covered in most of the places.

Every house in the street was connected to the drain network. The main channels of the drain were constructed with bricks set in mortar and were covered with loose bricks. This ensured the cleaning of the drains and to ensure they would not become clogged. In some places, limestone was used for the covers.

All the house drains first emptied into a sump or cesspit which allowed the sedimentation of the solid matter and the remaining wastewater flowed out into the street drains. All the long drainage channels had sumps at regular intervals for cleaning. Drainage systems were not unique to the larger cities. Such excellent drainage networks were found in smaller settlements as well.