Discuss the silent feature of harappan civilisation

The planned drainage system was one of the most distinctive features of the Harappan cities. Historians believe that streets with drains were laid out first and then houses were built along them. Some features of the drainage system:

• Every house was connected to the street drain. House drains emptied themselves into the main drain.  
• The drainage system and drains were covered with bricks or stones. They were provided with inspection holes at regular intervals for cleaning.
• House drains first emptied into sumps into which solid matter settled and wastewater flowed into the street drains.
• The Harappan cities were generally divided into two main parts - the raised area; known as the ‘Citadel’, and the lower town. The Citadel was more in height because the buildings in it were built on mud brick platforms. This area was separated from the lower town by a wall. The Citadel had within its fold important buildings like the Great Bath, the assembly hall, the granary and the workshops. The lower town, on the other hand had residential dwellings.
• The main streets of the Harappan cities were built according to the grid pattern. They were built from north to south and from east to west.
• The houses built on the corners of streets were rounded in order to allow the passage of carts. The main road in the city ofMohenjo-daro was 10.5 meters wide and 800 meters long.
• The house drains relayed all the waste water to the drains built in streets.
• The streets were so designed as to cross the main road of the city at right angles, thus dividing the city into square or rectangular blocks.