Mohenjodaro — A Planned Urban Centre

The Planned Urban Centre of Mohenjodaro

Mohenjodaro is the best-preserved example of a Harappan city. Its most remarkable feature is that it was planned before it was built. The settlement was divided into two distinct parts: a smaller, higher western section called the Citadel, and a much larger, lower eastern section called the Lower Town. Both were walled, showing a clear separation of space.

How Planning is Evident

1. Platforms and Labour: The Citadel was built on a mud-brick platform to raise it above the floodplain. The Lower Town also had buildings constructed on platforms. The sheer scale of labour required for these foundations shows planning.
   • If one labourer moved 1 cubic metre of earth per day, the total effort to build the foundations alone was:

    This means **4 million person-days** of work were needed, indicating a massive, organised labour force.

2. Standardised Bricks: All bricks, whether sun-dried or baked, followed a fixed ratio. This standardisation was used across all Harappan settlements.

* Let the height of a brick be $h$.

* Then, the breadth $b = 2h$ (twice the height).

* And the length $l = 4h$ (four times the height).

* The standardised ratio is therefore:

3. Grid-Pattern Streets: Roads and streets in the Lower Town were laid out in an approximate grid pattern, intersecting at right angles. Drains were laid along these streets first, and houses were built afterwards, ensuring every house could connect to the street drain.

The Drainage System

The drainage system is one of the most distinctive features of Harappan cities. It was carefully planned and built.

• Main channels were made of bricks set in mortar and covered with loose bricks for easy cleaning.
• House drains first emptied into a sump or cesspit. Solid matter settled here, while waste water flowed out into the street drains.
• Long drainage channels had sumps at intervals for cleaning.
• This system was not limited to large cities; smaller settlements like Lothal also had drains, though houses there were made of mud bricks while drains were made of burnt bricks.

Domestic Architecture (Lower Town)

Houses in the Lower Town show a concern for privacy and comfort.

• Courtyard: Most houses were centred on a courtyard, which was the centre of activities like cooking and weaving.
• Privacy: There were no windows on the ground-level walls. The main entrance did not give a direct view of the interior or the courtyard.
• Bathrooms: Every house had its own bathroom, paved with bricks, with drains connected to the street drains. …