Yes, I agree with that the drainage system in Harappan cities which indicates the town planning. I can cite the following reasons in support of my answer.
•The drainage system needed a planning for its execution. It seems that first drainages were laid out and then houses were built along with the drains. Every house was supposed to have at least one wall along a street to allow the domestic waste water to flow out in the street drains. The plans of the lower town show that roads and streets were laid out along an approximate grid pattern, intersecting at right angles.
•It appears that human settlement was made by planning from the beginning. The city was restricted to a fixed area on the platforms.
•Bricks, sundried or baked, were of standard ratio. The length and breadth of bricks were of four times and twice the height respectively These bricks were used at all the settlements of the Harappan Civilisation.
