Sophisticated Sanitation

In class we learned about the intense city planning discovered at Mohenjo-Daro (modern day Pakistan) in 1922 as part of the Indian Archeological Survey led by Sir Mortimer Wheeler. In his article, the “Sewers of Mohenjo-Daro”, published by the Water Environment Federation, Cedric Webster discusses the complex and impressive sanitation system the Harrapans at Mohenjo-Daro developed. He argues it was unrivaled until the sanitary sewers of Hamburg, Germany in 1842, at least some 1,800 years later. It took 5,000 years for sanitation systems to match those of Mohenjo-Daro.

He writes that almost all of the houses had bathrooms that were attached to sewers in the street. In addition, it was required that the bathroom would be in a room with a wall facing the street so it would be easy to access the sewer system. Some bathrooms were even on the second floor of houses.In this case, there were pipes (made of bricks) running down the side of the house to the sewers in the streets. These pipes were even “steeped” so sewage would flow gently from the plumbing into the sewer and not “splash a passerby”. The details of this system are really impressive. What were people doing for so many centuries when such a well-thought out system had once existed?

"large brick-covered sewer in center of street)

“large brick-covered sewer in center of street”

Once the sewage was in the street, it flowed through sewers in the middle of the way (as pictured below). The planners sought to be able to clean and perform maintenance on the sewer system and so they covered the sewer (anywhere form 12 to 24 inches deep) with loosely laid bricks. There were also “sumps” (basically man-holes), but these would likely have filled up completely with sewage so it would actually have been impossible to use them. Webster suggests they may have served as clarifiers, very early water treatment centers. Given that the city was rebuilt at least 9 times, according to Webster, the sewers had to be accessible so they could be raised with the new developments. Indeed, it seems that the mud-bricks, favored for all projects in Mohenjo-Daro were recycled and reused for subsequent sewer development.

Archeologists have also found what they call “a Great Bath Building”. They believe it was used in religious ceremonies. It may have included a mechanism that allowed for fresh water to be poured into the bath-vessel. Archeologists have uncovered many pottery and models in the sewers at Mohenjo-Daro.Some have decided this is evidence of children playing with toys in the bath.

Webster, Cedric. “The Sewers of Mohenjo-Daro.” Journal (Water Pollution Control Federation) 34 (1962): 116-123.