When were sewers invented?

Question: When were sewers invented!?

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Best Answer - Chosen by Asker:

the oldest sewers known are from the ancient indian cities of mohenjo daro and harappa!.

http://en!.wikipedia!.org/wiki/Indus_Valle!.!.!.Www@QuestionHome@Com

The earliest known use of sewers was in the Indus valley civilization (~3000BCE)!.!.!.!.!.!.but it would be harder to say when exactly they were invented!.Www@QuestionHome@Com

Excavation of the Orkney Islands found a sewer system dating back to 3000 BCE!.Www@QuestionHome@Com