Question

why do you think that separate pipes are used for sewage and rainwater

Answer 1

The main purpose of a storm sewer is to carry away excess rain, hence the name “storm” sewer. Once the rainfall flows through the opening of the storm sewer, it travels through underground pipes and drains to the ocean or nearby creeks, canals or rivers, as mentioned.

Answer 2

Yes, separate pipes should be used for sewage and rainwater. We cannot use sewage for household works, but we can use rainwater for many purposes and if not in use today, we can conserve raineater for future use. So, we should not mix sewage and rainwater .