eli5 why are manhole covers in the middle of the road and not on the sidewalk?

Question

eli5 why are manhole covers in the middle of the road and not on the sidewalk?

In: 622

Answer 1

I work in utilities: manhole access to the sewer has to be a certain distance from each other, as well as at any change of direction in the sewer line. The reason they’re in the road and in alleyways (where you have them) is for access reasons. Checking flow up and downstream of problem areas for instance. Most sewer mains are centrally located for easier tapping for new service lines. In a lot of places, the street was there before the sidewalk was ever planned, so that’s where the Main is.