Road Construction - Photography

A couple of months ago while I was walking through a street and got caught up with a road that was under construction. They were currently working on the gutter.

But something I saw amazed me. They had to make a gutter that passed through the normal road instead the usual sides. That road was blocked with a rope on the two sides.

As of then, was I wondering what they were up to. I tried to think about it but couldn't come up with any answer.

At the end, their aim was to divert the gutter to other direction.
I was able to take a couple of shots before leaving.