presenting the problem without connection to the bid, maybe I could have shared some insight. But the motive as presented have malice, what the use?

And for your info, our place of residence is in what you may consider a neighborhood of rich people who have the biggest houses (I think) and yet there is one corner with the same problem as you mentioned.

And you know what we did, we check the root cause including the problem of flow to the drainage. And guess what, it's not a problem anymore! It just happened that one of the villa here was occupied by our company as accommodation for the engineers. So we did our share of helping to solve the problem.