How much would it cost to run water/drainage pipes across the country?

So that if a certain location receives a lot of rain, it can spread it equally to x number of locations close to it. The x would depend on how much rain the first location receives, and how much the other areas surrounding it already have in reserves. How much roughly do you think it would cost to create such a huge infrastructure? I was thinking perhaps 4 feet pipes running under every street, so again if that one area receives a lot of rain, it will just drain out in almost a circle from the area.