If we were to look at maps of when large portions of central hydraulics infrastructure was put in place in major Western cities, we would find that a lot of it was done more or less a hundred years ago. Suburbs, of course, much later.

When we buy car batteries, we buy them with given 'life expectancies' of roughly 2 to 4 years.

Pipes and lines have life expectancies as well. Series of freeze and thaw cycles, for example, that metal or terra cotta can endure and maintain integrity, for example.

Stuff is wearing out. A lot of that stuff was installed within a few decades. It's losing its integrity, and has not been upgraded.

If, on the other hand, someone could show me that a huge high percentage of water mains installed at various times -- some a hundred years ago, some fifty, and some twenty years ago -- were all failing together all of a sudden... now that would be remarkable.