You start to see a story in some of them.
This manhole shifted since the summit.
Storm drains, even right next to the summit have no seals at all. That because the gutter part can't be closed off, so why bother with the rest. Plus, if you are small enough, you can crawl in through the storm drains from another neighborhood. Train a racoon and strap a bomb to it.
This manhole was opened and then resealed.
And this guy went crazy even taping a water shutoff cover. This wasn't done consistently.