Yes, NYC has an identical problem: most of those pipes were not documented or the documentation is lost. They're there, they know they are, they just don't know where.
Friend said the contractor called the city, who then accused him of working without a permit. And then after that was squared told him the pipe was abandoned. The contractor said okay I'm going to cut into it with a chainsaw. At which point they sent out an inspector and all hell broke loose.
City's maps showed the pipe running in the middle of the street. But it was under a row of 12 houses.
I find that hilarious. It's like they immediately assume fault, because they get used to having everything so perfectly documented, except the old technical documentation can be very imprecise. Heard stories like these, too.