Several years ago I was working on water sites and they didn't even have accurate info about the stuff on their own sites. The head office staff thought they did though. Just the computers did not match reality. Running many of the sites was entirely reliant on the knowledge of site operators who were all about to retire. There was no younger staff being taught anything either.

The fibre is a special level of "fuck you", as the altnets are deliberately leaving the mapping as late as possible, to gain a competitive advantage.

I'm in the US and a few years back we had to replace our septic system.. Did all the usual stuff to contact utility companies to come mark the lines off.

The cable company we had has been bought out twice in my memory, who knows how many times before that. They marked a straight line from certain points around the front of the house.

Well guess who sliced through the cable with the very first excavator chunk out BACK.

The placement made no sense until you consider a tree that had been cut down and stump removed, on the close front side of the house vs the completely clear, easily dug up but farther to go back side. Looks to me like someone didn't want to deal with roots and too the easy way, but didn't change the reported line. I don't know how cable guys usually mark their lines but I thought it was weird he only had a clipboard and some measuring tape instead of like... A metal detector. Idk if the lines can even be picked up with one though.

Another time I noticed water visibly flowing underneath the house from front to back through the foundation bricks. NOT good. At all. Very bad, in fact, to have flowing water under your house.

Thanks to the grass growing extra tall, and the excessive amount of groundwater I was able to track down a leak to a little spurt of water maybe 3 inches high coming from the ground. Called the water company about a busted pipe.

Apparently they had two lines next to each other, one was a replacement and the other was supposed to be bypassed but apparently never got cut off. So when the old line eventually completely broke, it just started pouring water into the hillside which ran down to our house. Three crews working until about 5am. Water spraying a good 15 feet into the air.

So they new where the pipe was, but they didn't really know where the pipe was since their papers said the actual leaky pipe no longer existed.

Whenever groundwork is done you're supposed to apply for some kind of permit and part of that process is that they're supposed to tell you if there's any underground utilities.

I can't count the number of times though that our engineers have dug up a fiber line or something that we would demonstrably told was not there. It's great because sometimes you can see on the pavement that it's being dug up and resurfaced in a different material so there's obviously something down there, but the paperwork says, nope we just dug it up for no reason there's nothing down there go mad.