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.