Anecdata, but I worked several years in infrastructure projects (and in the course of that cut numberless pipes, cables - both electricity and communications -

Anecdata, but I worked several years in infrastructure projects (and in the course of that cut numberless pipes, cables - both electricity and communications - and what not), the basic issue in my experience was the sloppyness with which the drawings of the utilities layouts were made or the use of "unreliable" references. A typical one, is the indication (on the drawing) that a cable is 30 cm from the border of the sidewalk, but in the - say - 30 years since that cable was laid down the sidewalk has been enlarged by 40 cm AND a new cable has been laid down at 30 cm from the new sidewalk AND this other new cable has not been added to the drawing (or it has been added to another drawing by mistake). So you go there, actually find "a" cable 30 cm from the sidewalk, believe in good faith that it is the one on the drawing, and next minute you cut the one now under the sidewalk. It is only a few years that GPS positioning is used for cable and pipes layout (which should give better "absolute positioning") but the issues about mis-labeling and mis-reporting (given also the number of different companies, particularly telecommunications ones that may lay new cables) have not changed much AFAIK. We once had a set of bored piles (Ø 1000 mm) for the foundation of a sustaining wall miss a high pressure large diameter (Ø600 mm) methane pipeline by millimeters (the drilling rig bit the steel pipe covering, making the actual metal of the pipe shiny). The explanation was that the people making the drawing and maintaining the pipeline took as reference the milestones of the road (that were replaced because a curve was added some kms before and shifted by 100 m) and gave our project the green flag because we were almost 100 m away from the pipeline.