In the UK, the Ordnance Survey produces an overlay of power lines, large and small, on 1:250,000 and 1:50,000 maps - there is also a digital database showing all the wires and most masts and wind turbines.. Apps like sky demon and Runway HD will warn of wires.
Back in the last C, we would spend ages over-marking the lines you mention Crab, 'cos they weren't too easy to see, especially at night.
Shy: did we have a master wires map in planning, for the ones that missed the print?
I remember the wire indicator- by your right knee?
CG