There may well be some sort of "wayleave" requirement to allow access to the pylons and wiring.
It's interesting to note that these power lines were moved here at the request of Mr Mottershead. Beyond the Zoo boundary. They were originally sited in 'animal enclosure' > Ape House > Realm of the Red Ape. I'll see if I can find old pics showing them. Perhaps an opportunity to re-site again now using the new style less intrusive UK 'T'- Pylons?
First new pylon type constructed