Surely projects like this could (should?) share their infrastructure with other utilities - shouldnt there be wifi/telecoms and water? gas and elec running through those tunnels?,(reply>), sandham I'd imagine interference would be a big concern. Being near high-voltage transmission lines is a pretty nasty environment for any kind of electronics, and I can't imagine electricity and water mix well either.<br><br>Keeping high voltage stuff isolated is probably the safest solution.