Just as an aside, Bryan, Taupo(in NZ) is the centre of most of the North Island National Grid System, Energy is Generated here and it is also Distributed all around the North Island, from here.
220kV would be the lowest of the Line Voltages that carry energy up to Auckland and voltages of 330kV and 440kV have been used and are still in operation.
The biggest problem, Bryan, is the fact that these cables should have been Under-Grounded, years ago!, and the fact that they have not, doesn't say a lot for OSH or Transpower, over here.
With all of the advances in URD and XLPE cables(for ALL Voltages up to 2MV), you'd think that the Authorities could at least afford to U/G a small piece of Grid wiring.
Look at the price of Electricity, half of them could buy the whole darn system!!.