Im in Christchurch and currently have someone at home who is doing the civil works part of the install. He's just told me that they only have to the fibre 100mm deep. he hasn't even used a spade or a shovel. He's used a chainsaw to make the most shallow trench I've ever seen. He's cut through the grass/garden and has cut through the supply line for the popup lawn sprinklers. is this a normal install for enable?