As CWatters said, best to get a spark to tell you what he wants where, sizes and positions of cables etc, you do the digging etc and then he comes back to connects it all up. After it is all inspected then you can cover it up and make good.
I would not like to sign off something I did not specify, route etc. For all I know you may have buried the cable 50mm under the ground when I asked for it to be 600mm deep