One of the first stages in building the city is the provision of water, we should take the opportunity while the site is still empty to do as much of the subterranean work as possible, since if subsidence occurs it will not damage any surface buildings.
If we have a square plot of 640 acres, we can put in a water ring main 1 mile in diameter, the pipe itself will have a diameter of approx 100", depending on the tunnelling machine.
The tunnelling machine will cut a tunnel through the ground as deep as possible, lining the tunnel with concrete to form the pipe as it goes, this machine should be remote controlled so that no lives are put at risk during construction, we do not have the ability to make a fully autonomous machine yet.
After making the ring main, the machine will make the sewer system connecting to an underground methane digester power station followed by a utilities main for electrical and fibre optic cables.
I don't think we need a gas distribution network.
We might think about installing a hot water main for geothermal space heating in buildings and greenhouses, the cost of geothermal will mean this will not be fully implemented for 10 years or more.
When all subterranean work is done the machine will come to the surface to be refitted to perform other construction tasks.
This will be the first ring main, if the city buys land to grow to 4 square miles then a second concentric ring main of 2 mile diameter will be built, and linked to the first.
This ring main will double as a reservoir, but if demand grows, a larger separate reservoir will be needed.
