Permitting and code - you start by getting permission to make a physical connection. The process for a small user (like a home) is probably pretty simplified, but for a large users like industrial and comercial locations, you go through a review on how you would impact the rest of the distribution system. You may be required to upgrade things (new sub stations, pipes, etc)
Physically connections - Sewer, water, and natural gas are probably hot tapped. The means you put a saddle on the pipe, then a valve, then a drill assembly goes through the valve, drills a hole on the pipe, then retracts and you close the valve. the distribution system is also build with redundancy, so they can possibly isolate certain legs and drain them if need by.
Electricity is done by the utulility company, but can be done live with certain protective measures.
I do not have any direct experience with telecom, but i imagine its similiar.
I'm an engineer at a manufacturing plant, but i used to be a construction worker and i've actually hot tapped water and sewer.
They're building a large Bass Pro Shops in my area, but the opening date was delayed. I spoke with a friend at the local municipal utility authority, and he told me they realized the sewer pipes weren't big enough to handle all the water flow and made them run a new line.
I'm trying to get more electricity into my manufacturing plant, I had to apply to the power company for a review of the new connection. They looked at the existing capacity on my leg of the grid and determined that i can take another 200A of the grid (at13.2kv) without impacting the other customers. they told me this is good because my 2nd option would be to run 5 miles of utility poles and install a new sub-station. option 1 is about $100,000 while option 2 would be about $4 million.
Water, sewer, drainage and cable are typically under the new roads. The developer has to find the nearest existing connection points that are sufficient to service the new homes and they connect there and construct new lines under the road.