For example the sewer easements E-1 and E-2 shown at the rear of these blocks.
These easements are created when the land is subdivided.
However if you are buying an old block of land you may discover that even though there is no formal easement on the title there may be pipes or cables that need to be protected.
For example if a water,sewerage or electricity utility has used the land for 20 years or more then an easement by prescription may have been created.
I have had several personal experience of discovering prescribed easements that were initiated many years ago when local goverment areas were much smaller than now.
As everybody knew one another many permits to lay services were simply a handshake arrangement.
Worked well at the time but can be difficult to sort out now.
The laws on prescribed easements do vary from state to state so I recomend you consult a local property lawyer.