In general, it is common that public or private utilities are buried underground. Since overhead utilities can look unattractive, most utilities are buried underground to maintain aesthetic value.
When a lot of utilities are buried underground, it presents a hazard during excavation works by a contractor. Power cables can be accidentally damaged which causes electricity disruption, water pipes burst causes major water disruption and even worse, a gas pipeline can cause explosion ignited by the friction from the bucket of an excavator.