>> if the pipes were easily accessible. Also more accessible to damage from vandals and car crashes. And they would freeze in winter. And they would expand/c

>> if the pipes were easily accessible. Also more accessible to damage from vandals and car crashes. And they would freeze in winter. And they would expand/contract with temperature changes, leading to increased cracking etc. The only places that use above ground water/sewer pipes are those with unsupportive soils such as permafrost or deep sand that would cause breaks.