One of the drawbacks of owning an older home is that things will start to break down and you will have to start doing some pretty extensive repairs to keep your plumbing and other services running. One of the bigger jobs that will need to get done at some point is main line excavation and repair. Your main line is what connects your home to the municipal water supply and it was part of the original plumbing when your house was built.
If you bought a home that was built in the 70’s or even earlier then you have plumbing that is 50 years old or more. Your main line is probably a large copper pipe and while copper can last for years if you have acidic earth or water coming through it will start to corrode and you have leaks. The pipes can become blocked or damaged from tree roots. Sediment builds up after 50 years and you start to lose your pressure. Once the damage has taken hold then you will start to have water leak onto your property. This is NOT a do it yourself project you need a master plumber like Shore Plumbing with the tools and equipment to get your plumbing repaired.