Over time, holes or cracks – caused by corrosion from the soil, moisture, or earthquakes – can develop in a water main pipe.
Water pipes are subject to pressure changes. Eventually, a breach in the water main will result in a water leak that reaches the surface. Depending on where the breach occurs, a leak can manifest on the street, in your yard, or even the basement of your home. A water line break can also allow contaminated water to enter your home. If this this occurs, it is not safe to consume tap water in your home.
Most houses have a shutoff valve that can be used to stop the flow of water from the main in an emergency. In many cases, your public utility will shut off water flow in an emergency. But if not, you can cut off the water flow yourself. The homeowner shutoff valve is typically located next to the water meter) and requires a water meter key.