On a larger lot, the water main can have a lengthy run from the meter to the house, often under lawn, landscaping and a long driveway. When it leaks, the clues usually come slowly. It might be a strip of grass greener than the rest, a meter that moves with nothing on, pressure that fades at every tap, or a water bill that keeps climbing.
On a long run, guessing where to dig gets expensive fast. Locating the leak helps narrow it down, and the repair fits what's found. Depending on the line's condition, the contractor may recommend fixing one bad fitting where it failed or replacing a damaged section. If the line is failing along its length, replacement is on the table, and pulling a new line through with a trenchless method can save the driveway and the yard above it.
The water keeps running through the meter, and wet ground can shift under walkways and hardscape. You get the findings and the options in plain English, with the tradeoffs, and you make the call. A licensed contractor does the work when you say go.