Water leaks can be difficult to find, especially if they're hidden under concrete. If you suspect that you have a water leak, there are a few methods you can use to try and locate it. One way is to use a water meter to detect the water flow. Another way is to use a listening device or electronic detector to locate water under concrete. You can also use a moisture meter to detect water on the other side of walls or floors. If you're having trouble locating the water leak, contact a plumbing professional for help. They have the experience and tools necessary to find and fix water leaks quickly.