Common signs include unexplained high water bills, damp or moldy areas, low water pressure, and the sound of running water when no faucets are on. You might notice water pooling on floors, discolored or greener grass areas, sinking yard spots, random potholes, or your water meter moving when it should be off.
One of the first signs is a sudden, unexplained spike in water bills—if your usage hasn’t changed but bills have increased significantly, it could indicate a hidden leak under your slab. Hot water line leaks often create warm spots on floors, which can be clear indicators especially when the rest of your floor feels cool. Visible mold around showers, tubs, baseboards, walls, or ceilings, plus musty odors, often indicate excess moisture from hidden leaks.