The answer to 'supply line leaking water' is that a leaking supply line is a common plumbing issue that can be caused by a variety of factors, including worn washers, loose connections, or a crack in the line. Symptoms may include water dripping or pooling around the supply line, low water pressure, or damage to surrounding surfaces.
In many cases, a leaking supply line can be repaired without too much difficulty by a homeowner. This may involve tightening connections, replacing washers, or even replacing a section of the supply line. However, if the leak is extensive or the cause is unclear, it's best to call in a professional plumber to diagnose and fix the issue properly.