In reality, it is extremely ...
Published by Arnold Liu, CEO & Scientific Director at Quantum Dynamics, Inc.
In reality, it is extremely likely that the location has been seeping/leaking for years -- which is typical for the progression of a pinhole corrosion pit leak to full catastrophic blow out that becomes surface visible. Per a recent AWWA study, in the USA the average water distribution system leak is about ~20%.
(While the energy pipeline industry is certainly not laudable for its leaks, were it to leak at such high levels as the water industry it would be shut down as a serious environmental hazard.)
Early low level detection, determination of leakage rate / prioritization, and repair is the most efficient means of distribution system maintenance -- and the cheapest and most available source of "new water".
As mentioned by in another responder to your question, distribution systems are usually supplied in sections. Lowering water main measurement uncertainties and large data set analysis will be necessary for long term distribution system maintenance and efficiency.
See attached papers on pipeline leak detection and the first section of a proposal addressing the specific water distribution system problem.