Recently, I got an exceptionally high bill for water consumption. I went to check my water meter, and saw that it rotates in a pace of about 200 cc per minute, even though all the faucets in my home are closed. So, I concluded that there is probably a hidden leakage somewhere in my home.
But then I did the following experiment: I closed the main faucet (the one just next to the water meter). The water meter immediately stopped rotating. I waited for 1 minute, and then opened the main faucet again. At that second, the water meter rotated very fast - it made about 400 cc in a second! After that second, it returned to its previous pace of 200 cc per minute.
Is there a physical explanation for this phoenomenon?
(Some details that may be relevant: I live in the 2nd floor in a 3-floor house. We get our water from the urban pool, located at the top of the hill in the center of town).