Too Much Water!!!

More problems in our house.  We have a water leak somewhere in the house but we cannot find it.

Last week, the water meter guy knocked on my house door to tell me there was a problem with the reading.  A couple months ago I used only 4 cubic meters of water.  Last month it read 23 cubic meters.  I just checked the meter today and in just 13 days, I used about 15 cubic meters of water.

This is impossible since my roommate and I are never home but both of us noticed our water pump going off every night (it normally goes off every 2-3 days).

I did some calculations and figured roughly 850 liters of water is being leaked PER day (about 187 gallons of water).  We have no idea where the leaking water is going.  We thought maybe the pipes are leaking.  If so, it would have to be below the house.  If it was leaking along the walls of the house, we would be able to see the water damage.

I am suspecting that the water might possibly be siphoned off by one of the neighbors (Yes this does happen in Vietnam).  The water usage increased exactly at the same time my neighbor got new tenants.  Just a suspicion at this time but I will know more clearly on Monday.