My Mom has been away for the past 6-months, so we make weekly checks on her house. Her water bills have been outrageous and the Water Utility company says the water meter on the property is working fine. My brother did food coloring in both toilet tanks, as there are only 2 toilets (2 full bathrooms) in the house, and found no change in color in either toilet bowls. We even checked the shower-heads, under the sinks, kitchen, and all faucets, they are not dripping and we have not found any wet spots. This empty and unoccupied house has consumed 8,000-gallons, 7,000-gallons, 10,000-gallons, 2,000-gallons, 2,000-gallons, and yesterday we got another water-bill for 5,000-gallons. My brother and I are out of ideas and places to check in the house. Please, How can we find this leak and stop it.

This empty and unoccupied house has consumed 8,000-gallons, 7,000-gallons, 10,000-gallons, 2,000-gallons, 2,000-gallons, and yesterday we got another water-bill for 5,000-gallons.
UNBELIEVABLE !! First you let Mom go away without shutting off the water to the house and even after receiving those outrageous water bills you still let the water run for months. Without shutting it off.
The water bills should be on you and not Mom. It's your lack of concern that kept the bills on coming.

My brother and I are out of ideas and places to check in the house To repair a leak you must localize it first. To check the service line shut off the house at the house shutoff. Check 6the little pointer in the meter. N It should not be moving, If it is the leak's in the underground line between the meter and the house. Little pointer still? Then we move on tom the house. Is it on a slab or does it have a basement? Now shut the hot water off at cold water shutoff on the heater. Pointer moving? If no then your leak is in the hot water system. If it still moves the leak is in the cold water section. Do those tests and let me know if this is a slab house and let me know what you've found. Good luck, Tom

Thanks speedball1 for your quick response and for our excellent troubleshooting recommendations!

Sorry I should have provided more details in my initial post >>

The water meter is right on the lot-line. The house sits on a slab and is located in Broward County FL. The alarms inside our head only started going off after we received the 2nd Bill/August 7,000-gallons - because we thought the previous high bill was for consumption prior to Mom leaving. We then asked the City who handles the Water-Billing to check the water-meter - not once but twice - they said the water meter was spinning intermittently. However, when my brother or I watched the water-meter it didn't move at all - so we did the food coloring in the toilet tank - which were both negative. Also we turned off the water under each of the toilets and under all the sinks including the kitchen.

By the beginning of October, following the 10,000-gallons consumed bill, I contacted the City and requested water-service be shutoff because we can't find any leaks and suspected someone was stealing the water. This gets weirder - then comes the 2000-gallons bill - which I assumed it was for the pre-shutoff leak-consumption. Then a second 2000-gallons consumed bill arrived in Nov. The reader's digest version: the City says that they only locked the water-meter, their Dec bill for 5000-gallons consumed - is for water consumption that is bypassing the meter - their translation, there is a leak inside the house!!

XTRA WEIRD PART >> Apparently, when the City shuts-off water service, it's only the water-meter that is locked, and water can still flow to the home << We personally had never heard of such a thing - so this is why I've posted our SOS on the board. In my mind if the City shuts off service - where is the water coming from??

Of note: my brother pointed out to the City - if there is leaking - how comes it goes up, up, up, then down, down, then up again...

Thanks for all the information. Yeah! Very weird !

Apparently, when the City shuts-off water service, it's only the water-meter that is locked, and water can still flow to the home
This simply can't be true. The water enters the meter from the city main. There is no bypass. The shut off valve's on the city side of the meter.(see image) and has provisions to place a padlock on the shutoff valve,(see image) To bypass the meter and allow water to enter the house without being metered sets the city up for everyone to bypass the meter and just steal the water. That doesn't make sense. How about taking a picture of the meter so I can see this bypass.

my brother pointed out to the City - if there is leaking - how comes it goes up, up, up, then down, down, then up again... What did the city say? Back to you, Tom