Why Your Water Bill Suddenly Doubled (Hint: It's a Leak)
Open your water bill expecting the usual number and see it's nearly double, and your first thought is probably that the utility company made a mistake. In most cases, they didn't. A sudden, unexplained jump in water usage almost always points to a leak somewhere in your home, and tracking it down is more straightforward than it might seem.
Step 1: Check your toilets first
Toilets are, by a wide margin, the most common source of a silent water bill spike. A worn flapper that doesn't seal fully can leak hundreds of gallons a day without ever overflowing or making an obvious sound. Here's a simple test for each toilet in your home:
- Remove the tank lid and add a few drops of food coloring to the tank water.
- Don't flush. Wait about 15 minutes.
- Check the bowl. If any color has seeped into the bowl without a flush, the flapper is leaking and needs replacement.
Because this is such a common and inexpensive fix, it's always worth checking first before assuming something more serious is going on.
Step 2: Check your irrigation system
If you have a sprinkler or irrigation system, a cracked line, a stuck valve, or a zone that's been accidentally left running longer than intended can use a startling amount of water very quickly. Walk your yard looking for any soggy patches, unusually lush green areas, or standing water near valve boxes, and double check your irrigation controller's schedule to make sure nothing is set to run more often or longer than you intended.
Step 3: Check for hidden pipe leaks
If your toilets check out fine and irrigation isn't the culprit, the next step is checking for a leak elsewhere in your plumbing, which may not be visible at all. Common but easy-to-miss spots include:
- Supply lines under sinks
- Connections behind the washing machine
- The water heater's fittings and drain valve
- Outdoor hose bibs, especially after a hard freeze
Step 4: Run the meter test
If you've checked the obvious spots and still aren't sure, the water meter test settles the question definitively. With everything in the house turned off, including all fixtures and appliances, check whether your meter's leak indicator is spinning, or note the reading and check again after 30 to 60 minutes with no water used. Any movement confirms water is flowing somewhere it shouldn't be, even if you haven't located the exact spot yet.
Putting it all together
Working through toilets, then irrigation, then hidden pipe leaks in that order makes sense because it moves from the most statistically likely and easiest to check, to progressively less common and harder to spot. Most spiked water bills get solved in step 1 or 2. It's the ones that make it to step 4 without an obvious cause that often point to something like a slab leak or an underground line issue.
If your meter test confirms a leak but you've come up empty checking the usual spots, it's time to bring in help rather than let the mystery (and the bill) keep growing. ProFlow Plumbing can track down leaks that aren't visible from a standard walkthrough, so you're not paying for water you'll never actually use.