A water bill that suddenly doubles in Covina is almost always caused by a running toilet, a hidden leak in a supply line or slab, or an irrigation leak - not by the water district raising rates. If your usage jumped from a normal 6-8 CCF to 15 or 20 CCF in one billing cycle, something in your home is losing water continuously, and it will keep costing you until it's found.
Below we walk through how to confirm the problem with your meter, the specific culprits we see most often in Covina homes, and when it makes sense to bring in a professional instead of hunting for it yourself.
The short answer: what a sudden water bill spike usually means
A sudden high water bill in Covina means water is leaving your system somewhere between the meter and your fixtures, and the leak is usually silent. Toilets account for roughly 30% of indoor water use, and a single flapper that fails to seal can waste 200 gallons a day - about 6,000 gallons a month, or 8 CCF on your bill. That alone can add $60-$120 to a Covina billing cycle depending on your tier.
Leaks are the other big category. A pinhole leak in a copper supply line, a cracked irrigation valve, or a slab leak under the foundation all push water out at a steady rate, 24 hours a day. The EPA estimates the average American home leaks about 10,000 gallons a year - enough to fill a backyard pool. In Covina, where many homes were built between 1955 and 1985, aging galvanized and copper lines make that estimate conservative.
Before you assume the worst, rule out the easy stuff: a toilet running, a hose left on, a pool auto-fill stuck open, or a water softener regenerating more often than it should. If none of those apply, you have a real leak.
How to check your meter to confirm a leak
Your water meter is the fastest lie detector you have. Here's the test we run on every call before we open a wall.
- Shut off every water-using appliance and fixture. No faucets, no dishwasher, no washing machine, no irrigation, no pool fill.
- Find your meter box - usually near the sidewalk or in a front planter. Covina Water meters are read in CCF (hundred cubic feet); 1 CCF equals 748 gallons.
- Watch the low-flow indicator - the small triangle or dial on the meter face. If it's spinning with everything off, water is moving.
- Write down the reading and wait 30 minutes. If the number changed, you have a leak. If it didn't, the problem is intermittent - usually a toilet that only runs sometimes.
If the indicator spins, shut off the main valve at the house. If the meter stops, the leak is inside your plumbing. If it keeps spinning, the leak is between the meter and your shutoff - that's the water district's side, and you should call Covina Water directly before paying a plumber.
For homeowners who want the leak pinpointed without tearing into walls or concrete, leak detection Covina CA uses acoustic listening, thermal imaging, and pressure isolation to find the exact spot. We do this on almost every high-bill call, and it usually takes under two hours.
The most common causes of a high water bill in Covina
In our experience across Covina, Charter Oak, and the surrounding San Gabriel Valley, the causes fall into a predictable order. Here's what we find, ranked by how often we see it.
1. A running toilet
This is the number one cause of a sudden high water bill in Covina homes, and it's the cheapest to fix. A worn flapper, a misadjusted fill valve, or a stuck float lets water trickle from the tank into the bowl continuously. You often can't hear it. Put a few drops of food coloring in the tank, wait 15 minutes without flushing, and check the bowl. If color shows up, the flapper is leaking. A $10-$25 flapper and 20 minutes of work usually solves it.
2. A leaking irrigation system
Covina's clay-heavy soil shifts with our wet winters and dry summers, and that movement cracks drip lines, pops sprinkler heads, and stresses valve bodies. A single broken sprinkler head can waste 15-20 gallons per minute when the zone runs. Check your irrigation controller for zones that run longer than they should, and walk the yard while each zone is on. Look for soggy patches, greener grass in one spot, or water pooling at a valve box.
3. A slab leak
If your home sits on a post-tension or conventional slab - which describes most Covina tract homes built after 1960 - a pinhole in the copper under the floor can lose 1-5 gallons per minute. That's 1,400-7,000 gallons a day, and it shows up as a hot spot on the floor, the sound of running water when nothing is on, or a crack in the tile. slab leak repair Covina CA is a specialized job: we locate the leak, isolate the line, and either reroute or repair it with minimal concrete cutting.
4. A failed water heater or softener
A water heater with a failed T&P valve or a corroded tank can leak steadily into a pan or onto the garage floor. Water softeners stuck in regeneration cycle can dump 40-80 gallons per cycle, several times a day. If your softener runs at odd hours or your water tastes salty, that's a clue. water heater repair Covina CA covers both the leak and the pressure issues that cause it.
5. A hidden supply line leak
Pinhole leaks in copper, failing galvanized pipe, and loose compression fittings behind cabinets or in the attic all drip continuously. You may see a stain on drywall, a warped cabinet floor, or a musty smell before you ever see water. If your home still has original galvanized pipe, this is a when-not-if problem - whole home repiping Covina CA is the long-term fix.
Covina-specific reasons your bill climbs
Covina's housing stock and water chemistry create a few patterns we see over and over. Homes in plumbing in Downtown Covina and the older neighborhoods near Citrus Avenue often still have 1950s-60s plumbing with original shutoff valves that no longer seal, so a slow drip at the main is easy to miss. The water here is hard - typically 10-15 grains per gallon - which scales up water heater tanks, narrows pipes, and shortens the life of toilet fill valves.
Summer irrigation is the other big driver. From June through September, outdoor use can triple a Covina household's consumption. If your bill spikes in July and August but normalizes in October, irrigation is the likely cause. If it spikes in November or December - when nothing is being watered - that points hard at a toilet or a slab leak.
We also see a cluster of high-bill calls in plumbing in Charter Oak where 1960s ranch homes have long irrigation runs and aging copper under the slab. Same story in plumbing in West Covina just across the border, where the housing age and soil conditions are nearly identical.
What to watch out for when chasing a high water bill
A few mistakes cost Covina homeowners real money every year. Avoid these.
- Assuming it's the water district's fault. Covina Water will re-read a meter on request, but rate increases are public and gradual - they don't cause a 2x jump in one cycle.
- Ignoring a slow toilet leak because you can't hear it. The food-coloring test takes 15 minutes and rules out the most common cause.
- Cutting into a slab before locating the leak. Jackhammering the wrong spot is expensive and unnecessary. Acoustic and thermal detection pinpoints the leak first.
- Replacing a water heater when the real problem is pressure. If your home's pressure regulator has failed and you're seeing 100+ PSI at the hose bib, a new heater will fail too.
- Waiting for the next bill to confirm. A slab leak at 3 gallons per minute wastes 130,000 gallons a month. Two months of waiting can cost more than the repair.
If you're not sure where to start, our team at A1 Plumbing Covina CA handles plumbing Covina CA calls every week that begin exactly this way - a confusing bill and no obvious puddle.
When to call a professional
Call a licensed plumber when the meter test confirms a leak you can't see, when you hear water running with everything off, when you feel a warm spot on the floor, or when your water pressure has dropped alongside the bill. Those four signs point to a hidden leak, and the longer it runs, the more damage it does to your foundation, flooring, and framing.
We handle these calls daily across Covina and the surrounding cities. We locate the leak first, show you what we found, and give you a flat price before we start. If it's a toilet flapper, we'll tell you it's a toilet flapper - we're not going to sell you a repipe for a $20 part.
For after-hours emergencies - a burst line, water pouring out from under the slab, or a shutoff valve that won't close - our emergency plumber Covina CA line is answered 24 hours a day.
Frequently Asked Questions
Why is my water bill suddenly so high in Covina CA?
The most common cause is a running toilet, which can waste 200 gallons a day. Other frequent causes are irrigation leaks, slab leaks, and failed water heater valves. Run the meter test with everything off - if the low-flow indicator spins, you have a leak.
What causes a sudden high water bill in Covina homes?
In Covina specifically, aging copper supply lines, hard water scaling toilet valves, and shifting clay soil cracking irrigation lines are the top three. Homes built between 1955 and 1985 are the most likely to see a spike from a hidden leak.
How do I check for a water leak in Covina, California?
Shut off all water, find your meter, and watch the low-flow indicator for 30 minutes. If it moves, shut off the main at the house. If the meter stops, the leak is inside. If it keeps spinning, call Covina Water - that section is their responsibility.
Can a running toilet cause a high water bill in Covina CA?
Yes, and it's the most common cause we find. A leaking flapper wastes 200 gallons a day - about 6,000 gallons a month, or 8 CCF. At Covina's tiered rates, that's typically $60-$120 added to a single billing cycle.
How much does leak detection cost in Covina?
Typical 2026 pricing for residential leak detection in the Covina area runs $250-$450, depending on whether it's a slab, wall, or yard leak. Most jobs take 1-2 hours, and we credit part of the detection fee toward the repair when you hire us to fix it.
Get help with plumbing in Covina
If your water bill spiked and you can't find the cause, we'll find it for you - usually the same day. One call, one visit, and you'll know exactly what's leaking and what it costs to fix.
Call A1 Plumbing Covina CA at 626 687 0334 to schedule leak detection or a high-bill inspection.