Homeowner water-use guide
Why is my water bill so high? Start with the most likely causes.
A high bill does not always mean a hidden plumbing leak. Hot weather, irrigation, guests, pool use, rate changes, longer billing periods, running toilets, broken sprinklers, water heater leaks, and underground supply-line problems can all increase the amount due.
This guide explains what to review first, how to check your water meter, how to test a toilet, and when unexplained water use may justify professional leak detection.
☎ Call (866) 227-6805Begin with the bill
Did water use rise, or did the price change?
The total amount due can rise even when household use changes only slightly. Water-rate increases, sewer charges, drought surcharges, tiered pricing, past-due balances, account adjustments, estimated readings, and a longer billing period can all make the bill look unusually high.
Find the line showing gallons, cubic feet, or another measure of consumption. Compare that number with the prior bill and, when possible, the same season last year. A summer bill is more meaningful when compared with another summer bill than with a winter bill.
Also calculate average daily use by dividing total consumption by the number of billing days. This can reveal whether the increase reflects actual daily demand or simply a longer billing cycle.
Questions to ask
- Was the billing period longer?
- Did the utility change rates?
- Was the previous reading estimated?
- Did irrigation schedules change?
- Were there guests or extra laundry?
- Was a pool or spa filled?
Normal increases
When higher water use may have a reasonable explanation
Hot weather and irrigation
California summers can sharply increase outdoor demand. Longer sprinkler schedules, new landscaping, hand watering, dry wind, and evaporation may all raise consumption.
Guests and household changes
More showers, laundry, dishes, and toilet use can noticeably increase daily water demand, even when no plumbing problem exists.
Pool or spa use
Filling, topping off, cleaning, backwashing, and evaporation can add substantial water use during warm months.
More laundry or cleaning
Frequent laundry, vehicle washing, pressure washing, or a change in appliance use may explain higher consumption.
Long billing period
A bill covering more days than usual may be higher even if the average daily use changed very little.
Reading correction
An estimated bill may later be corrected after an actual meter reading, producing a sudden adjustment.
Likely plumbing causes
Common sources of unexplained water use
Running toilets
A worn flapper, faulty fill valve, incorrect water level, loose chain, or damaged flush-valve seal can allow water to flow continuously from the tank to the bowl.
Dripping faucets
Worn cartridges, washers, seals, or valve seats can create a steady drip that continues day and night.
Irrigation leaks
Cracked underground lines, broken sprinkler heads, stuck valves, and controller mistakes can waste large amounts of outdoor water.
Water heater leaks
Water can escape from a tank, valve, fitting, drain connection, or relief line. Some leaks drain away before they become obvious.
Slab or underground leaks
Pressurized supply lines beneath concrete or between the meter and home can leak continuously and may cause warm floors, damp areas, or lower pressure.
Water-treatment equipment
A softener that regenerates too often, a reverse-osmosis system with a faulty shutoff, or another malfunctioning device can increase usage.
Meter test
How to check for unexplained water flow
- Turn off all known water use. Stop faucets, toilets, irrigation, laundry, dishwashers, ice makers, pool fill systems, and water-treatment equipment.
- Record the meter reading. Take a clear photo or write down the displayed number. Some meters have a small flow or leak indicator.
- Wait without using water. A short wait may reveal a large leak; a longer wait can reveal slower flow.
- Check the meter again. If it changed, water moved through the property during the test.
A meter test shows that water is flowing, but it does not identify the source. Automatic systems, appliances, irrigation, and hidden leaks can all cause movement.
Do not tamper with utility equipment
Do not force utility-owned valves, open sealed meter components, or enter unsafe or flooded meter boxes. Contact the water utility if the meter appears damaged, inaccessible, or inconsistent with the bill.
Toilet test
A silent toilet leak is easy to miss
A toilet may leak from the tank into the bowl without making much noise. Add a few drops of food coloring or a toilet leak-detection tablet to the tank, not the bowl. Do not flush. Wait to see whether colored water appears in the bowl.
If color appears, water is passing from the tank to the bowl. The flapper, flush-valve seal, chain, fill valve, or tank water level may need attention.
Signs of a running toilet
- The tank refills when no one used it.
- You hear hissing or trickling.
- The handle sticks or must be jiggled.
- Water moves in the bowl between flushes.
- The water level reaches the overflow tube.
Outdoor water use
Inspect irrigation and exterior plumbing
Run each irrigation zone
Look for broken heads, misting, weak coverage, pooling, geysers, or a zone that does not shut off.
Review controller settings
Check start times, watering days, seasonal adjustments, and duplicate programs that may be running unnoticed.
Look for wet ground
Persistent damp areas, unusually green patches, erosion, or soft soil can suggest an underground line or valve leak.
Inspect hose connections
Check hose bibs, timers, splitters, quick connectors, vacuum breakers, and attached hoses while under pressure.
Check pool autofill
A stuck or misadjusted autofill valve can continuously add water and conceal a pool leak.
Compare seasonal schedules
Manual or weather-based adjustments may increase run times more than expected.
Hidden leak signs
Clues that water may be escaping out of sight
Warm floor areas
A warm spot may suggest a hot-water line issue beneath a concrete slab.
Stains or bubbling paint
Ceiling stains, peeling paint, swollen drywall, or warped baseboards can indicate ongoing moisture.
Musty odors
Persistent mildew-like odors may develop where moisture remains trapped.
Pressure changes
A substantial leak can reduce available pressure, although pressure problems may have other causes.
Running-water sounds
Hissing, dripping, or flowing sounds when fixtures are off deserve investigation.
Meter movement
Unexplained meter movement can indicate leakage or automatic equipment operating unexpectedly.
Still cannot explain the increase?
Describe what changed, what you tested, and whether the meter moved. Ask about leak-detection availability in your area.
Pattern guide
Match the symptom to the next useful check
| What you notice | Possible source | Next check |
|---|---|---|
| Toilet refills by itself | Flapper, fill valve, chain, or water level | Perform a dye test |
| Bill rises mainly in summer | Irrigation, pool use, or outdoor watering | Review schedules and run each zone |
| Meter moves with everything off | Hidden leak, automatic equipment, or underground line | Confirm all automatic systems are off |
| Warm floor spot | Possible hot-water slab leak | Check meter movement and seek evaluation |
| Water near the heater | Tank, valve, fitting, or relief line | Find the wettest point without touching electrical or gas parts |
| Wet area in the yard | Irrigation, service line, or drainage issue | Check meter movement and irrigation activity |
Frequently asked questions
High water bill questions
Can a running toilet cause a high water bill?+
Yes. A continuously running or intermittently refilling toilet can waste water around the clock.
Can a small faucet drip matter?+
Yes. A steady drip continues day and night, and the total depends on the drip rate and how long it remains unrepaired.
Can irrigation leaks happen underground?+
Yes. Cracked lines and leaking valves may release water into the soil without creating an obvious spray.
Can a slab leak increase my bill?+
Yes. A pressurized supply-line leak beneath a slab can run continuously and may cause warm floors, dampness, or unexplained meter movement.
Can a water heater leak increase usage?+
Yes. A tank, fitting, valve, or relief-line leak can waste water, sometimes into a drain or pan where it is not immediately noticed.
When should I call a plumber?+
Consider calling when meter movement remains unexplained, the bill stays unusually high, visible damage appears, pressure changes, or a concealed leak is suspected.
Is California Water Help a plumbing company?+
No. California Water Help is an independent referral website and does not directly perform plumbing services.
How should I verify a contractor?+
Verify the provider's legal business name, license, insurance, written estimate, warranties, and service terms before authorizing work.
Related resources
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