Why Did My Water Bill Suddenly Go Up?

By Cypress CA Plumber · October 16, 2026

A water bill that jumps without explanation is often the first sign of a hidden leak. Here's how to track it down.

You open the water bill and it's noticeably higher than last time. Nothing has changed in the house. No guests, no new pool, no extra laundry. In Cypress and the surrounding cities, where many homes are 50 or 60 years old, that's often how a hidden leak first makes itself known.

Rule out the obvious first

• Billing period. Check whether this bill covers more days than usual.
• Season. Summer irrigation can raise use a lot, especially with lawns.
• Rates. Water agencies periodically adjust rates; compare the usage figure, not just the dollar total.
• Household changes. More people at home, a new appliance, a filled spa.

If none of those explain it, look for a leak.

The most common hidden causes

1. Running toilets. The single most common cause. A worn flapper lets water trickle from the tank into the bowl all day and night, often silently. Test it: a few drops of food coloring in the tank, wait 15 minutes without flushing. Color in the bowl means a leak.

2. Irrigation leaks. A broken sprinkler head, a cracked lateral line or a valve that doesn't fully close can waste a lot of water, often unnoticed because it runs at night. Look for soggy spots, unusually green patches, or water running down the gutter in the morning.

3. Slab leaks. A leaking water line under the concrete floor - common in older Cypress homes. Signs include warm spots on the floor, the sound of running water and a water heater that runs constantly. See slab leak detection.

4. Service line leaks. The line between the meter and the house can crack or corrode, leaking into the yard.

5. Dripping faucets and showerheads. Individually small, but they add up.

6. Water heater leaks. A relief valve that keeps discharging or a tank that's started to weep.

7. Water softener or filtration problems. A softener stuck in a regeneration cycle can send water down the drain continuously.

The meter test

1. Turn off all water use: faucets, toilets, appliances, irrigation controller, ice maker.
2. Find your water meter, usually in a ground box near the curb.
3. Look at the low-flow indicator (often a small triangle or star) or note the reading.
4. Wait 30 to 60 minutes without using water and check again.

If the meter moves: there's a leak somewhere on your property.
Close the main shutoff at the house and check again. If it still moves, the leak is between the meter and the house, or in irrigation that branches off before the house valve. If it stops, the leak is inside the house - toilets, fixtures, the water heater, or under the slab.

Narrowing it down inside

• Do the food coloring test on every toilet.
• Check under every sink and around the water heater.
• Feel floors for warm spots, especially along hot water runs.
• Listen quietly at night for running water.
• Check the softener for constant cycling.

Drought and conservation

Southern California goes through regular droughts, and water agencies sometimes set conservation targets or restrictions. A hidden leak makes it harder to stay within them. Fixing leaks quickly, upgrading old high-flow fixtures, and keeping irrigation in good repair all help - and California requires pre-1994 homes to have water-conserving fixtures anyway.

When to call

If the meter test shows a leak you can't find, or you suspect a slab or service line leak, a plumber with leak detection equipment can pinpoint it. See slab leak detection or emergency plumbing if water is visibly escaping.