Why Is My Water Bill Suddenly High?

Opening your water bill and seeing a much higher amount than usual can be frustrating.

One of the first questions most homeowners ask is:

"Do I have a leak?"

Sometimes the answer is yes.

In fact, a sudden increase in your water bill is often one of the earliest warning signs of a hidden plumbing leak.

However, not every high water bill is caused by a major plumbing failure. Sometimes the cause is as simple as a running toilet, an irrigation system issue, or increased water usage around the home.

At Plunger Pros, we regularly help homeowners throughout New Braunfels, San Antonio, Schertz, Cibolo, Bulverde, Spring Branch, Canyon Lake, and surrounding communities track down the source of unexpectedly high water bills.

Let's discuss the most common causes, what you can check yourself, and when it's time to call a plumber.

Why Water Bills Suddenly Increase

Water bills generally increase for one of two reasons:

Increased Water Usage

or

A Water Leak

The key is determining which one is responsible.

Many homeowners immediately assume they have a major plumbing problem.

Others assume the water company made a mistake.

The truth is that both situations are possible, but in our experience, a sudden and significant increase often indicates some type of leak or plumbing issue.

The good news is that many of these leaks are relatively simple to identify and repair.

The Most Common Causes of a High Water Bill

Running Toilets

If we had to pick one cause, this would probably be it.

Running toilets are one of the most common causes of unexpectedly high water bills.

The problem is that many running toilets aren't obvious.

Homeowners often assume they would hear water running constantly.

In reality, some toilets leak slowly and quietly enough that they go unnoticed for weeks or even months.

Common causes include:

• Failed flappers

• Worn fill valves

• Improperly adjusted components

• Mineral buildup

A single running toilet can waste a surprising amount of water and significantly increase your monthly bill.

Water Service Line Leaks

The water service line is the pipe that carries water from the city meter to your home.

Because this line is underground, leaks often go unnoticed.

Signs may include:

• High water bills

• Low water pressure

• Wet areas in the yard

• Water meter showing flow when nothing is running

However, many service line leaks never surface at all.

We've located major underground leaks where homeowners had no visible signs other than an increased water bill.

Irrigation System Leaks

Irrigation systems are another common source of excessive water usage.

Problems can include:

• Broken sprinkler heads

• Underground irrigation leaks

• Stuck irrigation valves

• Incorrect programming

We've even encountered situations where irrigation controllers were accidentally programmed incorrectly, causing watering cycles to run much longer than intended.

This can dramatically increase water consumption without the homeowner realizing it.

Water Softener Problems

Many homeowners don't realize that water softeners can contribute to high water bills.

While water softeners normally use water during regeneration cycles, problems can occur when:

• A valve fails

• The system develops a leak

• The softener becomes stuck in regeneration

• Water continuously flows to the drain

Because the water often goes directly down the drain, the problem can remain hidden for extended periods.

Increased Household Water Usage

Not every high water bill is caused by a plumbing issue.

Sometimes water usage simply increases.

Common examples include:

• Guests staying in the home

• Filling swimming pools

• Summer water activities

• Additional laundry

• Increased outdoor watering

Before assuming there's a leak, it's worth considering whether water usage has changed recently.

How Can You Tell If It's a Leak or Increased Usage?

This is one of the most common questions homeowners ask.

The easiest place to start is your water meter.

Check the Water Meter

Your city water meter can provide valuable information.

Most meters have either:

• A leak indicator

• A flow dial

• A digital flow reading

Turn off all water fixtures in the home and make sure nobody is using water.

Then check the meter.

If the meter continues showing water flow, there is a strong possibility that water is being used somewhere in the system.

That usage may be caused by:

• A leak

• A running toilet

• A malfunctioning water softener

• An irrigation issue

• Another plumbing problem

Check Your Water Softener

Many modern water softeners include flow monitoring capabilities.

If the softener indicates water flow when no fixtures are operating, that's another clue that water is moving through the system somewhere.

This can be extremely helpful when narrowing down the source of a high water bill.

Signs of a Hidden Water Leak

One of the biggest misconceptions homeowners have is:

"If I don't see water, I don't have a leak."

Unfortunately, that's not always true.

Many of the largest leaks we find are completely hidden.

Common signs include:

• High water bills

• Low water pressure

• Warm spots on floors

• Sounds of running water

• Water meter movement

• Unexplained moisture

• Wet areas in the yard

Sometimes the only symptom is an increased water bill.

What About Slab Leaks?

A slab leak is a leak beneath the foundation of the home.

Because these leaks occur under concrete, homeowners often don't see water immediately.

Warning signs may include:

• High water bills

• Warm floors

• Reduced water pressure

• Water sounds with no fixtures operating

The longer a slab leak continues, the more damage it can cause.

How We Diagnose High Water Bill Complaints

When we arrive at a home for a high water bill investigation, our goal is to determine whether water is actually being lost and identify where it's going.

The process typically starts with:

Step 1: Check the Water Meter

We verify whether the meter is showing water movement when the home is not using water.

Step 2: Check Water Softener Flow

If a water softener is present, we evaluate whether it is showing unexpected flow.

Step 3: Perform a Pressure Drop Test

A pressure drop test helps determine whether the plumbing system can maintain pressure when all water usage is stopped.

If pressure drops unexpectedly, it often indicates a leak somewhere within the system.

This is one of the most effective methods for confirming hidden leaks.

Step 4: Locate the Source

Once we confirm a leak exists, we begin narrowing down its location.

Depending on the situation, this may involve:

• Leak detection equipment

• Fixture inspections

• Water service line testing

• Isolation testing

• Additional diagnostics

A Real High Water Bill Leak We Found in New Braunfels

Recently, we helped a homeowner in New Braunfels who was dealing with a very high water bill.

The homeowner was convinced they had a leak, but there was no visible water anywhere.

The home's plumbing system consisted primarily of PEX piping located in the attic.

All fixtures appeared normal.

No visible leaks were found.

However, the water meter was showing approximately:

10 gallons per minute

of continuous water flow even though no water was being used.

That is a significant amount of water loss.

Using our leak detection methods and equipment, we traced the problem back to the incoming water service connection where the service line tied into the home.

After excavating the area, we located and repaired the leak.

Once the repair was completed:

• Water flow dropped to 0 GPM

• The pressure test passed

• The leak was eliminated

The only sign the homeowner had before calling us was an unusually high water bill.

Can High Water Pressure Cause a High Water Bill?

Technically, yes.

Higher pressure means fixtures discharge water more quickly.

However, in most situations, high pressure alone is unlikely to cause a dramatic increase in your bill.

What we often see instead is that high pressure contributes to:

• Fixture failures

• Leaks

• Running toilets

• Water heater issues

Those secondary problems are much more likely to cause significant increases in water usage.

What Should You Do If Your Water Bill Suddenly Increases?

If your bill jumps unexpectedly, start with a few simple checks.

Check the Water Meter

Look for signs of continuous water flow.

Check Toilets

Running toilets are one of the most common causes of high water bills.

Check Outdoor Faucets

Verify no hose bibs or hoses have been left on.

Check Irrigation Systems

Make sure watering schedules are correct and sprinkler heads aren't damaged.

Check Your Water Softener

Look for unusual flow or signs that the system may be stuck in regeneration.

Call a Plumber

If you still can't determine the source, professional leak detection may be necessary.

The Biggest Misconception About High Water Bills

The biggest misconception is that a large increase in the water bill automatically means there is a massive plumbing leak somewhere in the home.

While major leaks certainly happen, many high water bill calls end up being caused by relatively simple issues such as:

• Running toilets

• Irrigation problems

• Water softener issues

• Minor plumbing leaks

On the other hand, homeowners often assume that if they don't see water, there can't be a leak.

Some of the largest leaks we find are underground, beneath foundations, or inside plumbing systems where no visible water is present.

That is why proper diagnosis is so important.

Don't Ignore a Sudden Increase in Your Water Bill

A sudden increase in your water bill is often your home's first warning sign that something isn't right.

Whether the cause is a running toilet, water service leak, slab leak, irrigation issue, or water softener problem, identifying the issue early can help prevent wasted water and larger repair costs.

If you're experiencing a high water bill and aren't sure why, Plunger Pros can help.

We provide leak detection, water service repairs, slab leak diagnostics, pressure testing, water softener evaluations, and plumbing inspections throughout New Braunfels, San Antonio, Schertz, Cibolo, Bulverde, Spring Branch, Canyon Lake, and surrounding communities.

Plunger Pros
Plumbing done the proper way
M45279
(830) 356-2141

Frequently Asked Questions

Why did my water bill suddenly double?

The most common causes include running toilets, water leaks, irrigation problems, water softener issues, or increased water usage.

Can a running toilet really increase my water bill?

Yes. A running toilet can waste a significant amount of water and is one of the most common causes of high water bills.

How do I know if I have a hidden water leak?

Check your water meter when no water is being used. If the meter continues showing flow, there may be a leak.

Can a water softener cause a high water bill?

Yes. A malfunctioning water softener can leak or become stuck in regeneration, allowing water to continuously flow to the drain.

Can a slab leak cause a high water bill?

Absolutely. In many cases, a high water bill is one of the first warning signs of a slab leak.

What should my water meter show when no water is being used?

Ideally, the meter should show no flow when all fixtures and appliances are off.

Can irrigation systems cause high water bills?

Yes. Broken sprinkler heads, leaking valves, and programming errors can significantly increase water usage.

Should I call a plumber if I can't find the cause?

Yes. If you've checked the obvious sources and your water bill remains unusually high, professional leak detection can help identify hidden problems.