Why Is My Water Bill So High? Common Plumbing-Related Causes for Collin County Homeowners

You open your utility bill and your jaw drops—your water bill is suddenly much higher than usual. If that sounds familiar, you're not alone. Unexplained spikes in water bills are one of the most common concerns we hear at Landry Plumbing from homeowners across Collin County.

While seasonal usage changes or rate adjustments can sometimes be to blame, more often than not, the culprit is hidden somewhere in your home’s plumbing system. This guide will help you identify the most common plumbing-related causes of high water bills, show you what to check for, and let you know when it’s time to call in a professional.

How Much Water Should Your Home Use?

Before diving into possible causes, it helps to understand what's considered normal. According to the EPA, the average American family uses roughly 300 gallons of water per day. For a family of four, that typically translates to 9,000 gallons per month.

If your bill reflects significantly more than that without a clear reason (like filling a pool or hosting guests), it’s time to investigate.

1. Hidden Leaks in Your Plumbing System

Small, slow leaks can waste hundreds or even thousands of gallons of water each month—without obvious signs. These hidden leaks are often the root cause of unexpectedly high water bills.

Common leak locations:

• Behind walls (supply line leaks)

• Under sinks

• Inside crawl spaces

• Underground or beneath slabs (see: What Is a Slab Leak?)

  
  

Signs of hidden leaks:

• Unusual dampness, mold, or mildew

• Warped floors or peeling paint

• Sounds of running water when nothing is on

• Spikes in your water meter even when all fixtures are off

  
  

Quick test: Turn off all water inside and outside your home, then check your water meter. If it continues to spin or move, you likely have a leak.

2. Running or Leaky Toilets

Toilets are one of the most common sources of water waste in a home. A running toilet can waste up to 200 gallons per day.

What causes it?

• A worn-out flapper valve

• Faulty fill valve

• Improper float adjustment

• Sediment buildup in the tank

How to check: Put a few drops of food coloring in the toilet tank. Wait 10–15 minutes without flushing. If the color shows up in the bowl, your toilet is leaking.

3. Dripping Faucets and Showerheads

A slow drip might seem minor, but it adds up. A faucet that drips once per second can waste over 3,000 gallons of water per year.

Likely causes:

• Worn washers or O-rings

• Corroded valve seats

• Loose parts or improper installation

Tip: Fixing a single leaky faucet is often a simple DIY job—but don’t wait too long. Multiply that leak by several fixtures, and the costs climb quickly.

4. Outdoor Leaks and Irrigation Issues

Leaks aren't limited to the inside of your home. Irrigation systems, outdoor spigots, and underground sprinkler lines can all be sneaky sources of waste.

Signs to watch for:

• Patches of extra-green or soggy grass

• Water pooling near exterior walls

• Hissing or bubbling sounds from the yard

Sprinkler issues that increase usage:

• Sprinklers running longer than needed

• Sprinkler heads aimed at sidewalks or driveways

• Broken or misaligned heads leaking continuously

5. Slab Leaks

A slab leak is a leak in the water lines that run underneath the concrete foundation of your home. These are harder to detect and can cause extensive damage if left untreated.

Signs of a slab leak:

• Warm spots on the floor

• Rising water bills despite normal use

• The sound of water running with no fixtures on

• Foundation cracks or floor buckling

Slab leaks are always a plumbing emergency. Learn more in our blog: How to Tell If You Have a Slab Leak.

6. Water Heater Leaks or Inefficiencies

A leaking water heater, especially if tucked away in the garage or a closet, can go unnoticed for weeks. This leads to water waste and potential water damage.

Other issues:

• Sediment buildup can reduce heater efficiency, requiring more water to reach the desired temperature

• A malfunctioning pressure relief valve may cause ongoing drainage

How to check: Inspect around the base of your heater for moisture. If you see rust, corrosion, or puddling, call a plumber.

7. Household Habits and Fixture Upgrades

Sometimes the issue is human error or changing usage patterns. For example:

• House guests using more water than usual

• Extra laundry or dishwashing cycles

• Children developing new bathing routines

Also, older fixtures and appliances use far more water than newer, efficient models.

Examples:

• Pre-1994 toilets can use 3.5+ gallons per flush vs. 1.28 today

• Older washing machines may use 40+ gallons per load vs. 15–20 gallons for high-efficiency models

Consider upgrading to WaterSense-labeled fixtures to save water without sacrificing performance.

8. Broken Pressure Regulator

Your home may have a pressure-reducing valve (PRV) that controls incoming water pressure. If this fails, it could cause abnormally high pressure that leads to:

• Pipe leaks

• Damaged appliances

• Excessive water usage

Signs of failure:

• Sudden high water pressure at faucets

• Banging pipes

• Spikes in your water bill

9. Water Softener Malfunctions

In areas with hard water (like much of Collin County), water softeners are common. But a malfunctioning softener can get stuck in a regeneration cycle, continuously wasting water.

What to check:

• If your softener seems to be running constantly or draining water frequently

• If your bill increased right after softener installation or maintenance

Have a plumber inspect it if you’re unsure whether it's functioning properly.

10. Old or Damaged Plumbing Materials

Older homes in Collin County may still have galvanized steel, copper, or polybutylene piping that has deteriorated over time. These materials are prone to leaks and inefficiencies, especially under pressure.

If your plumbing hasn’t been updated in 20+ years, it may be time to inspect for systemic issues contributing to hidden leaks and water waste.

How to Track Down the Problem

Here’s a quick checklist for narrowing down the issue:

Step 1: Check fixtures and toilets for leaks

Step 2: Inspect your irrigation and outdoor spigots

Step 3: Turn off all water, check the meter, and monitor movement

Step 4: Review household usage changes

Step 5: Call a plumber if the cause remains unclear

Professional leak detection tools can pinpoint issues behind walls, under slabs, or in pipes you can't access.

When to Call Landry Plumbing

If your water bill is unusually high and you can’t find the source, trust the pros. At Landry Plumbing, we help Collin County homeowners:

• Identify and repair hidden leaks

• Detect slab or foundation leaks early

• Replace outdated or inefficient fixtures

• Lower water usage with long-term solutions

We’ll diagnose the issue accurately, fix it efficiently, and help prevent it from happening again.

Don’t Let a High Water Bill Drain Your Wallet

Ignoring a spike in your water bill can lead to larger problems—from structural damage to mold growth and unnecessary utility expenses.

The sooner you act, the more you save.

Call Landry Plumbing today (+1 (469)537-0056) for fast, honest answers and expert service across Collin County.