A Homeowner's Guide to Preventing Sewer Backups (2025)

What Is a Sewer Backup?

A sewer backup happens when wastewater from your home (like from toilets, sinks, and showers) can’t drain and flows back inside. This usually occurs through the lowest drains, such as basement floor drains. The result can be thousands of dollars in damage and serious health risks from exposure to raw sewage.

According to public works data and Civil Engineering Research Foundation reports, sewer backups are increasing 3% each year due to aging infrastructure and storm overload. Climate change and increased rainfall are making backflow incidents more frequent, especially in cities with outdated drainage and flood control systems.

A backup may affect one home or spread across multiple homes and businesses. Often, a backup occurs suddenly, especially during storms or after dry spells when debris and silt block lines.

What Causes Sewer Backups?

1. Old Sewer Systems

The U.S. has hundreds of thousands of miles of sewer lines, many more than 30 years old. These aging systems deteriorate over time. Cracks form and flow slows, particularly when not inspected annually. A failing sewer pipe can collapse without warning.

2. Tree Roots

Roots can sneak into cracks in pipes and block them. This is a common cause of backups and is usually the homeowner’s job to fix. Even small roots can grow quickly and become a major problem.

3. Clogged City Pipes

Roots from nearby trees or shrubs can infiltrate even small pipe cracks and clog the line. These blockages are a common cause of sewer backup. Once inside, roots expand and choke the flow.

4. Combined Sewer Systems

In older cities, storm water and sewage share the same pipes. During rainstorms, the extra volume can force backflow into homes. These types of sewer backups are preventable with upgraded infrastructure.

5. Grease, Wipes, and Fats

Never pour grease or fat down your drain. It cools and sticks to the walls of your pipe. Over time, it combines with other debris and creates stubborn blockages. Wipes and feminine products also cause clogs and should always go in the trash.

6. Heavy Rain, Silt, and Debris

Storms can push large volumes of water, silt, and debris into the system, triggering a backup. When flood control systems are overwhelmed, backflow into basements becomes inevitable.

7. Illegal or Poor Drain Connections

French drains, gutters, or a sump pump discharging into your sanitary sewer is illegal in most cities. These practices overload the system and increase your risk of a sewer backup.

Why Sewer Backups Are So Bad for Homeowners

1. Health Risks: Raw sewage can back into your home, spreading bacteria and viruses.

2. Cost: Cleanup from a backup may range from $5,000 to $50,000, especially when flooring, furniture, and drywall are affected.

3. Insurance Gaps: Many policies do not cover sewer backup unless you purchase a special rider.

4. Emotional Toll: Recovering from a backup is stressful. It may take weeks to clean, repair, and replace what was lost.
   

How to Prevent A Sewer Backup

1. Use a Backwater Valve

Also called a backflow valve, this simple device prevents wastewater from flowing back into your home. A licensed plumber can install one on your main line. It may be required in flood-prone areas.

2. Get Regular Pipe Checks

Check valves help manage backflow in sump discharge lines and are often installed in basement systems. These one-way valves protect your property during surges in the sewer system. 

Don’t flush anything except toilet paper. Avoid sending wipes, hose water runoff, or debris down the line. These materials cause blockages and increase the risk of backflow.

3. Follow EPA SepticSmart Tips

If you’re on a septic system, follow EPA’s SepticSmart program. Don’t park or build over the tank or drain field. Pump the tank every 3 to 5 years to prevent overflows. Never flush anything but toilet paper—not wipes, tampons, paper towels, or medications, which can clog or damage your system.

4. Dispose of Grease and Fat Properly

Never pour grease or cooking fat down the sink. Let it cool, collect it in a can or bucket, and throw it out. It doesn’t just damage your pipes—it clogs municipal lines too.

5. Install a Sump Pump

A sump pump doesn’t prevent sewer backups, but it helps manage stormwater and groundwater that can flood your basement. Make sure it discharges water away from your home’s foundation and test it monthly. Consider adding a battery backup in case of power outages.

6. Disconnect Gutters and Drains

Gutters and foundation drains should never empty into the sanitary sewer line. Doing so can overload the system and trigger backups. Make sure downspouts, gutters, and French drains discharge water away from your house and not into the sewer system. Never connect these control systems to your sanitary sewer.

The Best Way to Stay Safe: Real-Time Sewer Alerts

Even with good habits, a sewer backup can still happen. That’s where SewerAlarm makes a difference.

SewerAlarm is a smart, WiFi-connected sensor that monitors for backflow in your drain line. When wastewater starts rising, it sends real-time alerts by text, email, or through your home alarm.

• Installed by a licensed plumber in under an hour

• Loud alarms and smart alerts give you time to act

• Helps prevent expensive damage from backflow

• Smart home compatible for full-system integration

It’s the only early-warning device for backflow and sewer backups available to homeowners. If your goal is to prevent sewage from invading your home, this is the tool you need.

Learn more at SewerAlarm.com.

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What to Do If You Experience a Backup

If you notice a backup starting, here’s what to do:

1. Stop using water—turn off faucets, showers, and toilets.

2. Shut off power if water nears electrical outlets.

3. Call a licensed plumber immediately.

4. Document damage with photos and notes.

5. Avoid contact with sewage—it poses serious health risks.

6. Start an insurance claim right away.
   

In Summary for Homeowners and Landlords

Sewer backups are happening more often and cost more than most people think. They’re messy, expensive, and sometimes dangerous. Prevention helps, but technology like SewerAlarm can give you an edge.

Don’t wait for a disaster. Protect your property today with smart, simple steps.

Sources:

• EPA SepticSmart – epa.gov/septic

• American Society of Civil Engineers – infrastructurereportcard.org

• CDC – cdc.gov

• National Association of Insurance Commissioners – naic.org

• Insurance Information Institute – iii.org

• City of Papillion Sewer Backup Guide – papillion.org