Tree roots and old sewer laterals: why mid-century homes back up

By Prairie Village Plumbing Company · Published September 30, 2026 · Updated September 30, 2026

Roots are one of the most common causes of main-line backups in older homes. Here's why, who's responsible for the line, and how to decide between cleaning, repair and replacement.

If your basement floor drain gurgles when the washer drains, or the main line clogs every year or two, there’s a good chance the cause is in the pipe between your house and the street: the sewer lateral. In older neighborhoods, the most common culprit is tree roots.

Why older homes are prone to it

Northeast Johnson County is full of mid-century houses. According to the Census Bureau’s 2020–2024 American Community Survey, 57% of Prairie Village’s housing units, 74% of Mission Hills’, 81% of Fairway’s and 77% of Roeland Park’s were built before 1960.

A sewer lateral from that era has been in the ground for 65 years or more. Johnson County Wastewater (JCW), which handles the public sewer in most of these cities, describes the problem plainly: roots that grow within the service lateral may occur from damage in the lateral, like small cracks and breaks from age and soil compaction. The inside of a sewer pipe is warm, moist and full of nutrients, a perfect environment for roots. Once roots get in, they can grow into a mass that slows or blocks the line and causes backups inside the home.

Joints are the usual entry point. Homes of that era were commonly connected with segmented pipe, and every joint is a potential gap as soil shifts over decades.

The warning signs

JCW lists the symptoms customers usually report: slow or slow-flowing drains, minor wet areas around basement floor drains, and gurgling toilets. Other signs:

The main line clogs repeatedly
The drain cable comes back with roots on it
Several fixtures back up at once, or the lowest drain backs up first
A sewage smell in the basement

JCW also draws a useful line: a backup in a drain that’s not on the lowest level is typically an internal clog, while a backup in the main drain or multiple fixtures at the same time may be a sewer backup.

Who’s responsible?

In JCW’s service area, you are. JCW says the pipe that connects your home to its public sanitary sewer main is private property, and homeowners are responsible for the maintenance, repair and replacement of the service line and its connection point on the public main. JCW does not repair or maintain private service lines and connections.

That’s worth knowing before you buy an older home, too. A general home inspection usually doesn’t put a camera in the lateral.

Your options

JCW’s own guidance covers the main options, and we agree with the order.

1. Inspect it. JCW recommends having the lateral inspected by a licensed plumber, and notes that a CCTV camera inspection can determine its current condition and whether repairs are needed. This is the step that tells you whether you have a few roots at one joint or a pipe that’s failing along its length. See sewer camera inspection.

2. Clean it. JCW notes it may be important to schedule regular cleanings of the service lateral, and that cable machines with augers or saws, or high-pressure nozzles, are often used. Cleaning removes the roots but not the cracks they came through, so they grow back. For a line in otherwise decent shape, scheduled cleaning can be a reasonable, lower-cost strategy. See drain cleaning.

3. Repair or replace it. JCW describes two approaches:

Open-cut replacement or repair: digging a trench to replace the damaged section or the whole lateral.
Trenchless lining: a cured-in-place liner is inserted into the existing pipe, essentially creating a new pipe inside the old one.

Which one fits depends on what the camera shows: how much of the line is damaged, whether it has sagged or collapsed, and what’s above it. See sewer line repair.

Permits and costs you should know about

JCW Sewer Repair Permit: required to repair a damaged or collapsed service line. JCW says these permits are free and issues them as quickly as it can because sewer repairs are time-sensitive.
City permits: some cities require their own permits for interior sewer work or anything in the street right-of-way. Fairway, for example, requires a separate permit for work within about 10–12 feet of the curb.
Street Restoration Program: if your lateral runs under a paved public street, JCW’s program can reimburse up to $6,355 per single-family residential property for restoring the street, for homeowners who meet its application requirements.
Before anyone digs: utility locates through Kansas One-Call are required.

What not to do

Don’t pour root-killing or caustic chemicals down a backed-up drain as a first step; they rarely clear a main-line root mass and they make the job hazardous for whoever opens the line.
Don’t connect a sump pump to a floor drain or the sanitary sewer to “help.” JCW prohibits sump pump connections to the sanitary sewer (Resolution WD 92-22) because the extra groundwater can overload the system and back up basements, including your neighbor’s.

The bottom line

If you own a mid-century home in Prairie Village, Mission Hills, Fairway or Roeland Park and your main line has clogged more than once, a camera inspection is the most useful money you can spend on it. It turns a guessing game into a plan.

Call us at (913) 305-5013, or read more about Mission Hills homes and their sewer lines.