At the street, stop 3 of 6

Tree roots and the sewer line

Tree roots in a sewer line usually get in at an old joint or crack, and the first sign is slow or gurgling drains that keep coming back. Columbia Water asks that trees stay out of utility easements for this reason¹. A plumber’s camera settles whether roots are the cause.

Stand at your biggest tree and look along the line between the house and the street.

Updated November 4, 2026, Midlands House Walk

Thick tree root heaving a slab of concrete up beside the trunk — A root breaking a sidewalk in Durham, North Carolina. Roots that can lift concrete deserve a second look if a sewer line runs close by.

Large oak in a front yard with surface roots fanning across grass toward the street — A big oak with surface roots fanning across a front lawn toward the curb, the direction many sewer lines run. AI-generated picture.

Roots heading for the curb

Look for: Stand on the route from your cleanout to the street and note which trees sit close. Surface roots show only part of the spread.
What it tells you: A tree near the line is no proof of trouble. It tells you what to mention to a plumber when drains slow down.

Section of old black fiber pipe with a crumbling, flattened end on red clay — Old fiber sewer pipe with a crushed, flaking end, dug out of red clay. Openings like this give roots a way in.

Old pipe gives roots a way in

Look for: Ask what your line is made of. A plumber’s camera report or an old inspection may say, and an older house is more likely to have older pipe.
What it tells you: Damaged pipe leaves gaps for roots. In Columbia Water’s area the stretch up to the property line is the homeowner’s², so where the break sits matters.

Exposed roots of a live oak spreading through leaf litter to a street curb — Live oak roots spreading through leaf litter to a curb on St. Charles Avenue in New Orleans. Street trees can reach the strip where utilities run.

Trees in the strip by the street

Look for: Check whether the tree stands in the strip by the street, and whether a utility easement crosses your lot. Your plat should show it, or the utility can tell you.
What it tells you: Columbia Water says trees should not be planted in the utility easement, which keeps roots off the pipes and cuts overflows¹. If a tree already stands there, ask the utility before you do anything to it.

Which trees stay away from a septic field?

Clemson names willows, red and silver maples, beeches, birches, elms and poplars as roots to avoid. It suggests less aggressive shrubs no closer than 10 feet, and small less aggressive trees no closer than 20 feet⁵. There is more on septic care.

What if a drain is already backing up?

Roots can wait. Stop using water and go to the first hour of a backup.

Yours to do

Keep a note of which drains slow and when. Every drain at once points past a single sink.
Site new trees well away from the line and out of any easement¹.
Before planting, file with SC811. It is free and covers a job of any size³.
On septic, keep drain openers out of the system⁴.

For a licensed pro

Cutting roots out of a line with a cable or a water jet.
A camera inspection showing where roots enter.
Repairing or replacing the broken stretch once you know whose it is.

Where this comes from

Keep walking (AI picture)Sewage coming up a drain: the first hour