How roots affect a water line

Root intrusion is usually discussed with sewer laterals, where roots grow into cracked joints of cast-iron or clay pipe looking for moisture. A water service line is under pressure, so roots do not typically grow inside it. The risk is mechanical: as a large root thickens over years, it can lift, bend or squeeze the pipe, stress old fittings, and eventually crack a joint.

Once a water line leaks near a tree, the extra moisture can draw more root growth toward it. Many Fullerton streets have mature parkway trees close to where meters and service lines sit, so the meter end of the line is a common place for this to happen.

Warning signs near a tree

Repair in place or reroute around the tree

Repair in place

  • Fixes the damaged section where it sits
  • Smaller job if the rest of the line is sound
  • Root pressure may continue to stress the area
  • Digging near roots must be done carefully

New route

  • New line placed away from the root zone
  • Trenchless boring can pass under roots with less damage
  • Old line abandoned in place
  • Larger project, but addresses the cause

Choosing an approach

  • IfA single crack from a root, and the line is otherwise newerThenRepair the section and ask about protecting it, such as a sleeve.
  • IfOld galvanized or copper line running right under a large treeThenConsider replacing it on a new route away from the roots.
  • IfThe tree is a parkway treeThenTalk to the city before any work near its roots.
  • IfRepeated leaks in the same spotThenA reroute usually makes more sense than another repair.

Questions to ask

  1. Is the root actually the cause of this leak?
  2. Can a new line be routed away from the tree?
  3. Would trenchless boring reduce root damage here?
  4. Do I need to check with the city before working near this tree?
  5. How will the line be protected if it stays near the roots?

Common questions

Do roots grow inside water lines like sewer lines?

It is uncommon because the water line is pressurized. The bigger risk is roots pushing on and cracking the pipe from outside.

Can I just remove the root?

Cutting large roots can harm or destabilize a tree, and parkway trees may be the city's responsibility. Ask the city and an arborist before cutting.

Is trenchless better near trees?

Boring a new line under or around the root zone often disturbs fewer roots than an open trench. Whether it fits depends on the site.

General information for Fullerton, not a quote or professional advice. In an emergency, call 911.