Tree Roots Are Blocking More Adelaide Sewers Than Ever. Is Your Drain Next?

Adelaide's dry spell has had an effect underground that most people never see. In 2024–25, SA Water recorded 5,132 sewer main blockages across its network, up from 4,383 the year before. Tree roots caused 3,275 of them, a big jump from 2,352 in 2023–24.

SA Water puts the rise down to sustained dry conditions, which send thirsty roots looking for moisture inside sewer pipes. It also reports higher blockage rates in foothills and naturally vegetated areas, which describes much of Adelaide's north-east, including Golden Grove.

Those figures cover SA Water's mains, but the same roots are hunting for water in the private drains on your property. Here's why it's happening, the warning signs to watch for, and what you can do before a slow drain turns into a sewage overflow.

1. Why dry weather makes root problems worse

Sewer and stormwater pipes carry water and nutrients, and they're usually warmer and damper than the soil around them. In a dry year, tree roots follow that moisture. Even a hairline crack or a slightly loose joint lets water vapour escape, and fine roots find their way in.

Once inside, roots grow fast. They form a dense mat that catches toilet paper, grease and wipes, and the blockage builds from there. Over time, the roots can widen cracks, shift joints and even break pipes apart.

Golden Grove's reactive clay soil adds to the problem. SA Water explains that clay shrinks and cracks in hot, dry months, then swells with winter rain. That seasonal movement can open up joints in older drainage lines, giving roots an easy way in.

2. Warning signs of tree roots in your drains

Root blockages rarely happen overnight. Most give you plenty of warning if you know what to look for:

• Slow drains in the shower, bath or sinks, especially several fixtures at once
• Gurgling sounds from drains or the toilet after flushing
• Toilets that don't flush properly or rise before slowly draining
• Bad smells around floor wastes or the overflow relief gully outside
• Water or sewage rising out of the overflow relief gully
• Soggy patches or lush green spots in the lawn along the line of your sewer pipe

If you notice two or more of these at once, especially if you have large trees near your drainage line, it's worth getting your drains checked before the problem gets worse.

3. Who is responsible: you or SA Water?

This is one of the most common questions we get. SA Water looks after the sewer mains. Generally, the drainage pipes on your property, up to the point where they connect to SA Water's network, are the property owner's responsibility.

If the blockage is in SA Water's main, SA Water will fix it. If it's in your private drain, you'll need a licensed plumber. A camera inspection is the quickest way to find out where the problem is, so you don't pay for work that isn't yours to fix. If you're unsure, contact SA Water.

4. How we find and fix root problems

Guesswork and digging are expensive. At Grove Plumbing & Gas, we use a CCTV drain camera to see exactly what's happening inside your pipes: where the roots are, how bad the blockage is, and whether the pipe itself is damaged.

From there, the fix depends on what we find:

• High-pressure jetting cuts through roots and flushes the pipe clean. It's the go-to fix for most blocked drains.
• Pipe relining seals cracked or root-damaged pipes from the inside, with no need to dig up your garden or driveway. Learn more about our no-dig pipe relining.
• Pipe repairs or replacement may be needed where a section has collapsed or badly misaligned.

For bigger sewer issues, see our sewer services.

5. How to reduce the risk

You can't stop roots looking for water, but you can make your drains harder targets:

• Find out where your sewer and stormwater lines run before planting new trees, and keep thirsty species well away from them.
• Book a camera inspection if you've bought an older home or have mature trees near your drains.
• Don't ignore early signs. A slow drain is much cheaper to fix than a sewage overflow.
• Keep wipes, fats and oils out of your drains, because they give roots something to catch on.

When did you last have your drains checked? If you've never had a camera through them, now is a good time, before summer dries the soil out again.

For more on what causes blockages, read our guide to the 7 common causes of blocked drains.

Protect your drains before summer

Tree roots are now the leading cause of sewer blockages in South Australia, and dry conditions are making them hungrier. Golden Grove's mature trees and shifting clay soils put local drains at extra risk, but early action makes all the difference.

If your drains are slow, gurgling or smelly, call Grove Plumbing & Gas or book online. We're your local licensed plumbers, and we offer 24/7 emergency support.