Woollahra's Trees Are Beautiful. And they are also the cause of your drains being blocked.
The fact is: Woollahra is one of the most developed tree canopies in the Eastern Suburbs of Sydney. The NSW Planning Department shows the suburb to be within the 30 to 40 per cent range of canopy cover, and the Woollahra Council has implemented an Urban Forest Strategy that aims to achieve 30 per cent cover of tree canopy throughout the entire municipality by 2050. It will take 25 years, and the council will have to plant 13,410 new trees to reach it. Here, trees are treasured. They're protected. And well deserved is their cooling of streets, cleansing of air, and characterizing of the suburb.
However, deep within all that vegetation, there are those same root systems silently eating away at ageing sewer pipes. In a study published in the journal Landscape and Urban Planning, more than 22,000 sewer pipe segments in 103 Sydney suburbs were analysed and results showed that the abundance of the tree stems was directly proportional to the amount of root blockages. Researchers found that the dataset had 2,942 root-related blockages between 2010 and 2019. Chinese banyan (Ficus microcarpa) was identified as the most important species on the list of predicting the frequency of blockage.
The age of drainage infrastructure in Woollahra adds to the problem. The sewer lines in most of the suburb were laid decades ago, using terracotta or earthenware, in one-metre lengths connected together. Any joint can be of entry. As time passes, the clay cracks, the joints move a bit due to the movement of the soil and the fine root hairs penetrate inside. When they get inside they enlarge, entangle debris and gradually choke the pipe to the point that no water can pass.
This is precisely the case that we encounter in Woollahra. The same can be said of the houses in Moncur Street, Queen Street, Jersey Road and the residential pockets in between Oxford Street and Edgecliff Road, they all have the same features; there are mature trees above, there are clay pipes below the earth, and the drains require professional attention earlier than most owners anticipate.
Blocked Drains in Sydney, What the Data Shows
These aren't made-up numbers. They are based on research by peers, findings of insurance companies, council planning data related to this area of Sydney.
Blockages by tree roots found in 22,192 sewer pipes segments of a 20101919 Sydney study.
The existing tree cover of Woollahra in the NSW Planning Department, which is one of the largest in the Eastern Suburbs.
Average lifespan of clay sewer pipes. A good number of the terrace houses in Woollahra now exceed their design life by far.
Normal length of each section of clay pipe or in other words there is a joint after every one metre which can be exploited by roots.
References: Landscape and Urban Planning (ScienceDirect, 2023); NSW Planning Department canopy data; industry life expectancy of pipes.
The Real Cause of Blocked Drains in Woollahra Homes
All blockages are not equal. Knowing the cause will be the first step in deciding whether a quick clear will resolve the problem or whether there is a greater problem that must be addressed.
Tree Root Intrusion
The most frequent cause of sewer blockages that we observe in Woollahra. Fig, eucalypt and paperbarks are mature trees with roots that penetrate the clay pipe joints. The roots enter the pipe and trap toilet paper, grease and waste until the line is completely clogged. The most common cause of blockages during dry spells is also root intrusion since trees will extend the roots further in search of moisture.
Fat and Grease
Fat used in cooking drained down the kitchen sink does not remain in the liquid state long. When cooled in the pipe they harden on the walls, and tend to narrow the bore. The older terrace kitchens of Woollahra already have pipe diameters modest, making it unsurprising that it will not require a lot of grease accumulation to convert a slow drain into a complete blockage.
Wet Wipes and Foreign Objects
Despite what the packaging says, wet wipes don't break down in sewer systems. They hook up to pipe joins, mix with fats and root matter and create thick clogs that are unexpectedly difficult to move. Sanitary products, hair and cotton buds are all contributors. Unless it is human waste or toilet paper, it should not be in the drain.
Damaged or ruptured Pipes
Old clay and earthenware pipes don't last forever. Sectors may crack after 50-60 years due to settlement of the soil, heavy traffic on top, or pressure of roots. Once a pipe collapses, it does not merely block, it forms a hole in the ground, which becomes increasingly bad. The only sure means of establishing whether a pipe has collapsed is through CCTV inspections.
Stormwater Overload
Woollahra is located over five floodplain catchment areas that have been mapped by the council, Double Bay, Rose Bay, Paddington, Rushcutters Bay and point piers. Ageing stormwater drains have difficulty with volume during heavy rain. Leaves, garden debris and soil drain into grated drains and gully traps. In case the stormwater pipe was already partially clogged, the rain causes it to overflow the side into complete collapse.
Bad Pipe Grade or Layout
In some older Woollahra houses the sewer lines were laid with a very small fall, the slight inclination down the main that keeps the waste flowing. Soil movements, construction activities, and additions of fixtures to the building without changing the drainage disrupt the grade with time. The poor grade lines collect the sediment and waste which would be flushed out by a well graded pipe.
Six Warning Signs You're About to Have a Blocked Drain
Obstructions do not occur during the night. These symptoms typically appear in days or weeks before the drain completely collapses. It is cheaper and less messy to catch them at a young age.
Slow Draining Fixtures
The shower is slower to fill. There is water in the kitchen sink. When you turn on the tap the basin fills. In case of slow draining of one of the fixtures, it is likely to be due to a local obstruction. When several fixtures are slow, then the issue is even further on the main line.
Gurgling in Drains
When the air is blocked partially, the trapped air drives through the water in the blockage making that characteristic gurgling or bubbling noise. It is most evident as you flush the toilet and can hear it in the shower drain, or the other way around.
Bad Smell in Drains or External
The sewage in a partially obstructed pipe begins to ferment. The gases come back up through the drain giving it a smell of rotten eggs, which cannot be ignored. When you sniff it around an outside drain grate, the obstruction would be in the main sewer.
Water Backing up in other Fixtures
You put on the toilet and the shower drain bubbles. You use the washing machine and the laundry floor waste contains water. Once fixtures begin to interact then they have a common drain line which is blocked downstream.
Abnormally Green or Moist Spots in the Garden
An underground sewer pipe that is broken or leaked is in effect fertilising the soil on the surface. When you happen to see a patch of grass that is greener, softer or damper than the rest, especially where a sewer line would be laid, there is a high probability of a broken line of the pipe beneath.
Overfilling External Drain Grates
The primary sewer blockage is commonly revealed through outside drain grates. When the water around an external grate is filled with dirty water or sewage especially one bordering the property, the primary line between the house and the street must be cleared.
Blocked Drains in Woollahra and how we clear and repair them
Various issues require different tools. This is what we apply and when the methods are applicable.
📹 Video CCTV drain inspection
DiagnosticWe send a camera along the line, before we touch anything. The feed lets us see just what is causing the blockage, roots, grease, a collapsed portion, a foreign object, and just where it is. This will exclude guesswork and avoid needless digging. We capture the video and can display to you what we discovered so you know what you are dealing with.
We start with a camera inspection in the heritage properties in Woollahra where excavation is disruptive and expensive. It usually saves humans hundreds of dollars by not spending money on unnecessary work.
💦 High-Pressure Water Jetting
ClearingHigh pressure jet of water is used to cut through the masses of roots, grease and sediment. It is the quickest and most efficient method in clearing a blocked pipe. Jet blasting removes many years of plug compared to mechanical snakes which simply make a hole through the blockage.
In most blocked drains in Woollahra, particularly ones blocked by trees roots or grease, jetting is able to clear the issue within the same day. It can be used on clay, PVC and cast iron pipes provided the operator is an experienced operator.
🔧 Pipe Relining (No-Dig Repair)
Long-Term FixAfter the line has been cleared and the camera shows cracked joints, root entry points, or structural damage, then the most appropriate permanent solution is usually to repair it by pipe relining. The existing pipe is lined with a coating of resin into it which is then cured in the pipe forming a new pipe inside the older one. No joints. No entry points for roots. No excavations of your driveway or yard.
This is important in Woollahra due to the fact that most of the properties have little space outdoors, pavements of heritage, or pre-existing gardens, which would be ruins in case of a conventional excavation. The same outcome can be achieved by relying without the collateral damage.
⛏️ Digging up and Pipe replacement
When NecessaryOther pipes are too deteriorated to be relined. In case a section has completely sunk or moved out of position or contains numerous breaks over a short length, then the damaged section must be excavated and replaced. We replace with modern PVC pipe, which has fewer joints, root intrusion is much more resistant than with clay, and the design life is in decades.
We do not recommend excavation unless there is no viable alternative. It is more intrusive and more costly than relining, but when the pipe is actually in bad shape, it is the means of reestablishing proper drainage in the long-term.
The reason why Clay Pipes in Woollahra are so susceptible.
When most of the houses in Woollahra were constructed, late 1800s to mid 1900s, sewer lines were made of terracotta and earthenware. They were pipes that were laid in short one-metre sections each joined together with a cement or rubber collar. It implies that a 20-metre sewer line contains about 20 joints.
All joints are weak. Pipes move by a small margin as the ground settles over the decades. Joints spread by a few millimetres. That's enough. The roots of trees, even hairy roots, penetrate these micro-gaps, attracted by the moisture and nutrients within the pipe. When ingested, they multiply quickly.
Clay pipes also become brittle with age. The life expectancy is approximately 50-60 years. In a suburb with lots of houses that are more than a hundred years old, much of the old drainage is way beyond its expiration date. That does not imply that we have to replace it all tomorrow, but it does imply that consistent inspection and emptying is what stands between a drain job that can be dealt with and one that is disastrous.
Woollahra Strata Drains and Shared Drainage.
Multi-unit dwellings comprise approximately 76 per cent of the dwellings in Woollahra. That refers to common drainage stacks, common sewer connections, and common stormwater systems. In an apartment building when a drain becomes blocked, it is half the battle to determine who is liable, the individual owner, the owners corporation or Sydney Water.
Generally, pipes within a unit are the owner's responsibility. The pipes which serve the entire building are under the strata scheme. The primary sewer between the boundary trap and the street is the concern of Sydney Water. However, the lines may become blurred, particularly in older buildings where plumbing has been altered throughout the years.
We are accustomed to collaborating with the strata managers of the Eastern Suburbs, and we are familiar with the communication and approval process. In the case of urgent blockages, we clear the drain and then make the paperwork straight afterwards since sewage on the floor of the bathroom in unit 3 is not going to wait till a committee meeting.
Pipe Materials that are present in the Woollahra Properties.
Being aware of the composition of your drains will allow you to see the risks involved, and what can be repaired or not.
| Material | Common In | Normal Lifespan | Root Vulnerability | Repair Choices. |
|---|---|---|---|---|
| Clay / Terracotta | Homes, terraces (pre-1970s) | 50-60 years | High, every 1 metre joints | Relining, replacement of sections, replacement |
| Cast Iron | Mid-century apartment blocks | 50 years -75 years old | Medium, wears away outside with age, relining, replacement of section.t | |
| PVC | Post-1970s constructions, repairs | 50 to 100+ years old | Low, less joints, pliable material | Replacement of part of the section in case of damage |
| Asbestos Cement (AC) | 1940s-1980s buildings | 30-50 years old | Medium, softens, deforms with age | Licensed removal is required; complete replacement |
Lifespan estimates using industry estimates of Australian conditions. Real performance is based on the type of soil, water quality, and the history of the maintenance.
The working of a Blocked Drain Call-Out with us.
Whatever it is, tell us what is going on, slow drains, overflowing grate, bad smell. We will work out what is probably causing it by what you tell us and set a time to meet.
We put a CCTV camera into the line to observe the stop and examine the condition of the pipes. No excavations, no suppositions. You watch the video with us.
We restore flow using the right tool of the job, which is jet blasting, mechanical clearing or both. You receive a quote prior to any action.
In the event we discover broken pipes, root infiltrations, or structural damages, we discuss the choices, relining, partial replacement, or planned maintenance to avoid a recurrence.
Testimonials of our customers
"Our drain in the backyard kept filling up. Plumber Sydney came out, figured it out quickly and cleared it all out. Left the area clean and gave us tips on how to prevent it happening again. "
"Callout was fast, excellent service. Highly recommend, repeat visit, thank you again."
"Telephone assistance on how to resolve an emergency plumbing problem, before coming to get the situation straightened out. Problem was resolved in a few minutes and a follow up call within the following day to confirm that it was operational!"
Frequently Asked Questions
Areas We Service Near Woollahra
We clear blocked drains across Woollahra and all surrounding Eastern Suburbs locations.
Blocked Drain in Woollahra?
Don't let it get worse. A slow drain today is an overflow tomorrow. Call us and we'll get it sorted, properly, on the same day, at a price you've agreed to upfront.
