When a big East Coast low is coming down on Sydney, your drainage system is put to the test. It all starts with a small patch of water that just won’t go away, an overflowing pit or water running up to your back door. Suddenly you need to know how to clear an outdoor drain of all that stagnant water before it floods your lounge.

While for many Sydney residents, the first reaction to any plumbing issue is to roll up their sleeves, grab a hose or a spade and get digging, it is essential to understand that there is a thin line between amateur and professional plumbing work. Between using a spade to clear leaves from a drain and digging up the entire garden to access underground pipes, there are specific tasks that require a professional hand. 

Not only are they illegal to attempt on your own but also extremely dangerous. In New South Wales, if you want to clear, repair or excavate any underground drainage pipes, you will need a plumbing licence.

In this article, our team at Emergency Drains has put together helpful information on how to tell what is blocking your outdoor drain, what legal DIY treatments you can try to clear it yourself, and when to call in a professional drainage service.

Why Do Outdoor and Stormwater Drains Get Blocked?

Stormwater drains are intended to channel large amounts of rainwater off your roof and gutters and into the city drainage system. Because they are outside and exposed to the elements, they can easily clog with debris.

Depending on if you are in the leafy North Shore, the established suburbs of the Inner West, or the coastal Eastern Suburbs, the properties in each area will have their own set of challenges based on their individual environment. The leading causes of a blocked stormwater drain in Sydney include:

• Leaves and garden waste: During the autumn, or after a particularly wet summer, a considerable amount of leaves and garden waste can come down the drains and quickly form a thick, almost impenetrable barrier that prevents water from escaping.
• Tree root intrusion: This is perhaps the most damaging type of drain blockage in Sydney. Local trees such as eucalyptus and figs, as well as large bushes, have insatiable roots, which are able to seek out any source of water. The roots then enter the pipes through the cracks and turn into a large mass that blocks the drain completely.
• Dirt, mud and sediment: Heavy rains can wash large amounts of topsoil, sand and mulch into the stormwater inlet during a heavy rainstorm. This can lead to reduced water flow in the pipes due to the build up of dirt and grime inside the underground conduit.
• Collapsed or damaged pipes: Ground movements and shifting clay soils, vehicles driven over ground above the pipes, and the passage of time itself may result in cracked, bent, or completely collapsed pipes.
• Foreign objects: Children’s toys, tennis balls, and hard rubbish can roll down and block drainpipes that have been left unburied.

How to Tell If Your Stormwater Drain Is Actually Blocked

Sometimes a blockage is obvious, but more often than not, it forms quietly and unseen below ground. Recognising the signs can help you prevent costly and inconvenient property damage from occurring.

The main signs of an outdoor drain blockage are:

• Water pooling around the pit: If a torrential downpour ceases and water is still pooling around the pit hours later, there is likely to be an obstruction somewhere underground along the pipe.
• Overflowing gutters and downpipes: Since the downpipes from your roof are connected to the stormwater system, an obstruction in the underground pipes will cause water and debris to erupt from your gutters.
• Soggy lawn: Do you have a particular corner of your lawn or land that seems especially waterlogged? There may be a broken or leaking stormwater drain down below causing water to rise up.
• Gurgling water: Do you hear unusual bubbling or gurgling noises coming from your downpipes or outside drains? This is caused by air trying to escape up through the pipe due to a blockage. There may well be something blocking your drains.
• Persistent blockages: Are you having to clear the same drains repeatedly, month after month? Then there is likely to be a more persistent blockage, such as tree roots growing down from the street above or a collapsed drainpipe down below.

How to Unblock an Outdoor or Stormwater Drain Yourself

If there’s a simple clog, there are a few things you can do as a homeowner to unplug a blocked stormwater drain, legally and safely.

First, put on a pair of heavy-duty waterproof gloves.

1. Stop and assess the area: Look carefully at the location where water is accumulating. Can you see the obstruction that is causing the backup, or is the water collecting in a deeper pit?
2. Remove the grate only if it is safely accessible: If the grate is a standard, lightweight, removable plastic or metal grate, remove it. Do not attempt to pry open heavy, sealed, or municipal grates.
3. Remove visible leaves and debris: Reach into the immediate surface area of the pit and remove any packed leaves, mud, twigs or rubbish. Place this in a bucket rather than leave it on the grass, where it will wash straight back in.
4. Check the pit for surface obstructions: Look down the inlet to see if you can see a blob of goop or a tennis ball lodged in the entrance. If you can see it and get to it, extract it.
5. Flush the drain with water: Using a standard garden hose, insert it into the drain and turn on the water to medium pressure. This should clear any sediment that has accumulated in the pipes.
6. Now follow the progress: If the water starts draining, you have successfully removed the surface obstruction.
7. Stop: If it backs up, you have a deeper obstruction that requires more advanced expertise to deal with and you should stop trying to clear drains yourself.

What You Should NOT Do When a Stormwater Drain Is Blocked

When frustration sets in, homeowners sometimes try to take drastic action to clear an outdoor drain. This often results in serious damage to the pipes, environmental damage, or even legal issues.

The following should be avoided when trying to unclog a stormwater drain:

• Using chemical drain cleaners: Do not use chemical drain cleaners, caustic soda, or acid in an outdoor stormwater drain. Stormwater drains in Sydney are connected to waterways such as Sydney Harbour and the Parramatta River so it is an offence to dump any form of chemical toxin into the system and can cost you heavily in EPA fines.
• Blindly forcing rigid objects into the pipe: Using star pickets, rigid metal rods or other blind plungers will almost certainly crack or break the pipe liner, causing significant problems down the line.
• Digging up underground pipes: Do not loosen underground pipes without determining their location, as you may injure yourself on live cables or gas pipes and aggravate the situation.
• Carrying out regulated draining work: Do not make any attempts to cut or change the direction of the pipes or install new underground drainage pipes.

When Is DIY Drain Work Illegal in NSW?

This is a crucial point that many homeowners overlook. The fact that a stormwater drain is on private property does not necessarily mean that the property owner is legally entitled to carry out any works on it.

Works to plumbing and drains are strictly controlled in New South Wales under the Home Building Act 1989 and the Plumbing and Drainage Act 2011.

According to the rules of the NSW Government, plumbing and drainage work shall only be done by a person holding an appropriate NSW licence, qualified supervisor certificate, or tradesperson certificate.

What is the difference between legal maintenance and illegal draining works?

• Legal Homeowner Maintenance: The removal of leaves from a surface grate, clearing your gutters, or cleaning leaves from a stormwater pit are examples of general property maintenance. You are allowed and encouraged to perform these tasks.
• Illegal Draining Work: The moment you attempt to make a physical repair, modification, disassembly, excavation, or replacement to any underground stormwater conveyance system, you are performing regulated drainage work.

Working on plumbing and draining systems without an appropriate licence is illegal. Moreover, you may be charged with a huge fine if you do any unlicensed plumbing or draining works. In addition, if you attempt to fix the draining system yourself, your insurance company will refuse to cover the damage caused by your amateurish work.

If you have cleared the grate on the surface and it is still not draining, you have reached the level of DIY. It’s time to call a licensed specialist.

When a Blocked Stormwater Drain Needs a Professional

Knowing when to lay down the garden hose and pick up the phone could save you thousands of dollars in property damage. You should seek professional drainage plumber assistance if:

• What to do when the clog remains after all visible trash has been removed: If the grate is clear, then the obstruction is deeper within the pipe system.
• You think it may be tree roots: Tree roots cannot be cleared by a homeowner’s garden hose; they have to be cut out and removed by industrial-grade machinery.
• The pipe is clearly damaged: If you can see that the pit has caved in or that the PVC has broken somewhere, it needs structural restoration by a professional.
• There is more than one drainage point clogged: If your outdoor plumbing, the gutters, and the driveway grates are all backing up at once, there is obviously a blockage in the main storm sewer.
• There is danger of flooding: If water is backing up towards the foundation of your house or into the subfloor and interior of your living space, it is an emergency! Call an emergency plumber right away!

 

For more information on how to make this decision, we recommend that you read our guide on DIY vs professional drain clearing.

How Professionals Find a Blockage

When you call our licensed team at Emergency Drains, we do not do guesswork. We use modern diagnostic tools to find and eliminate the root of the problem safely. Based on the symptoms, a qualified drain specialist will utilise:

• CCTV Drain Inspections: We utilise state-of-the-art cameras to inspect your drains. This lets us see firsthand the condition of your underground pipes without causing any damage. We can determine if your pipe is blocked, broken or even choked with roots.
• High-Pressure Drain Jetting: Rather than use old, harsh methods with metal rods that can puncture the pipe, we offer high-powered hydro-jetting. By using water at up to 5,000 PSI, we can cut right through roots and pulverise hard sediment inside of the pipe while leaving the structure of the pipe intact.
• Root Intrusion Removal: For particularly persistent tree roots that have invaded a pipe, specialist cutting heads can be attached to the jetter to forcibly grind away the root mass and reopen the pipe to its full diameter.
• Pipe Relining: If the camera inspection reveals a cracked or collapsed pipe, we can often avoid excavation work on your garden with our state-of-the-art pipe relining technology. A high-performance epoxy-resin liner is inserted into the existing pipe via the cleanout, where it sets to form a new, seamless pipe within the old one; the new lining comes with a 30-year guarantee!

Who Is Responsible for a Blocked Stormwater Drain in Sydney?

One of the most frequent questions asked by customers is, “Is this my problem to fix, or is it the council’s/Sydney Water’s problem?”

The responsibility to maintain or replace a service pipe depends entirely on where it is.

Private Stormwater Drains (Your Responsibility)

As a homeowner, you are responsible for all private stormwater pipes, pits, and gutters within your property lines and to the point of connection to the main (usually at the kerb) and will need to call a licensed plumber to clear or unblock any internal lines if required.

Public Stormwater Infrastructure (Council or Sydney Water Responsibility)

Once the water has exited your property (usually at the main boundary) and is in the large street main, then it’s out of our hands. Councils are responsible for about 95% of the Sydney region’s stormwater drainage. Sydney water only takes care of a few really big drains, naturalised streams, and some major stormwater catchments.

Drainage Easements

If a local government water drainpipe is running under your block (drainage easement), then the council/water authority is responsible for the maintenance of that particular pipe. Therefore, you cannot build on it or over it.

You can’t build anything over the drain easement. Sometimes it can be difficult to identify where the blockage is; a licensed plumber can organise a CCTV inspection to see where the problem is. If we find the blockage is on the council street main, we can inform you so that you can bring it to the council’s attention.

How Much of the Problem Can You Safely Handle Yourself?

When faced with an overflowing outdoor drain, use this simple decision framework to determine your next steps:

• Visible surface debris on the grate? → Homeowner maintenance is usually fine. Just remove them with gloves.
• Minor blockage just inside the pit? → Again, you may be able to remove it yourself. Unscrew or simply hose it out.
• Persistent blockage that isn’t cleared by a hose? → Call in a professional.
• Do you suspect tree roots or another underground obstruction? → A professional plumber with jetting equipment will be needed.
• Is there damage to the underground pipe that needs repair or replacement? → An appropriately licensed plumber will be required to do this; it’s illegal work for an unlicensed handyman.

How to Prevent Outdoor Drain Blockages

The best way to manage stormwater blockages is to stop them from occurring in the first place.

• Maintain your gutters and downpipes: Blocked gutters will wash a mountain of debris directly down into your stormwater drains, so clean them frequently and thoroughly, particularly in autumn.
• Clear grates before rain: If the weather forecast suggests a big Sydney downpour, take five minutes to stroll your property and remove any leaves that could obstruct your outdoor drain grates.
• Control local flora: Don’t plant aggressive, spreading species (such as ficus or bamboo) near underground pipes.
• Install gutter guards: High-quality mesh can save the day by preventing a significant portion of organic matter from getting into the pipes.
• Book an inspection for recurring issues: If one drain is always clogged, do not attempt to remove the blockage; instead, contact us to conduct an inspection. A camera will discover the issue, and the damaged section will be replaced before it causes an emergency.

DIY vs Professional Drain Clearing: Which Should You Choose?

Use this quick reference table to understand what you can safely handle and when to call us.

 

Situation	Can you handle it yourself?	What to do
Leaves covering an outdoor grate	Usually	Remove visible debris safely with gloves.
Accessible surface debris inside pit	Usually	Clear the obstruction manually or flush with a hose.
Water remains after clearing visible debris	Usually not	Stop. Arrange a professional CCTV drain inspection.
Suspected tree root intrusion	No	Contact a drainage professional for high-pressure jetting.
Collapsed or cracked underground pipe	No	Professional inspection and pipe relining/repair required.
Regulated plumbing/draining work	No	Use an appropriately licensed plumbing professional.

Need Help With a Blocked Stormwater Drain in Sydney?

If your stormwater drain is backing up, or water is pooling on the ground, or you suspect there is a deep-rooted blockage in your system, think about calling us. Do not try to clear your drain by DIY ways that may be illegal or cause water to enter your building. Our licensed and highly trained staff is on standby to help you 24 hours a day all year round.

We carry special CCTV and high-pressure cleaning equipment to clear and fix your pipes according to the law. If the water isn’t draining correctly, we’ll take care of it. Make sure to call us at 1300 524 474 or book online.

Frequently Asked Questions

Can I unblock a stormwater drain myself in NSW?

You can try and remove any foreign objects or leaves that might have gotten stuck on the grate or in the pit that is available for you to see. If it is something that requires digging or adjusting of the pipes or you have to do anything invasive to the piping system, it is best to call in a professional.

Is it illegal to do your own drainage work in NSW?

Yes. According to the law, unlicensed plumbing and draining and other regulated activities are illegal and may be punished by substantial fines. For this reason, the owner of the house cannot perform any cutting, repairing, or other work on the underground water pipes himself.

Who is responsible for a blocked stormwater drain in Sydney?

Homeowners are responsible for all private stormwater pipes on their property up to the point where they join a public pipe. Councils are responsible for approximately 95 per cent of public pipes on streets and Sydney Water is responsible for main drains.

What is the easiest way to unblock an outdoor drain?

The easiest and safest solution to perform on your own is to put on some gloves, lift off the grate (if it is so designed), remove any leaves and mud that may have clogged the inlet, and rinse it off with a hose.

Why does my stormwater drain keep blocking?

If a drain is frequently blocked despite your best efforts to clear it at the surface, there is likely to be a more serious problem underground. The two most common causes in Sydney are tree roots invading the pipe from below and the collapse of a section of the underground pipe.

When should I call a plumber for a blocked stormwater drain?

It is advisable to call a licensed plumber if water backs up around the foundation of your house, suspected root intrusion, multiple drains are backing up simultaneously, or removal of surface obstructions does not clear the clog.

Can tree roots block a stormwater drain?

Yes, tree roots are a big cause of clogged stormwater drains. They penetrate the small holes in the pipes and make large colonies that block the water passage inside the pipe, ultimately leading to damaging the pipe itself.