Dial Before You Dig: What Perth Homeowners and Contractors Need to Know

If you're digging anything deeper than a garden bed in Perth, you need to call 1100 first. It's a free service, it takes a couple of days, and it could save your life. That's not an exaggeration – hitting a live gas main or electrical cable with a petrol auger is the kind of thing that changes a normal Tuesday into a very bad one.

This guide covers what Dial Before You Dig is, how to use it, what the plans show you, and what to do if something goes wrong. Whether you're a homeowner putting in a fence, a contractor starting a new job, or anyone else planning to break ground in Perth, this is the first step.

What Is Dial Before You Dig?

Dial Before You Dig – now officially called Before You Dig Australia (BYDA) – is a free national referral service. You tell them where you're planning to dig and what kind of work you're doing, and they send you plans showing where underground services are buried on or near your property.

The service has been running since 1987 and actually started right here in Perth, where it was originally called "Perth One Call." It's now used across Australia and covers all the major underground infrastructure networks.

The plans you receive will show the approximate location of:

• Gas mains and service lines
• Electricity cables (both high voltage and standard residential)
• Water mains and connections
• Sewer and wastewater pipes
• Communications – NBN, Telstra, fibre optic, pay TV, and other telecommunications
• Stormwater drainage

The service is completely free for anyone to use. You don't need to be a licensed contractor or a property owner – if you're digging, you can lodge an enquiry.

Is It a Legal Requirement in WA?

Yes. In Western Australia, you have a legal obligation to identify underground services before you start any excavation work. This applies to everyone – homeowners, contractors, builders, landscapers, and anyone else breaking ground.

The obligation sits under the Work Health and Safety Act 2020 (WA), which requires any person conducting work to manage risks to health and safety so far as is reasonably practicable. Digging without checking for underground services is not considered reasonable by any measure.

If you damage underground infrastructure because you didn't check, the consequences can stack up quickly:

• You're liable for the repair costs. Repairing a damaged gas main, water pipe, or fibre optic cable is expensive. Asset owners will send you the bill, and it can run into tens of thousands of dollars depending on what you've hit and how long the service is disrupted.
• Workplace safety penalties apply. Penalties under the WHS Act 2020 range from tens of thousands to several million dollars depending on the severity, with the most serious offences carrying fines of up to $680,000 for individuals and $3.5 million for businesses.
• You could face prosecution. If someone is injured or killed as a result of hitting an underground service – an electrocution, a gas explosion, or similar – the penalties escalate significantly, including the possibility of imprisonment for the most serious offences.
• Your insurance may not cover it. If you can't demonstrate that you took reasonable steps to identify underground hazards before digging, your insurer may refuse the claim.

Lodging a BYDA enquiry is one of the simplest things you can do to demonstrate that you've met your duty of care. It's free, it takes a few minutes, and it creates a documented record that you checked before you started.

How to Use It – Step by Step

The whole process can be done online and it's straightforward. Here's how it works:

1. Go to the BYDA website

Head to 1100.com.au or call 1100 (free from landlines; mobile calls may be charged at a standard rate). The online portal is faster and gives you a record of everything.

2. Create a free account

If it's your first time, you'll need to register. It takes a couple of minutes – just your name, contact details, and the type of work you do (homeowner, contractor, etc.).

3. Submit your enquiry

You'll be asked for:

• The address or location where you're planning to dig
• The type of work you're doing (fencing, landscaping, plumbing, trenching, etc.)
• The planned start date – you need to lodge your enquiry at least two business days before you start digging
• A map of the dig area – the online tool lets you draw the area on a map so asset owners know exactly where to send plans for

4. Receive your plans

Once you submit, BYDA notifies all the relevant asset owners (Water Corporation, Western Power, ATCO Gas, NBN, Telstra, and any others with infrastructure in your area). Each asset owner sends you their plans directly, usually by email, within two business days.

You'll receive multiple sets of plans – one from each asset owner with infrastructure near your site. Keep all of them.

5. Review the plans before you dig

Go through every set of plans you receive. If anything is unclear, contact the asset owner directly – their details will be on the plans. If you're not confident reading the plans yourself, consider getting a certified locator to come to the site and mark the services on the ground for you.

What the Plans Show You

The plans you receive use a standard colour-coding system based on Australian Standard AS 5488. Each type of underground service is shown in a different colour so you can tell at a glance what's running where. Here's the breakdown:

Each set of plans will include a legend, so you don't need to memorise these. But it's worth being familiar with the main ones – especially yellow (gas), orange (electricity), and blue (water) – because those are the services most commonly encountered at residential depths in Perth.

What "tolerance zone" means

The plans show the approximate location of underground services, not the exact position. There's always a margin of error, and this is called the tolerance zone. For standard plans, you should assume the service could be up to 300mm either side of where it's shown on the plan horizontally, and the depth could vary by up to 500mm from what's indicated.

Within the tolerance zone – that is, within 500mm of a marked service – you need to hand-dig or use non-destructive methods only. That means no augers, no excavator buckets, no petrol augers. Hand tools, hydro vacuum excavation (potholing), or water jetting are the accepted methods for exposing services within this zone.

If you need a more precise location, you can hire a DBYD Certified Locator to come to your site and electronically locate the services, then pothole (expose them visually) to confirm their exact position.

What to Do If You Hit Something

Even with the best preparation, things can go wrong. Services aren't always exactly where the plans say they are, and older infrastructure can be poorly documented.

If you hit or damage an underground service:

• Stop work immediately.
• If it's gas – evacuate the area, don't use any electrical equipment or naked flames nearby, and call ATCO Gas emergencies on 13 13 52.
• If it's electricity – move everyone away, don't touch anything that might be live, and call Western Power faults on 13 13 51.
• If it's water – call Water Corporation faults on 13 13 75.
• If it's communications – call the relevant provider (details will be on the plans you received).
• Call 000 if anyone is injured or there's an immediate danger to life.

We've written a more detailed guide for contractors on what to do when you hit underground services during a fencing job, including the full emergency contacts and reporting process. You can read it here: What to Do When You Hit Underground Services.

For Fencing Specifically

Fencing is one of the most common jobs where people hit underground services, and the reason is simple: fence post holes are typically 600mm to 800mm deep. That's deep enough to reach gas lines, water pipes, and communications cables, all of which can be buried at similar depths in residential areas.

Perth's sandy soil adds another layer of risk. Bassendean and Spearwood sands – which cover a large part of the metro area – are loose and drain quickly. Over time, this means underground services can shift from their original position. A gas line that was laid at 500mm depth twenty years ago might now be sitting at 350mm because the soil above it has compacted or been disturbed. A water main that was a metre from your boundary when it was installed might have moved slightly as the sand has settled.

The point is: even if you've lived in the house for years and think you know where everything is, the only way to be sure is to check the plans and, if the services are close to your dig area, get them located on site.

A few things that catch people out with fencing jobs in Perth:

• Services often run along or near boundary lines – which is exactly where fences go. Water and sewer connections, gas service lines, and communications cables frequently run close to property boundaries.
• Corner properties can have services running along two or more boundaries, increasing the chances of encountering something.
• Older suburbs may have services that aren't accurately documented. The further you go back, the less precise the records tend to be.
• Subdivided blocks often have new services running in unexpected locations because they've been routed through what used to be the middle of a larger lot.

For Contractors

If you've been in the trade for a while, you already know all of this. But it's worth having the conversation with your crew – especially apprentices and newer team members who might not have been through the process before.

A few things to build into your pre-job routine:

• Lodge the BYDA enquiry as soon as you've confirmed the job. Plans take up to two business days, so don't leave it until the day before you're due on site. If you do it when you quote, the plans will be waiting by the time you start.
• Keep a copy of the plans on site. If something goes wrong and WorkSafe asks to see your documentation, having the plans on site shows you did your due diligence. Store them digitally on your phone or tablet – BYDA sends everything by email, so it's easy to pull up.
• Brief your crew on the service locations before anyone starts digging. Walk the boundary, show them where the services are marked, and make sure everyone knows the tolerance zones.
• If plans show a service within a metre of a post hole location, hand-dig or pothole that hole first before using the auger. It adds a few minutes to the job, but it's a lot cheaper than repairing a gas main.
• Check the plans are still valid. If the job gets delayed and your plans expire (most are valid for 28 days), lodge a new enquiry before you start. Infrastructure gets added and moved – the plans you got two months ago might not reflect what's in the ground today.

It takes about two minutes to lodge a BYDA enquiry online. It's free. It protects you legally, it protects your crew physically, and it keeps your insurance valid. There's no reason not to do it on every job.

Useful Links and Contacts

This guide is general information only and was current as at March 2026. Requirements can change – always lodge your own BYDA enquiry and check the latest guidelines at byda.com.au before you start any excavation work. Probuild PVC Fencing is not a regulatory authority and this does not constitute legal advice.