You've Hit Something Underground — What to Do Next

If you're reading this on site, something's gone wrong in a post hole and you need to know what to do next. The answer depends on what you've hit. This guide covers the main ones — electrical, gas, water, reticulation, and comms — with the emergency numbers and steps for each.

Every situation is different, but the general rule is the same: stop digging, assess what you're looking at, and call the right people before you do anything else.

Electrical Cables — Stop, Stand Back, Call Now

What to do:

1. Everyone stops work and stands back from the hole immediately. Don't touch the cable, don't try to move it, don't dig around it.
2. If you can safely reach the mains switchboard for the property (without going near the damaged area), switch the power off.
3. Call Western Power's 24-hour emergency line: 13 13 51.
4. If anyone has received an electric shock, call 000 first for an ambulance, then call Western Power.
5. Keep everyone clear of the area until Western Power arrives and confirms it's safe.

Do not attempt to dig around, expose, move, or repair electrical cables yourself. Western Power will send a crew to assess and make the area safe.

If you are operating a machine (excavator, auger, bobcat) that strikes an electrical cable, stay on the machine. Do not step off. The machine's tyres insulate you from the ground. Stepping off creates a path to earth through your body and can be fatal. Stay on the machine, warn others to stay clear, and wait until Western Power confirms the power is isolated before dismounting.

If you lodged a Dial Before You Dig (DBYD) enquiry before starting work and the cable wasn't shown on the plans, that's important for the liability question — hold onto your DBYD reference number. If you didn't lodge an enquiry, you may be fully liable for the repair costs and any associated damage.

Gas Lines — Evacuate, No Sparks, Call ATCO

What to do:

1. Stop digging immediately. Put the machine down, step away.
2. Move everyone away from the area — at least 25 metres if you can smell gas or hear a leak.
3. Do not use your phone near the leak. Walk well away before making any calls.
4. If you can safely reach the gas meter without going near the damaged area, turn it off.
5. Once you're a safe distance away, call ATCO Gas emergency: 13 13 52.
6. If the gas smell is strong, you can hear a significant leak, or anyone feels unwell, call 000 first.

Do not attempt to repair gas lines yourself. ATCO will send a crew to isolate and repair the line.

You will likely be liable for the cost of the repair, the gas loss, emergency response, and relighting affected customers in the area. If you lodged a DBYD enquiry and followed the plans, that works in your favour when it comes to the liability conversation. If you didn't call 1100, that works against you.

Water Mains — Turn Off the Meter, Call Water Corp

What to do:

1. Turn off the water at the meter. The meter is usually at the front property boundary in a green or blue plastic box at ground level. Use a meter key or adjustable wrench to turn the tap off.
2. Assess the damage — is it a small crack, a puncture, or a full break?
3. Call Water Corporation faults and emergencies: 13 13 75 (available 24/7).
4. If the main is fully broken and water is flooding the area, call Water Corp straight away and let them know the urgency.

A cracked or punctured service pipe (the smaller pipe running from the meter to the house) may be repairable by a licensed plumber. A damaged water main in the street or verge is Water Corporation's responsibility to repair, but you'll likely be billed for the costs if you caused the damage.

If the pipe you've hit is clearly old (galvanised steel, green copper, or degraded poly), let the homeowner know — it may have been due for replacement anyway, and a plumber can often sort it out the same day.

Reticulation — The Most Common Hit for Fencers

If you're digging post holes in Perth, this is the one you're most likely to encounter. Retic pipes run through most residential properties and they're usually only 150–300mm below the surface. Along fence lines is one of the most common places to find them.

First steps — every time

1. Turn off the retic controller (usually mounted on the garage wall or near the meter box). If the property runs bore water, turn off the bore pump as well.
2. Assess what you've hit. Is it a main line (larger diameter, higher pressure, feeds the whole system) or a lateral line (smaller pipe running from a valve to individual sprinkler heads)?
3. Check the pipe diameter — this matters when you go to buy fittings.

If it's a quick fix you can handle on site

Most retic damage from post hole digging is a clean break or puncture in a poly pipe. If that's what you're looking at, you can often fix it yourself in 15 minutes.

What you need:

• A poly joiner or coupler that matches the pipe diameter
• Two stainless steel clamps (worm-drive type)
• A sharp knife or pipe cutter

How to work out the pipe size: Wrap a piece of string or a cable tie around the outside of the pipe, mark where it meets, and measure the circumference. Common Perth retic pipe sizes are 13mm, 19mm, and 25mm poly pipe. Take the string to Bunnings or Reece and they'll match the fitting for you. If you carry a few spare joiners on the truck in each size, you won't need to make a trip at all.

The repair:

1. Cut out the damaged section cleanly — straight cuts on both sides, no jagged edges.
2. Push the poly joiner into one end of the pipe, then the other. It helps to warm the pipe ends in hot water or with a heat gun if they're stiff.
3. Slide a clamp over each end and tighten them firmly.
4. Turn the retic back on and check for leaks at the join before you backfill.

If it's a main line or you're not confident with the repair

Let the homeowner know what's happened. If the retic system is well maintained and the garden is clearly looked after, get it sorted quickly — either fix it yourself if you're comfortable, or call in a retic specialist. The homeowner will appreciate you taking it seriously.

If the retic is old, patched together, or half the sprinklers aren't working anyway, the homeowner may not be too concerned about a quick turnaround. Ask them how they'd like to handle it and go from there.

If the homeowner has a retic company they use, get the details and let them deal with it. If they don't, most areas in Perth have mobile retic repair services that can come out same day.

Who pays for the repair?

This depends on the circumstances. If the homeowner told you about the retic layout before you started, or if there were clear markers, and you hit it anyway — that's on you. If nobody mentioned it and there was no way to know, it's a conversation to have with the homeowner. In most cases, a poly joiner and 15 minutes of your time is the easiest way to keep the job moving and the customer happy.

Communications / NBN / Fibre

Communications cables (phone lines, NBN fibre, pay TV) are usually buried in conduit, but not always. Older Telstra copper lines in particular can be direct-buried and surprisingly shallow.

What to do:

1. Stop digging around the area immediately.
2. Do not attempt to repair or rejoin comms cables yourself — especially fibre optic. It requires specialist equipment.
3. For NBN damage, call 1800 687 626 and follow the prompts to report cable damage.
4. For Telstra cable damage, call 13 22 03 and say "report damage" when prompted.
5. You can also report damage to Telstra equipment online at telstra.com.au/forms/report-damage-to-telstra-equipment.

Comms damage is usually the least expensive to repair, but it can take the longest to get a technician out. If the homeowner works from home and you've just cut their internet, let them know straight away so they can make other arrangements while they wait for the repair.

If you're not sure who the cable belongs to, call NBN first — they can usually identify whether it's theirs and redirect you if it's not.

After the Incident — What to Document

Once the immediate situation is handled, take a few minutes to document everything before the repair crew arrives or before you backfill.

1. Take photos of the damage before anyone touches it — the pipe or cable, the hole, the depth, the surrounding area.
2. Note the depth the service was buried at. If it was shallower than the DBYD plans indicated, that's relevant.
3. Note what you were doing when you hit it — hand digging, auger, excavator — and the exact location on the property.
4. Pull up your DBYD reference number if you lodged an enquiry. You'll need it for the utility company and your insurer.
5. Contact your insurer if the damage is significant. Most public liability policies cover accidental damage to underground services, but many have conditions around DBYD compliance.
6. If you didn't call 1100 before starting work, be aware that you may be held fully liable for all repair costs. Asset owners can and do pursue recovery from contractors who didn't follow the DBYD process.

Emergency Numbers

Save these in your phone or print this table and keep it in the truck.

This guide is general information only and was current as at March 2026. Emergency procedures and contact numbers can change — always confirm with the relevant authority. Probuild PVC Fencing is not a utility provider and this is not professional safety advice. In any emergency, call 000.