The best crew for CBD work is one that locates before it digs, holds a current Sydney Water and Ausgrid-compliant approach, works to AS 5488 for locating classifications, and can show you a clear photo record and a marked-up plan of what was exposed and at what depth.
What makes the best non-destructive excavation in Sydney CBD?
The best crew for CBD work is one that locates before it digs, holds a current Sydney Water and Ausgrid-compliant approach, works to AS 5488 for locating classifications, and can show you a clear photo record and a marked-up plan of what was exposed and at what depth. In a dense CBD, the real differentiator is not the truck. It is whether the operator understands what is under George Street before the vacuum hose comes off the rack, and whether they can work in a night shift window, in a narrow lane, with permits and traffic control sorted.
Non-destructive excavation (also called vacuum excavation, hydro excavation or potholing) uses high-pressure water or air to break up soil and a vacuum to lift it into a spoil tank. Nothing swings, nothing cuts. It is the standard method for proving the exact position of a live service before a pile, a bore, a trench or a pit goes in.
Decide what you actually need first
People search for excavation when what they need is a locate, and the other way around. The two usually go together but they are not the same job.
| What you need | What it involves | When it is the right call |
|---|---|---|
| Utility locate (EM and GPR) | Electromagnetic and ground penetrating radar tracing, marked on the ground and on a plan | Early design, before you commit to a route or pit location |
| Potholing / vacuum excavation | Physically exposing the service to confirm exact depth and position | Before piling, boring, trenching or anywhere a strike is credible |
| Utility survey and mapping | Locate data picked up by survey and delivered as a drawing or model | Design work, as-builts, handing data to a designer or asset owner |
| Concrete scanning | GPR on slabs and walls to find reo, post-tension tendons and conduits | Before coring, cutting or anchoring into structure |
A locate tells you roughly where something is. A pothole tells you exactly. On a CBD job, most clients need both, and the sequence matters: locate, then expose, then record.
What good work looks like on a CBD site
- The locate comes first. A crew that turns up and starts vacuuming on the strength of a dial before you dig plan alone is guessing. Plans in the CBD are routinely out by a metre or more, and abandoned services are often not on them at all.
- Holes are neat and reinstated properly. In the CBD that means saw-cut edges on footpath and road, spoil taken off site, and reinstatement that satisfies the City of Sydney or the road authority. A crew that leaves a ragged hole and cold-mix creates a defect you will be chased for.
- The record is usable. Depth to top of service, service type, size, material, coordinates or offsets from a fixed feature, and a photo with a tape in the shot. If all you get back is a text saying "found it, 900 deep", that is not a record.
- Traffic and pedestrian management is planned, not improvised. CBD footpaths do not tolerate an ad hoc setup. Ask who is providing the TMP and traffic controllers and whether that is in the quote.
- The crew knows when to stop. If a service does not appear where expected, a good operator widens carefully or pulls back and re-locates. A poor one keeps hitting the same hole harder.
The classifications in AS 5488 Classification of Subsurface Utility Information are the plain way to talk about confidence. Quality Level B is a locate from the surface. Quality Level A is a physically exposed and surveyed service. If a job spec asks for QL-A, potholing is not optional, and your report should say which level each utility was captured at. The standard is published by Standards Australia.
What drives the cost
Nobody can quote a CBD potholing job honestly over the phone without a few answers. These are the things that move the number:
- Number and depth of potholes. A 600 mm deep pothole in sand and a 1.8 m pothole through road pavement are different jobs. Depth increases time non-linearly once you are past a metre.
- Surface type. Grass and garden bed are quick. Asphalt, concrete footpath and reinforced slab need saw-cutting and core removal, then reinstatement.
- Access. Can the truck park within hose reach? CBD loading zones, basement height limits, kerb restrictions and pedestrian flow all cost time.
- Work hours. Night shift or weekend work, which many CBD sites require, carries a different rate and often longer setup.
- Traffic control and permits. Road occupancy licences, footpath permits and traffic controllers can be a substantial line item on a CBD job and are sometimes quoted separately.
- Spoil disposal. Contaminated or classified spoil costs more to tip than clean fill, and in older CBD ground that possibility is real.
- Reinstatement standard. Council road reinstatement specs are stricter than a driveway patch.
- Deliverables. A marked ground and a few photos is one thing. Surveyed coordinates, a CAD drawing or a report against AS 5488 is more work and worth asking about up front.
Ask for the quote to state whether it is a day rate or per-hole, what is included in setup and travel, what happens if a service is not found at the expected depth, and who carries the reinstatement.
Questions to ask before you book
- Will you locate with both EM and GPR before excavating, and does the price include that?
- What are your operators' tickets and inductions, and can you work to our site's requirements?
- Do you hold utility-specific accreditations or approvals relevant to working near the assets on this site?
- Who arranges the road occupancy or footpath permit and traffic control, and is it in this price?
- What do I get at the end: marked ground, photos, depths, coordinates, a report?
- What is your process if you find something unexpected, like an unrecorded conduit or asbestos-cement pipe?
- How is spoil handled and disposed of, and is disposal in the quote?
- What insurance do you carry and can I see the certificate of currency?
If a contractor cannot answer 1, 4 and 5 clearly, keep calling.
Red flags
- Quoting a fixed price for unseen CBD ground with no questions asked.
- No mention of locating at all, just "we'll dig where you mark".
- No written record or photos as standard.
- Reluctance to talk about reinstatement or who owns the defect liability period.
- No plan for pedestrians on a footpath job.
Where LCG Locators fits
LCG Locators is one option for this work in Sydney. We do subsurface utility investigation across Sydney metro and NSW: EM and GPR utility locating, utility survey and mapping, non-destructive vacuum excavation, concrete scanning and subsurface reporting for contractors, councils and infrastructure projects. If you want to talk through a CBD site, you can find our services and contact details at lcglocating.com.au, and our accreditation and approvals information sits at aa.lcglocating.com.au.
We do not do architecture, electrical contracting or residential landscaping. If your job needs a licensed electrician to make a connection or a landscaper to rebuild a garden, that is a separate trade, and we are happy to just prove what is under the ground first.
FAQ
Is vacuum excavation safe next to live high voltage and gas?
It is the preferred method precisely because it does not use a cutting edge, but it is not risk-free. Water pressure, nozzle choice and operator technique all matter near cables and polyethylene gas mains, and the asset owner's requirements for working near their plant still apply. Always locate first and treat every unproven service as live.
Do I still need to submit a Before You Dig Australia enquiry if I am hiring a locator?
Yes. The plans from Before You Dig Australia are the starting point and are usually required by the asset owner and your own procedures. They tell you what should be there. Locating and potholing tell you where it actually is.
How long does a CBD pothole take?
For planning, allow that setup, traffic control, saw-cutting, excavation, recording and reinstatement all take time beyond the digging itself. Ground conditions and depth swing it heavily, so ask your contractor for a realistic per-hole allowance for your specific surface and depth rather than assuming a standard rate.