Whether you’re managing a utility upgrade, a civil infrastructure project, or working near protected trees on a development site, the excavation method you choose determines your risk exposure, your compliance position, and your project timeline.
This guide covers everything you need to know: what hydro excavation is, how it works, when it’s the right call (and when it isn’t), what it costs in Melbourne, and why the projects that can’t afford mistakes — from airport runways to occupied schools — choose Precision Hydro Excavations.
What Is Hydro Excavation?
Hydro excavation, also called vacuum excavation or hydrovac, is a non-destructive digging (NDD) method that uses two systems simultaneously:
- A high-pressure water lance that breaks up soil at the dig face
- A high-powered vacuum that extracts the resulting slurry into a sealed debris tank on the truck
The result is that soil is removed with surgical precision and nothing metal ever contacts the ground. No bucket teeth, no auger, no blades. That’s what makes it non-destructive and why it’s the default method on any site where underground services, structures, or root systems are present.
Precision Hydro’s trucks carry debris tanks of 8,000–12,000 litres and operate with hoses reaching 50–100 metres from the truck, meaning the vehicle can stay on the road or hardstand while the operator works deep in a constrained or sensitive area.
How the Process Works
Step 1: Locate
Before a drop of water hits the ground, underground services are identified — via electromagnetic detection, ground-penetrating radar (GPR), or existing as-built drawings. In Victoria, you must also contact Dial Before You Dig (1100) before any excavation work begins. This is non-negotiable on commercial and civil sites.
Step 2: Position
The hydrovac truck positions on hardstand, road, or adjacent clear ground. With hose lengths of 50–100 metres, the truck rarely needs to enter sensitive or constrained areas, a key operational advantage on occupied sites.
Step 3: Excavate
The operator applies pressurised water (typically 1,500–3,000 psi) through a hand lance, breaking up soil. Melbourne’s predominant clay soils, heavy across the western and northern corridors, respond well to pressurised water. Heated water is available for particularly compacted or cold-ground conditions.
Step 4: Extract
The vacuum removes slurry simultaneously into the sealed debris tank. No open spoil on site. No windblown dust. No contamination risk from hydraulic fluid, a real risk with mechanical plant.
Step 5: Dispose
Extracted material is transported in sealed tanks to a licensed disposal or recycling facility. Precision Hydro manages this under ISO 14001-certified environmental procedures on every job.
Why Hydro Excavation?
Mechanical excavation — backhoes, excavators, trenchers — is the right tool for bulk earthmoving in clear ground. On any site where underground services exist, it introduces a risk hydro excavation eliminates: utility strikes.
A utility strike occurs when excavation equipment contacts a buried pipe, cable, or conduit. The consequences:
- Repair costs typically run into the tens of thousands and, for high-pressure gas or high-voltage electrical, hundreds of thousands
- Project shutdowns lasting days to weeks, with flow-on costs across all trades
- Service disruptions to businesses, hospitals, residents, and critical infrastructure
- For high-voltage and gas infrastructure, a direct fatality risk
Under AS 5488-2013 and WorkSafe Victoria obligations, most commercial and civil projects in Victoria require services to be positively located before excavation begins. Positive location means physical exposure, which means NDD. Hydro excavation is the standard method for achieving AS 5488 Quality Level A data: the highest confidence level, requiring direct physical contact and measurement of a service.
Precision Hydro’s underground service locating team works ahead of mechanical plant on live sites, exposing services exactly before any other equipment moves in.
Hydro Excavation vs. Mechanical Excavation
| Hydro Excavation | Mechanical Excavation | |
|---|---|---|
| Best for | Live service environments, constrained or sensitive sites | Bulk earthmoving in clear, open ground |
| Melbourne clay soils |  Highly effective |
Effective — but high strike risk |
| Precision | Very high — operator-controlled at the dig face | Low — bucket width sets minimum excavation size |
| Utility strike risk | Negligible — no metal contact with ground | High — leading cause of underground service damage on Victorian worksites |
| Occupied/sensitive sites | Low footprint, low noise, minimal disruption |
 Not appropriate |
| Compliance (AS 5488) | Achieves Quality Level A service location |
Cannot safely achieve positive location |
| Spoil management | Contained in sealed tank, removed from site | Open spoil — requires separate management |
Where Hydro Excavation Is Specified
- Utility potholing and service exposure on live sites (AS 5488 Quality Level A)
- Trenching within the safe working zone of existing gas, electrical, water, or telecommunications infrastructure
- Tree root zone excavation on development sites (arborist-specified NDD)
- Sensitive sites: schools, hospitals, airports, childcare centres
- Government and council infrastructure projects with explicit NDD requirements
What Does Hydro Excavation Cost in Melbourne?
Precision Hydro charges $195 per hour for a single operator and $265 per hour for a two-operator crew. The right crew configuration depends on the scope and complexity of your project.
Key cost drivers to factor in when budgeting:
- Soil type — hard clay and compacted ground takes longer to break up than sandy or loam soils
- Access constraints — confined or restricted sites slow mobilisation and positioning
- Disposal distance — the further the tip site, the more truck time you’re paying for
- Water source — on-site hydrant access reduces cost; off-site refills add time
- Depth — deeper excavations require more time per cubic metre
- Heated water — adds cost but is necessary for particularly compacted or cold-ground conditions
For a simple utility pothole (1m × 1m to 1.5m depth in medium soil), budget for 1–2 hours. Use Precision Hydro’s NDD estimate calculator for project-specific guidance, or contact the team directly to discuss your scope.
What Sets Precision Hydro Apart
Most hydro excavation operators in Melbourne offer the same core service. What differentiates Precision Hydro is where they’ve been trusted to use it.
Melbourne Airport’s Third Runway Development
Precision Hydro was engaged on works associated with the third runway development at Melbourne Airport, one of Victoria’s most complex and compliance-intensive infrastructure projects. Operating in a live airfield environment required formal contractor induction and strict adherence to airport safety and access protocols. Hydro excavation’s precision — working within centimetres of existing services — was central to its specification here.
Forest Hill School Electrical Conduit Trenching
During school holidays, Precision Hydro completed 40 metres of electrical conduit trenching at a school in Forest Hill. The project was delivered within the holiday window with zero disruption before students returned.
Beveridge Baxter Ecology Tree Root Barrier Installation
Working alongside Baxter Ecology on an urban development site in Beveridge, Precision Hydro performed NDD to install tree root barriers around significant trees with complex, protected root systems. Hydro excavation was the only method capable of working around the root ball without severing fine feeder roots, meeting the project’s ecological compliance requirements without arborist-flagged root damage.
Melbourne Childcare Centre Sand Removal
Sand removal and waterproofing access at an occupied childcare centre in Melbourne — the facility remained operational throughout. Hydro excavation’s low footprint and operator control made it the only appropriate method on a site with that level of occupancy sensitivity.
Beyond excavation, Precision Hydro provides vacuum loading, liquid waste removal, industrial waste management, and CCTV pipeline inspection services that frequently combine on the same project.
The team holds ISO 9001 (Quality Management), ISO 45001 (Occupational Health and Safety), and ISO 14001 (Environmental Management) certification, which was independently audited and recertified in 2025.
Frequently Asked Questions
How much does hydro excavation cost in Melbourne?
Precision Hydro charges $195/hr for a single operator and $265/hr for a two-operator crew. Final cost depends on soil conditions, access, disposal distance, and project duration. Use the NDD estimate calculator for an indicative figure, or contact the team to discuss your project.
What’s the difference between hydro excavation and NDD?
NDD (non-destructive digging) is the category — any excavation method that avoids damaging underground services. Hydro excavation is the most common NDD method, using pressurised water. See the NDD service page for more.
Is hydro excavation required by law in Victoria?
No regulation mandates it by name, but AS 5488-2013 and WorkSafe Victoria obligations effectively require physical service exposure before excavation on most commercial and civil projects, which in practice means NDD. Any excavation deeper than 1.5 metres in Victoria is also classified as high risk and requires protective systems, regardless of excavation method.
How deep can you hydro excavate?
Precision Hydro excavates to a maximum of 5 metres with appropriate safety measures in place, including shoring where required. Any excavation beyond 1.5 metres is classified as high risk under Victorian safety regulations and requires a documented safety plan.
Does hydro excavation work in Melbourne’s clay soils?
Yes, it’s particularly effective in clay. Pressurised water breaks up compacted clay efficiently, and heated water is available for especially dense or cold-ground conditions. Melbourne’s western and northern corridors have some of the heaviest clay profiles in metropolitan Victoria.
Can hydro excavation cut through concrete?
No. Hydro excavation is designed for soil and cannot cut solid concrete. It’s highly effective for safely excavating around concrete-encased utilities or footings, and for removing soil from beneath slabs, but concrete cutting requires separate equipment.
Is it safe near tree roots?
Yes, when operated at appropriate pressures. The lance can be calibrated to lower operating pressures near fine feeder roots, and the operator works manually around the root ball. Victorian arborist specifications on development projects increasingly mandate NDD within tree protection zones.