In New Zealand, locating underground services before any excavation begins is a shared responsibility — but the excavator (whether a contractor or homeowner) carries the primary duty of care. Striking a buried power cable, gas main, or water pipe can be fatal, cause serious damage, and result in significant legal liability. Understanding who does what before the first bucket hits the ground is essential.
The Legal Framework in New Zealand
Under the Health and Safety at Work Act 2015, anyone carrying out work that could harm others has a duty to manage that risk. For excavation, this means identifying and avoiding underground services before digging. WorkSafe NZ sets out clear expectations that excavation work must be planned, and hazards — including buried services — must be identified in advance.
The NZ Building Code and associated standards also require that work near existing infrastructure is carried out safely and without damage to services. If your excavation requires a building consent, your council may ask for evidence that services have been located.
Who Is Responsible — and for What?
Responsibility is shared across several parties:
The Excavator (Contractor or Homeowner)
The person or company doing the digging holds the primary duty of care. Before breaking ground, they must:
- Request service location information from relevant utility companies
- Use a professional cable and pipe locating service where required
- Follow safe digging practices, including hand-digging near known services
- Not assume plans are 100% accurate — buried services can shift or be unrecorded
The Site or Property Owner
The property owner (which may be you as a homeowner) has a responsibility to provide any known information about services on the site. If you've had previous work done, share those records. You also have a duty not to direct a contractor to dig without first ensuring services have been located.
Utility and Network Companies
Electricity, gas, water, telecommunications, and wastewater network operators are required to maintain records of their assets and provide that information when requested. In New Zealand, you can contact individual network operators directly, or use a beforeUdig request (see below) to notify multiple utilities at once.
Using beforeUdig — New Zealand's Free Service Location Tool
beforeUdig (formerly known as Dial Before You Dig) is a free online service that allows you to submit a single request to multiple utility companies, who then respond with plans and information about their underground assets in your area. This is the standard first step before any excavation in New Zealand.
However, plans are a guide only — they show approximate locations and may not reflect every service, especially on older properties. Always treat plans as a starting point, not a guarantee.
Professional Cable and Pipe Locating
For any significant excavation, you should engage a professional underground service locator. These specialists use electromagnetic detection equipment and ground-penetrating radar to physically mark the location of buried cables, pipes, and conduits on the ground surface before digging begins.
This is especially important:
- On older properties where records may be incomplete or inaccurate
- Near roads, footpaths, or boundaries where council or utility services are common
- When digging deeper than 300 mm
- On commercial or subdivision sites
You can find qualified excavation contractors and locating specialists on tradedirectory.co.nz.
Safe Digging Practices
Even after services have been located and marked, safe digging practices must be followed:
| Situation | Recommended Practice |
|---|---|
| Within 300 mm of a marked service | Hand dig only |
| Within 500 mm of a high-pressure gas main | Consult the network operator before digging |
| Unmarked or uncertain areas | Treat as live — hand dig and re-check |
| Striking a service | Stop work immediately, call 111 if gas or power |
Never assume a service is inactive or safe to cut through. Even decommissioned pipes can carry residual pressure or be reactivated.
Restricted Work Near Certain Services
Some work near underground services is legally restricted in New Zealand:
- Electrical work: Any connection to or work on underground electrical cables must be carried out by a registered electrician. Check registration at the Electrical Workers Registration Board (EWRB).
- Gas work: Work on gas pipes and fittings is restricted to licensed gasfitters registered with the Plumbers, Gasfitters and Drainlayers Board (PGDB).
- Plumbing and drainlaying: Connecting to or repairing underground water or wastewater pipes is restricted work under the PGDB.
If your excavation damages any of these services, do not attempt repairs yourself — call the relevant network operator and a licensed tradesperson immediately.
When to Call a Professional
You should always engage a qualified excavation contractor and/or underground service locator if:
- You are digging deeper than 300 mm anywhere on your property
- You are working near the boundary, footpath, or road
- You are unsure of the location of any services
- The project involves machinery such as an excavator or trencher
- You are undertaking work that requires a building consent
For peace of mind and legal protection, hiring an experienced excavation professional is strongly recommended. Find qualified local excavators on tradedirectory.co.nz.
Licensed Building Practitioner (LBP)
