Yes, excavators in New Zealand are legally and professionally obligated to notify relevant parties and locate underground services before breaking ground. Failing to do so can result in serious injury, death, costly damage, and significant legal liability. This applies whether you're a professional contractor or a homeowner hiring a digger for a backyard project.
Why Notification Matters
New Zealand's underground infrastructure is extensive — water mains, gas pipes, electrical cables, telecommunications lines, and wastewater pipes can all be buried at varying depths across urban and rural properties. Striking any of these can cause electrocution, gas explosions, flooding, or major service outages affecting entire neighbourhoods. WorkSafe NZ treats unplanned contact with underground services as a serious workplace hazard, and incidents must be reported under the Health and Safety at Work Act 2015.
The "Before U Dig" Process
The primary notification system in New Zealand is Before U Dig (BUD), a free service that connects excavators with utility network operators. Before any digging begins, you (or your contractor) should:
- Submit a Before U Dig enquiry at beforeudig.co.nz, providing the site address and planned work details.
- Receive plans from relevant network operators showing the approximate location of their assets.
- Allow adequate lead time — responses can take several business days, so plan ahead.
- Physically locate and mark services on site using a cable and pipe locator before excavation starts.
Note that BUD plans show approximate locations only. Physical locating with detection equipment is still essential, and hand digging is recommended within the tolerance zone (typically 300–500 mm either side of a marked service, though this varies by operator).
Who Else May Need to Be Notified?
Depending on the nature and location of the work, you may also need to notify:
- Your local council — if the excavation is in a road reserve, footpath, or public land, a corridor access request (CAR) or road opening permit is typically required. Check with your council directly, as requirements vary.
- Your local council building consent team — some excavation work (particularly near foundations or retaining walls) may require a building consent under the NZ Building Code. Schedule 1 of the Building Act lists exemptions, but always confirm with your council before assuming work is exempt.
- Network operators directly — for high-risk work near high-voltage electricity or high-pressure gas mains, some operators require direct notification and may need to have a representative on site.
- Neighbours — not a legal requirement in most cases, but good practice if your excavation could affect shared services or boundary structures.
Legal Obligations and Standards
The Health and Safety at Work Act 2015 places a duty of care on persons conducting a business or undertaking (PCBUs) — including excavation contractors — to manage risks from underground services. WorkSafe NZ provides guidance on safe excavation practices.
The NZ Building Code clauses relevant to excavation include Clause B1 (Structure) and Clause E1 (Surface Water), which govern how excavation can affect ground stability and drainage. Standards such as NZS 3604 apply to timber-framed construction and may be relevant where excavation is part of a building project.
BRANZ also publishes research and guidance on ground conditions and excavation best practice that can be useful for contractors and homeowners alike.
What Homeowners Should Know
If you're hiring an excavator for a home project — a new garden, pool, driveway, or foundation — here's what you should do:
- Ask your contractor whether they have completed a Before U Dig enquiry and physically located services before starting.
- Don't assume that because a service isn't shown on a plan it doesn't exist — older properties in particular may have unregistered or poorly documented services.
- Check with your council about consent requirements before work begins.
- Never dig near marked services without hand digging first to confirm exact depth and position.
| Task | Who Is Responsible |
|---|---|
| Before U Dig enquiry | Contractor or homeowner (before hiring) |
| Physical service location | Licensed contractor / locating specialist |
| Road opening permit | Contractor (applied to council) |
| Building consent (if required) | Property owner / contractor |
| Safe excavation on site | Contractor (PCBU duty of care) |
When to Call a Professional
Excavation near underground services is not a DIY job. Even small diggers can sever a gas main or high-voltage cable in seconds. You should always engage a qualified, experienced excavation contractor for any work near services. A reputable contractor will:
- Handle all Before U Dig notifications as standard practice.
- Use calibrated cable and pipe locating equipment.
- Follow safe digging distances and hand-dig tolerance zones.
- Hold appropriate public liability insurance.
For work involving gas pipes, only a licensed gasfitter registered with the Plumbers, Gasfitters and Drainlayers Board (PGDB) may carry out work on gas infrastructure. For electrical cables, only a registered electrician under the Electrical Workers Registration Board (EWRB) may work on electrical lines. If your excavation exposes or damages either, stop work immediately and call the relevant network operator and emergency services if needed.
You can find qualified local excavation contractors on tradedirectory.co.nz to ensure the job is done safely and to code.
Licensed Building Practitioner (LBP)
