What Happens If a Landscaper Damages Underground Pipes During Earthworks?

Accidentally striking an underground pipe during landscaping earthworks is more common than most homeowners realise — and the consequences can range from a soggy lawn to a serious health or safety hazard. In New Zealand, responsibility for what happens next depends on several factors: who commissioned the work, whether proper checks were done beforehand, and what type of pipe was damaged. Understanding the process can save you significant stress and money.

Why Underground Pipes Are at Risk During Earthworks

New Zealand properties can have a surprising number of services running underground, including stormwater drains, wastewater pipes, water supply lines, gas pipes, telecommunications cables, and electrical conduits. These are often not marked on any single plan, and their depth can vary considerably — especially in older suburbs where records may be incomplete or inaccurate.

Even relatively shallow landscaping work — installing garden edging, planting trees, or building a retaining wall — can reach pipes that sit just 300–500 mm below the surface.

Who Is Responsible When a Pipe Gets Damaged?

Liability generally falls on the party who failed to take reasonable precautions. In most cases, this means:

• The landscaper is responsible if they did not locate services before digging, did not follow safe digging practices, or ignored known risks.
• The homeowner may share responsibility if they provided incorrect information about pipe locations, or if they directed the landscaper to dig in a specific area without disclosing known services.
• Both parties could be involved if there was a breakdown in communication or planning.

A reputable landscaper will always ask you about known services and carry out (or arrange) a service location before breaking ground. If they don't, that's a red flag.

What Should Happen Before Any Digging Starts

The gold standard in New Zealand is to contact Dial Before You Dig (now operating as beforeUdig — check with your local council or lines company for the current process in your region). This free service notifies relevant utility owners, who then provide plans showing the approximate location of their assets.

However, plans are indicative only — they show approximate locations, not exact depths. A professional landscaper should also:

• Use a cable and pipe locator (CAT scanner) on site
• Hand-dig or use vacuum excavation near known services
• Follow WorkSafe NZ guidelines for safe excavation
• Check with your local council for any asset maps they hold

BRANZ also publishes guidance on best practice for construction and earthworks that applies to landscaping projects.

What to Do Immediately If a Pipe Is Struck

If a pipe is damaged during earthworks, act quickly:

1. Stop all digging immediately and assess what has been hit.
2. If it's a gas pipe — evacuate the area, do not use any ignition sources, and call your gas network operator and emergency services (111) straight away. Gas work is restricted work under the Plumbers Gasfitters & Drainlayers Board (PGDB) and must only be repaired by a licensed gasfitter.
3. If it's a water or wastewater pipe — turn off the water supply at the toby if possible and contact a licensed plumber. Repairs to water supply and drainage connections are also restricted work under the PGDB.
4. If it's an electrical conduit or cable — do not touch it. Contact your lines company and an EWRB-registered electrician immediately. Working on electrical infrastructure is strictly restricted.
5. Document everything with photos before any repair work begins.
6. Notify your home insurer as soon as possible.

Costs and Insurance

Repair costs can vary widely depending on the pipe type, depth, and access required. As a rough guide, fixing a cracked stormwater pipe might cost a few hundred dollars, while repairing a pressurised water main or gas line could run into thousands once reinstatement of the ground surface is included.

• The landscaper's public liability insurance should cover accidental damage they cause — always confirm a landscaper holds current public liability cover before work starts.
• Your home and contents insurance may also cover underground service damage, depending on your policy — check with your insurer.
• If the damaged pipe belongs to a council network (e.g., a public stormwater or wastewater main), the council will likely invoice the responsible party for repair and reinstatement.

Building consent may be required for certain reinstatement or repair work — always check with your local council, as requirements vary. Some minor repairs may fall under Schedule 1 exemptions of the Building Act, but confirm this before proceeding.

Preventing the Problem in the First Place

The best outcome is avoiding a strike altogether. Before any landscaping earthworks:

• Ask your landscaper what service location steps they will take — a professional will have a clear answer.
• Share any plans you have for your property, including as-built drawings if available.
• Contact your council to request any service maps for your property.
• Consider vacuum excavation (hydro excavation) near sensitive areas — it's gentler on buried services.
• Check whether your project requires a building consent through MBIE Building Performance, particularly for retaining walls over 1.5 m or significant earthworks.

When to Call a Professional

Any damage to gas, electrical, or pressurised water services must be repaired by a licensed tradesperson — this is non-negotiable under New Zealand law. Do not attempt DIY repairs on these systems. For stormwater or drainage pipes, a licensed drainlayer should assess the damage. You can find qualified local landscapers, plumbers, drainlayers, and other tradespeople on tradedirectory.co.nz.

Sources & Further Reading

• WorkSafe NZ – Excavation Safety
• MBIE Building Performance – Building Consents
• Plumbers Gasfitters & Drainlayers Board
• Electrical Workers Registration Board
• BRANZ – Building Research
• Consumer NZ – Hiring Tradespeople