What lies beneath – the risk in fencing and retaining work

FCANZ

5 days ago

3 min read

Retaining walls and feature fences are a staple of the New Zealand landscape. From boundary fencing on lifestyle blocks through to engineered retaining structures in urban developments, the fencing industry plays a critical role in shaping and supporting our built environment.

What often sits just below that work, however, is just as important – underground infrastructure.

Last year, there were more than 6,000 enquiries submitted through beforeUdig relating specifically to fencing and post driving activity. That’s a significant volume in its own right, but it only represents around 3% of the total enquiries lodged through the service.

In other words, there is a lot of fencing work happening where underground services may not be getting checked – and that’s where the risk starts to build.

Fencing and retaining wall construction might seem low impact compared to large-scale excavation, but in reality, it presents a very real risk to buried assets. Driving posts, augering holes, or digging for retaining wall footings can all put you directly into the path of electricity cables, gas lines, water mains, or fibre networks.

Unlike open trenching, this type of work is often fast-paced and repetitive. Once a crew gets into rhythm, it’s easy for safe digging practices to slip into the background – it only takes one post in the wrong place.

Striking a service doesn’t just mean a bit of inconvenience. Hitting a power cable can result in serious injury or an arc flash event. Damaging a gas line can create an immediate safety hazard for workers and the public. Even a fibre strike can shut down communications to homes, businesses, or critical services – and in many cases, these incidents happen on relatively small jobs.

Retaining walls add another layer of complexity. Depending on the design, excavation can go deeper than expected, especially when stepping foundations or installing drainage behind the wall. That increases the likelihood of encountering services that weren’t initially considered.

So what should fencing contractors be doing?

The fundamentals are simple, but they matter.

Plan before you dig

Lodging a beforeUdig enquiry is quick, and it ensures you receive information from asset owners who have infrastructure in the area.

Prepare the site

Review the plans properly and, if necessary, organise a utility locator to scan and detect for any cables and pipes so you can understand what’s under the ground, and communicate that to your team before work starts.

Pothole to prove the location

If you’re working near known services, physically expose them using safe digging methods before driving posts or using machinery.

Protect what you find

Once services are located, make sure they are clearly marked and not put at risk during the job.

Proceed with care

Conditions change, and not everything underground is perfectly mapped. Use the right tools for the job and stay alert as you work.

The reality is, fencing contractors are often working across multiple sites, sometimes moving quickly between jobs. That makes it even more important to build these steps into your standard process rather than treating them as optional.

The volume of fencing-related enquiries tells us there are plenty of contractors doing the right thing.

But the fact that it only makes up a small percentage of total enquiries suggests there’s still a gap.

Closing that gap is one of the simplest ways to reduce damage, avoid costly delays, and, most importantly, keep people safe.

Whether you’re installing a boundary fence or building a retaining wall, what’s below the surface matters just as much as what you see above it.

Lodge your free beforeUdig enquiry by using the mobile app, on our website www.beforeUdig.co.nz, or by calling us on 0800248344. Download our free Safe Digging Guide for further information on excavating safely near underground utility services.

Written by Phil Cornforth,

General Manager

Published in WIRED issue 81/June 2026 by Fencing Contractors Association NZ

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