Can I Use a Hired Digger to Install a Rural Stock Water Trough?

Yes, hiring a digger (excavator) to install a rural stock water trough is absolutely a practical and common approach on New Zealand farms and lifestyle blocks. The excavation work itself — digging trenches for pipework, levelling a pad for the trough, and backfilling — is something most competent homeowners or farmers can do with a hired machine. However, how the trough connects to your water supply determines whether you need a licensed tradesperson involved.

What the Digger Can Help You Do

An excavator makes light work of the tasks that would otherwise take days of hard manual labour on rural properties. A hired digger is ideal for:

• Trenching for poly pipe or other water supply lines from your header tank, bore, or reticulated supply
• Levelling and compacting a stable base pad for the trough (concrete pads are common)
• Digging post holes for any fencing around the trough area
• Backfilling and reinstating the ground once pipework is laid

For most rural stock water setups fed from a private header tank or gravity-fed system on your own property, the excavation and pipe-laying is straightforward DIY work. Poly pipe (commonly 25 mm or 32 mm HDPE) is easy to work with, and fittings are available from rural suppliers and stores like Mitre 10 or Bunnings.

Choosing the Right Excavator Size

For most lifestyle block or farm trough installations, a 1.5 to 3 tonne mini excavator is sufficient. These machines are easy to transport on a standard trailer (check your licence class) and manoeuvrable enough to work around existing fencing and gates. For longer trench runs or harder ground, a 5–8 tonne machine may be more efficient. Talk to your local hire company about ground conditions and trench depth — in NZ, water supply pipes in rural areas are typically buried at least 300–450 mm deep to protect from frost and stock damage, though check with your local council or refer to your regional water supply requirements.

Trench Depth and Pipe Protection

When laying your supply pipe, keep these points in mind:

• Bury pipe deep enough to avoid damage from stock hooves and farm machinery — 450 mm is a good minimum in most rural NZ conditions
• In areas prone to frost (Central Otago, inland Canterbury, high-country Waikato), go deeper or use insulated pipe
• Use warning tape above the pipe in the trench so future diggers know it's there
• Compact backfill in layers to avoid settlement that could stress fittings

Trough Base and Placement

A solid, level base is critical — a wobbly or sunken trough causes leaks and frustration. Options include:

Use your digger bucket to scrape and level the area, then compact the base material before placing the trough. Allow concrete pads to cure fully before loading the trough with water.

Plumbing Connections — Know the Rules

This is where it gets important. In New Zealand, plumbing work is restricted work under the Plumbers, Gasfitters and Drainlayers Act 2006. Whether your trough installation requires a licensed plumber depends on your water source:

• Private water supply (your own bore, tank, or dam, not connected to a reticulated network): Connecting pipework and float valves on a purely private rural system is generally not restricted work, and a competent homeowner can do this themselves. However, always confirm with the Plumbers Gasfitters & Drainlayers Board (PGDB) if you're unsure.
• Reticulated (council or community) water supply: Any connection to a reticulated water supply network must be carried out by a licensed plumber or drainlayer. Doing this work yourself is illegal and could void your supply agreement.
• Backflow prevention: If your trough is connected to any reticulated supply, a backflow prevention device is legally required to protect the network from contamination. This must be installed by a licensed professional.

For Healthy Homes compliance on rental properties with water supply, see Tenancy Services, though this is less commonly relevant for stock water.

Do You Need a Building Consent?

In most cases, installing a stock water trough and associated pipework on a rural property does not require a building consent — it's typically exempt under Schedule 1 of the Building Act 2004. However, if you're constructing a significant concrete structure or a pump shed, consent may be required. Always confirm with your local council before starting, as exemptions can vary. The MBIE Building Performance website has useful guidance on Schedule 1 exemptions.

Safety When Operating a Hired Digger

• Call Before You Dig: Before any excavation, contact Dial Before You Dig (0800 248 344) to identify any underground services — power cables, gas lines, or existing water pipes can be present even on rural properties
• Read the hire company's operator instructions thoroughly before use
• Never work near overhead power lines without contacting your lines company first — refer to WorkSafe NZ guidelines for safe distances
• Wear appropriate PPE: steel-capped boots, hi-vis, and a hard hat when others are nearby
• Ensure the machine is on stable, level ground before operating

When to Call a Professional

Consider hiring a qualified tradesperson if:

• Your water supply connects to a reticulated network (a licensed plumber is legally required)
• You need backflow prevention devices installed
• Ground conditions are difficult — rock, high water table, or unstable soils
• You're unfamiliar with operating excavators safely
• The job involves significant earthworks that could affect drainage or neighbouring properties

A qualified local excavator operator or rural plumber can make the job faster and ensure it's done right. You can find experienced tradespeople in your area at tradedirectory.co.nz.

Sources & Further Reading

• PGDB — Plumbers, Gasfitters & Drainlayers Board
• MBIE Building Performance — Building Consent Exemptions
• WorkSafe NZ — Excavation Safety
• BRANZ — Building Research
• Mitre 10 — Rural & Plumbing Supplies
• Bunnings — Pipe & Fittings