Fire risks in your forest

What is the risk of fire?

Fire is a minor risk in many areas of New Zealand. Dry, eastern and central areas of the country are most at risk. These areas are more prone to drought, strong winds, high temperatures and severe frosts.

While the forest and its fire environment are the hazard, people are the risk factor. In New Zealand 98% of wildfires are started by people’s activities – it only takes a spark.

A fast-moving rural fire not only destroys forests, it can also extend to pasture, crops and vegetation, homes and livelihoods.

Think of the fire risk before you plant

When you're planning your forest you should consider:

• the local climate and terrain
• vehicle access
• access to water
• fire history of the site
• setback requirements when planting near powerlines and boundaries
• council and legislation requirements
• what species you're planting and how you're going to manage them.

Flammability rates for tree species

There are a range of flammability rates for tree species in New Zealand.

Climate change predictions

It's expected there will be an increase in wildfire risk by 2040 due to hotter, drier, longer summer seasons. We’ve seen fires start earlier in the year (August and September) with dry conditions lasting till May.

Reduce the fire risk in your forest

You can reduce the risk of fire by:

• Establishing firebreaks to stop a fire getting into the forest or to slow its progress. Firebreaks are strips of land that provide a gap in vegetation to slow or stop the progress of fire.
• Maintaining firebreaks by removing or managing vegetation. For example, mowing, grazing or blading it off with a light bulldozer.
• Making sure machinery and equipment is in good order, with suitable fire extinguishers on board and spark arresters if needed. This includes things like chainsaws and motorbikes.
• Considering how and where you use battery power tools, equipment and vehicles.

Wildfire risk management plans

A wildfire risk management plan can help you manage wildfire risks. It includes actions such as:

• managing activities 
• limiting access during high fire risk periods
• coordinating fire control with neighbours and other local forest owners.

The Ministry for Primary Industries has guidelines to help you identify and reduce wildfire risks on your property.

Powerlines

Wildfires linked to powerlines often start, or continue, when auto‑reclosers restore power to lines that have either sparked into nearby vegetation or have been brought down by accidents or high winds.

You must:

• plant within safe setback areas
• make sure there is no branch intrusion in powerline corridors
• notify powerline companies of any powerline or isolator faults, and encroaching vegetation growth.

The Electricity (Hazards from Trees) Regulations 2003 were recently updated by the Ministry of Business, Innovation and Employment.

New Zealand Farm Forestry provides some dated but still relevant information about planting, and the Forest Industry Safety Council (SafeTree) have more information about working safely around powerlines.

Forest management research

There are many different forest management regimes. Research shows the amount, dryness and arrangement of the fuel has a significant impact on the fire hazard. 

How you look after your forest and when you complete forest management work can increase or reduce fire risk. For example, if you thin trees in summer, you increase the risk. The most hazardous period for forestry is within 12 to 18 months following pruning.