Essential guide for earthworks in tiger country

22 November 2012

New Zealand’s plantation forests are increasingly grown in tiger country – on steep hills that are often prone to erosion. To harvest those hills, you need highly skilled roading engineers and operators who can construct low-cost, fit-for-purpose, roads, culverts and landings that meet high environmental standards.

To do this, they need a source of reliable information about what works and what doesn’t work in difficult terrain and across a wide range of soil types.

Launching the New Zealand Forest Road Engineering Manual and associated Operators Guide, associate minister for primary industries Nathan Guy complimented the Forest Owners Association for taking the lead. Principal editor Brett Gilmore was praised for putting a huge amount of work into the project.

“The purpose of the Forest Road Engineering Manual is to provide a one-stop shop for information on all aspects of the planning, design, construction and maintenance of unsealed forest roads,” said Mr Guy.

“Road engineering is one of the most technically challenging and expensive parts of forestry. This manual documents best practice and provides all forest owners – large and small – with access to important information.

“This is a very timely update, because many owners who established forests in the 1990s are starting to make plans for developing their infrastructure.”

The annual harvest is forecast to climb to a projected 35 million cubic metres a year from the early 2020s. This could equate to 14,000 km of new harvest access roads required in the next 10 years, at a cost of around a billion dollars.

“A major part of this will come from smaller owners, many of whom may be harvesting for the first time. These owners will be looking for practical guidance on road planning and construction to make existing tracks suitable for heavy vehicle access,” Mr Guy said.

“The guidance on sediment control and erosion will be of particular value to these owners, and links nicely with the National Policy Statement for freshwater with a wider environmental impact view.”

FOA transport committee chair Brian Pritchard said building roads through the bush was a core forestry skill, but in recent years harvesting crews have found themselves working more frequently in steep hill country.

“This has tested the roading and landing making skills of forest owners and contractors at a time when council water quality plans have been paying greater attention to the run-off of silt and other debris.

“But to their great credit, forest owners and contractors have risen to the challenge. They have identified practices that have performed well under storm conditions in very difficult country. They have also identified those practices that don’t perform well.

“The Manual and Operators Guide is the end result of this collaboration. It is also a beginning – an essential starting point for anyone, not just forest owners, contemplating building unsealed access roads in the New Zealand back country.”


The Forest Road Engineering Manual and the associated Operators Guide are available from the Forest Owners Association, PO Box 10 986, Wellington. Tel 04 473 4769. E This email address is being protected from spambots. You need JavaScript enabled to view it.


For more information, please ring Brian Pritchard, Tel 021 900 201 or 06 835 9283