Quarrying on forestry sites

Why forestry quarrying matters

Quarrying is the extraction of rock, gravel, or sand to make roads, tracks, landings, and river crossings at forestry sites. The materials from quarrying help build and maintain safe and durable infrastructure to and within forestry blocks.

However, quarrying alters and removes land at a significant scale. Quarrying activities need to balance operational needs and environmental protection.

Well-planned quarrying on or near the forestry site:

• supports safe and durable access for planting, maintenance, and harvesting
• safely stores overburden, spoil, and stockpiled material
• reduces the transport and environmental costs linked with sourcing materials from further away.

Poorly planned quarrying can lead to:

• unstable slopes
• sediment entering waterways
• expensive clean-up or repair work – especially after storms.

What does forestry quarrying include?

Forestry quarries are usually small and temporary. They can include:

• borrow pits where a small amount of material is “borrowed” for nearby work
• existing quarries on farms that now supply materials for forestry activities
• larger quarry sites supplying material across a wider forest area
• removal of stones, gravel, and sand next to riverbanks
• stockpiling and processing of material on site.

Forestry quarrying is linked with earthworks, roading, and harvesting activities. Where and how you quarry influences drainage, sediment risk, and site stability.

Before you start forestry quarrying

Before you begin, decide if a quarry on your land is the right option.

Estimate how much material you’ll need to build your road network. This includes access to the forest, as well as infrastructure within the block.

Next, look at the geology on your land. Not all types of rock and soil are suitable for road construction. Some materials might be fine to use as is. Others will need crushing and sorting. You might also need to check how much useable material is available.

Compare the cost and effort of establishing your own quarry with sourcing material from an established supplier. In some cases, it might be cheaper and simpler to buy all materials. In others, a mixed approach might work best. You could quarry material from your land for lower road layers, like the sub-base. Then bring in higher-quality aggregate for the road surface.

Planning for forestry quarrying

If you do decide to establish a quarry, there’s a lot to think about. You need to:

• find an experienced quarrying contractor
• provide written notice to the council before you start quarrying
• choose a quarry location away from waterways, unstable ground, and neighbouring properties
• identify aquifers and avoid impacting them
• control how water moves across the site to reduce runoff and erosion
• limit quarry size to reduce landscape impact
• use plantings and other natural features to screen the quarry
• stabilise and restore parts of the quarry as you go.

Forestry quarry erosion and sediment management plan

Quarrying exposes soil and rock, which can wash away in rain events. Large amounts of sediment in waterways decreases water quality and harms environments downstream.

A forestry quarry erosion and sediment management plan sets out how to stabilise land, keep sediment on site, and protect water quality. A good plan will:

• map the proposed quarry layout, including stable areas for overburden, spoil and stockpiled material
• identify erosion risks across the site, looking at slopes, soil types, and nearby waterways
• list the ways to manage runoff, such as drains and sediment traps
• explain how to stabilise exposed areas of the quarry, including reshaping ground and replanting areas.

The plan should be a living document that’s updated as quarrying work progresses. It should detail who is responsible for managing the forestry quarry operation, including inspections and maintenance.

Working with a forestry quarrying contractor

Forestry quarrying needs careful planning, the right machinery, and compliance with the National Environmental Standards for Commercial Forestry (NES-CF).

Quarrying has strict health and safety requirements. This includes the need to engage a competent quarry manager to oversee the work and keep people safe. Because of these responsibilities, you’ll most likely need to hire an experienced contractor.

To find a suitable quarry contractor, you can ask your forest manager or consultant. You can also talk to other landowners who have used a quarrying contractor to manage their quarry.

When choosing a contractor, look at their experience and ask for references. Make sure they explain how they will meet the NES-CF and health and safety obligations. It’s a good idea to get several quotes, so you can compare prices and services.

Risks from forestry quarrying

Quarrying involves excavating large amounts of ground. This can create environmental risks if not well managed.

Common risks include:

• instability of quarry faces or stockpiled material
• erosion and sediment entering waterways
• poor drainage leading to runoff pooling downslope
• visual and landscape impacts if sites are poorly located
• expensive clean-up or repair work – especially after storms
• long term maintenance issues if sites are not restored.

These risks are like those associated with earthworks. They’re influenced by site selection, scale, and timing.

Read more about forestry earthworks

When to do forestry quarrying

Forestry quarrying usually occurs:

• during forest establishment, when infrastructure is first built
• before harvest, when roads and landings need to be constructed or upgraded for heavy traffic
• during harvest, to repair surfaces worn away by heavy traffic or wet weather.

Because pine forests are usually harvested aged 25 to 30 years, you might open a quarry before planting, then reopen it before harvest. A good long-term plan is essential.

You need to:

• plan ahead to have quarry materials ready, so you don’t delay planting or harvesting
• avoid building roads in winter by making sure materials are available before or after this season
• build in contingency time, so you can adjust or pause quarrying during heavy rain or when the ground is saturated.

The NES-CF sets out time requirements for when you must stabilise overburden and deactivated quarries. Your plan needs to include a timeline for stabilising these areas after the project finishes.

Deactivating a forestry quarry

You should stabilise and restore areas of the quarry site as work progresses. Don’t leave clean-up to the end of the project. There are 3 aspects to consider: deposition, stabilisation, and restoration.

Deposition

You should deposit overburden, spoil and other loose material on stable ground. Keeping the deposited material in a small, controlled area makes it easier to manage and restore later.

Make sure material isn’t deposited on steep slopes or areas where rain can carry sediment into waterways.

Stabilisation

Stabilisation should start as soon as possible, not at the end of the quarry project. This includes:

• shaping and compacting the deposited material so water drains away
• roughening the surface of exposed ground to slow down runoff
• using mulch or slash to protect bare soil
• creating simple drains to guide water around and away from the quarry site. 

The main goal is to stop water from pooling or building up speed over bare ground, which causes erosion.

Restoration

Restoration focuses on returning the quarry site to a safe and visually suitable condition. This often means:

• reshaping altered areas, so they blend in with the surrounding land
• replanting vegetation
• making sure old tracks or deposit areas don’t act as channels for erosion. 

By restoring areas as work moves on, you’ll reduce the impact of the quarry and spread effort over time.

Forestry quarrying common terminology

The New Zealand Forest Road Engineering Manual includes some terms you may come across when planning quarrying.

Guidance for earthworks and forestry quarrying

As well as the NZ Forest Road Engineering Manual above, the New Zealand Forest Owners Association provides forest practice guides for earthworks. These cover similar considerations to quarrying.