Rural Driveways and Culverts: Section 138 Approvals in NSW

If you own acreage in NSW, the driveway is often the part of the property you think about last — right up until a wet winter turns it into a bog, or council knocks back your building plans because the access does not meet their standards. Building or upgrading a rural driveway is not just an earthworks job. Where the driveway crosses the road reserve, it is a piece of public road infrastructure, and it needs formal approval before you touch it.

This guide explains section 138 of the Roads Act 1993 (NSW), when you need it, how it interacts with your DA or CDC, and the engineering fundamentals of rural access design — grades, sight distance, culverts, table drains and bushfire access. It is written for rural land owners, builders and developers working anywhere in NSW, from the Hawkesbury fringe to the far west.

What is a section 138 approval?

Under section 138 of the Roads Act 1993 (NSW), you must obtain consent from the roads authority before carrying out any works or erecting any structure in, on or over a public road. The “public road” includes the entire road reserve — not just the sealed pavement, but the verge, the table drain and everything between your front boundary and the carriageway.

For rural properties, the works that most commonly trigger a section 138 approval include:

• Building or upgrading a driveway or vehicle crossing between your property boundary and the road.
• Installing a culvert or pipe under the access where it crosses the table drain.
• Digging or trenching in the road reserve — for example, to bring in power, water or communications services.
• Connecting stormwater from your property to the road drainage system.

If your plans involve any of these, assume a section 138 consent is required and build it into your programme. Councils take unauthorised works in the road reserve seriously, and an unapproved crossing can hold up an occupation certificate or become a costly rectification order later.

Who is the roads authority?

For unclassified local roads — which covers the vast majority of rural roads in NSW — the local council is the roads authority, and the section 138 application goes to council. For classified roads such as highways and main roads, Transport for NSW concurrence or approval may also be required, which adds time and usually tighter design requirements for sight distance and turning movements. If your frontage is on a classified road, raise it with your engineer early, because the access location itself may need to change.

How section 138 fits with your DA or CDC

A common misconception is that development consent covers everything. It does not. A section 138 approval is a separate approval from your development application (DA) or complying development certificate (CDC), issued under different legislation. Getting a DA approved does not authorise you to build the crossing — it simply approves the development that the crossing serves.

The typical sequencing works like this:

• With a DA: apply for the section 138 consent after the DA is approved, so the driveway and culvert design is consistent with the approved plans and any conditions of consent. Many DAs include a condition requiring the section 138 approval before a construction certificate or before works commence in the road reserve.
• With a CDC: councils often require the section 138 consent before or alongside the CDC, because the private certifier issuing the CDC cannot approve works on public land. Check the specific council’s requirements — practice varies.

Either way, the crossing design usually needs to be prepared or checked by a civil engineer, showing levels, grades, the culvert size and class, headwall details and how the table drain is maintained through the works.

Designing a rural driveway that actually works

Council approval is the minimum bar. A good rural access also needs to work every day, in all weather, for the life of the property. These are the design fundamentals we look at on every acreage job.

Grades and vertical alignment

Rural blocks are rarely flat, and the temptation is to run the driveway straight up the hill. Steep grades cause scouring on gravel surfaces, traction problems in the wet, and grief for trucks during construction and for fire appliances afterwards. A well-designed alignment balances length against grade, uses cut and fill sensibly, and transitions smoothly at the road so vehicles do not scrape or bottom out at the crossing. The vertical geometry at the entrance also matters for drainage — the driveway should shed water off its surface rather than channelling it down the wheel paths.

Sight distance at the entrance

The single most important safety element of a rural access is sight distance: can a driver pulling out of your property see far enough along the road, in both directions, to enter safely, and can approaching traffic see your entrance in time to react? On roads with higher speeds, crests, curves or vegetation, the obvious entry point is often not the safe one. Councils assess sight distance as part of the section 138 application, and on classified roads Transport for NSW will scrutinise it closely. Sorting this out at concept stage is far cheaper than redesigning after a refusal.

All-weather surface: gravel or sealed

Most rural driveways are gravel, and a properly built gravel pavement — shaped with crossfall, compacted in layers, with drainage that takes water away from the surface — will serve well for years. Sealing makes sense on steep sections where gravel scours, at the road interface where councils often require a sealed apron, and near the house to control dust. Whatever the surface, “all-weather” is the test: you, your visitors and emergency services need to get in and out after a week of rain, not just in the dry.

Passing and turning provision

On long rural driveways, think about what happens when two vehicles meet, and how a delivery truck, horse float or fire tanker turns around at the house end. Passing bays at intervals and a practical turning area near the dwelling cost little during construction and are painful to retrofit. On bush fire prone land, some of this is not optional — more on that below.

Culverts: the make-or-break element

Where your driveway crosses the table drain — or a gully or creek further into the property — a culvert carries the water underneath. This is where most rural accesses fail, and almost always for the same reason: the pipe is too small.

Sizing for the real flow

A culvert must pass the design storm flow for the catchment draining to it. For a table drain crossing, that catchment is the road drainage system upstream of your access; for a creek crossing, it can be hundreds of hectares of paddock and bushland. Sizing is a hydrologic and hydraulic calculation, not a guess. Many councils specify minimum pipe diameters for crossings regardless of calculated flow — the exact figure varies by council — because small pipes block with debris even when the hydraulics say they are adequate. Your engineer should check both the council’s specification and the actual catchment.

Pipe or box culvert?

Round pipes suit most table drain crossings: they are cheap, readily available and easy to install. Where flows are larger or cover over the pipe is limited — common on flat creek crossings where you cannot raise the driveway — box culverts provide more waterway area for less height. Multi-cell arrangements spread the flow where a single large unit will not fit under the driveway profile.

Headwalls and scour protection

A bare pipe end poked into the drain is an invitation for the embankment to unravel. Headwalls and wingwalls retain the driveway fill, direct flow into and out of the culvert, and protect the pipe ends from damage. At the outlet, water leaves the pipe faster than it entered the drain, so scour protection — typically rock — dissipates that energy before it erodes the drain invert or your neighbour’s frontage.

Keep the table drain flowing

The table drain exists to drain the road pavement. Your crossing must let that water continue past your access, not dam it. A culvert set too high, or a driveway built as a solid bund across the drain, ponds water against the road pavement, softens the subgrade and shortens the road’s life — which is precisely why councils police these crossings through section 138. The culvert invert should match the drain profile, and the drain should be reinstated on both sides of the works.

Causeways versus culverts

On larger creek crossings within the property, a concrete causeway that lets flood flows pass over the top is sometimes more sensible than an enormous culvert — particularly where floods are infrequent, short and shallow. The trade-off is access: a causeway is impassable during a flow event, which matters if it is your only way in and out, and matters even more for bushfire egress. Culvert crossings with the driveway above flood level cost more but keep you connected. This is a genuine design decision that depends on the catchment, the crossing’s role and your budget.

Why undersized culverts fail

When a culvert cannot pass the flow, water backs up behind the driveway embankment until it overtops. Flow over an unprotected gravel embankment strips it in minutes — first the shoulder, then the fill around the pipe, and the crossing washes out entirely, often taking the pipe with it. You then pay for the crossing twice, plus the emergency access problem in between. Spending a little more on the right size pipe, proper compaction around it and protected overflow paths is the cheapest insurance on a rural property.

Bushfire access requirements

If your land is mapped as bush fire prone — as a large share of rural NSW is — Planning for Bush Fire Protection 2019 sets property access standards that apply to longer rural driveways serving new development. These address matters such as trafficability for firefighting appliances, passing and turning provision, and the driveway’s ability to function as a safe route in and out during a fire event. If a creek crossing on your access has load or width constraints, that becomes a bushfire compliance issue as well as a structural one. Where bushfire requirements apply, design the driveway to satisfy both council’s access specification and the bushfire standards from the outset, rather than treating them as separate exercises.

Whose job is maintenance?

A point that surprises many owners: even though the crossing sits in the public road reserve, vehicle crossings are generally the property owner’s responsibility to maintain. If the culvert blocks, the gravel ravels or the headwall cracks, the repair bill is typically yours, not council’s. That is another reason to build it properly once — a well-constructed crossing with the right pipe, compacted backfill and protected ends needs little more than keeping the pipe ends clear of debris.

Where vehicle access is tight, our group transport specialists at Sweptpaths prepare the swept-path assessments councils ask for.

Frequently asked questions

Do I need council approval just to put a pipe in the table drain?

Yes. The table drain is part of the public road, so installing a culvert or building a crossing over it requires section 138 consent from the roads authority — usually your local council — even if no other development approval is involved.

Is a section 138 approval part of my DA?

No. It is a separate approval under the Roads Act 1993. With a DA, you would typically apply for the section 138 consent after the DA is approved so the designs match; with a CDC, many councils want the section 138 consent before or alongside the certificate. Confirm the sequence with your council.

What size culvert do I need for my driveway?

It depends on the catchment draining to the crossing and your council’s specification. Many councils set minimum pipe diameters for rural crossings, and the figure varies between councils. A civil engineer can size the culvert for the actual flows and check it against the council standard — the minimum is not always enough on larger catchments.

My driveway is long and the land is bush fire prone. Does that change the design?

Very likely. Planning for Bush Fire Protection 2019 sets access standards for rural driveways on bush fire prone land, covering matters like trafficability for fire appliances and passing and turning provision. These requirements should be built into the driveway design from the start.

Get your rural access designed and approved

Contrive Consultants is a civil and stormwater engineering consultancy based in Rouse Hill, working with rural land owners, builders and developers across NSW — including regional areas via remote delivery. We design rural driveways and culvert crossings, prepare section 138 application documentation, and coordinate with councils and certifiers so your access is approved and built right the first time. Explore our civil and stormwater engineering services, or get in touch through our contact page, call +61 497 848 111 or email info@contriveconsultants.com.au to discuss your property.