What counts as a compliant firebreak in WA? Width, height and material rules

The Bush Fires Act 1954 (WA) lets every local government set the technical rules for what a "firebreak" actually is on land inside its district. The defaults are remarkably consistent across the state: a 3-metre-wide break of bare mineral earth or vegetation under 50 mm, sitting inside the property boundary, plus additional clearance around buildings. The variations matter, though. Get the width or material wrong and the break does not legally exist, even if you spent two days slashing it. This guide walks the rules council by council and explains the differences a ranger actually looks for on an inspection.

The four rules every WA firebreak notice covers

A council Firebreak / Fuel Hazard Reduction Notice gazetted under section 33 of the Bush Fires Act 1954 (WA) sets out four technical requirements:

1. Width. Typically 3 m, sometimes 2.1-4 m depending on council.
2. Height of remaining vegetation. Universally 50 mm or less above ground.
3. Location. Inside the boundary, on your side of the fence line.
4. Material. Mineral earth (graded / ploughed bare earth) or slashed grass to height limit. Many notices accept either; some specify mineral earth on larger blocks.

On top of those four rules, larger blocks attract additional internal strategic breaks and buildings inside bushfire-prone areas attract Asset Protection Zones (covered separately - see Asset Protection Zones in WA explained).

Width: 3 metres is the default, but check your council

3 m is the most common perimeter width in WA, but it is a pattern, not a rule - published widths range from about 2 m to 5 m, and some notices set different widths for different land types on the same property. The councils we have checked against their own notices:

Council	Minimum width	Minimum height clearance
City of Kalamunda	3 m	4 m
City of Rockingham	3 m	4 m
City of Swan	3 m	4 m
Shire of Mundaring	3 m	4 m

Your council's own notice is the only figure that counts. Never clear to a neighbouring council's width.

A few notes on width:

• A 3 m break means 3 m measured across at every point, not a 3 m average. Curving the break around a tree and leaving a 1.5 m pinch point fails inspection at the pinch.
• The width is from the edge of remaining vegetation, not from the fence. If your boundary fence has grass growing through it that you cannot cut, your break starts from the inside edge of that grass.
• Larger blocks usually require internal strategic breaks in addition to the perimeter break (see below).

Height: 50 mm of stubble or less

The height rule is the most universal. Across every council notice we have audited, "fuel" within the firebreak must be no taller than 50 mm above ground level. Some notices phrase it as "to ground level" or "to mineral earth", but the practical interpretation is the same: a slashed grass break with stubble around two inches high is compliant; a long-grass strip slashed to ankle height is not.

A few practical points:

• Vehicle clearance is not enough. A grass-trafficable strip you can drive over is not necessarily under 50 mm. Get a contractor with a properly set slasher.
• Mineral earth means earth, not mulch. A ploughed bare strip is mineral earth. A wood-chipped path is fuel and is not a firebreak.
• Tussocks and standing dead vegetation count. If you slashed in October and tussocks have re-grown by January, the break is non-compliant regardless of when the original work was done.

Location: inside the boundary, on your side

Every WA council notice requires the firebreak to sit inside the property boundary, on the landholder's land. This is the rule landholders most often get wrong with the best intentions.

• You cannot clear on your neighbour's side of the fence to satisfy your own notice, even if the neighbour does not mind.
• You cannot clear on the road reserve to satisfy your notice. The road reserve belongs to the council or Main Roads WA.
• The break sits "immediately inside" the boundary in most notices. That phrasing rules out a 3 m break 10 m inside the fence line - that would leave an unprotected fuel strip between your break and the boundary.

If a vegetation corridor on a neighbour's side of the fence makes a compliant break impossible inside your own boundary (a thick row of mature jarrah for example), the resolution is a council variation. Most councils have a written variation process - phone the ranger services team.

Material: slashed grass vs ploughed mineral earth

Both are typically accepted for the perimeter break. The choice is practical, not regulatory:

Method	Use when	Notes
Slashing	Grass paddocks, gentle to moderate terrain, recurring annual job	Cheaper, must be re-slashed if grass regrows above 50 mm
Ploughing / grading	First-time clearance, scrub or heavy fuel, fire-history sites	Creates a more durable break; costs more; can require an APZ contractor with skid steer or tractor; some councils restrict on steep slopes for erosion reasons
Mineral earth grading	High-risk blocks adjacent to bush, large rural blocks	Most durable; the break of choice for council strategic breaks

See firebreak slashing, firebreak ploughing, and fuel-load reduction for service-specific contractor lists.

A separate question is green-waste removal. The slashing creates a tonne of cut grass. Council notices generally do not require haul-away, but if cut grass sits on top of the break it counts as fuel and breaks compliance. Either rake-and-burn under permit, mulch on the spot, or book green-waste removal with the contractor.

Buildings within 50 m of bush: the APZ overlay

If your block has a building within 50 m of bushland (your own or a neighbour's), most council notices add an Asset Protection Zone requirement on top of the perimeter break. The APZ rule is conceptually different from a firebreak:

• A firebreak is a strip along the boundary.
• An APZ is a continuous low-fuel zone around the building, typically 20-100 m radius depending on bushfire hazard level.

The two often overlap on small blocks, but you cannot substitute one for the other. The City of Kalamunda, Shire of Mundaring, Shire of Serpentine-Jarrahdale and Shire of Augusta-Margaret River notices are explicit on the building-protection rule.

The full APZ rules sit under AS 3959 and Planning Bulletin 111. Read Asset Protection Zones in WA explained for the technical detail and how to satisfy APZ and firebreak compliance with a single contractor visit.

Larger blocks: internal strategic breaks

If your block is over 5 hectares (or in some councils, over 5 acres), the notice typically adds internal strategic firebreaks subdividing the block. The Shire of Mundaring, City of Kalamunda and City of Swan notices all specify additional 3 m breaks every 100-300 m on large blocks. The exact spacing and pattern depends on the notice.

This is the area landholders most often under-do. Booking a 1 km perimeter slash on a 20 ha block without the internal grid leaves you exposed if the ranger visits and counts paddock divisions.

Trees over the break: clearance height

A break is not compliant if it has a fuel ladder above it. Council notices vary on the language but the standard rule is clearance to 4 m above the break. That means:

• No overhanging tree limbs lower than 4 m above the cleared strip
• No dead standing trees within the break corridor
• Bark hangers and dead limbs need removal during maintenance

This is the "ladder fuel" concept - low fuel feeds the break, then medium fuel in a sapling layer feeds the ladder, then crowns ignite. Removing the ladder fuel breaks the chain.

Scrub and tree clearing covers the contractor work for limbing and dead-tree removal.

Council variations to watch

The variations that catch people out are not exotic. They are the ordinary ones:

Width is not uniform. Wheatbelt shires commonly sit under 3 m, and some councils go wider. Moving between councils is the classic trap: clearing to the width you used at your last property is not compliance.

Some notices set several widths on one property. A boundary break, an internal break, a break around buildings or haystacks, and an access track can each carry a different figure. If your notice has a table rather than a single number, work through it row by row.

Vertical clearance is a separate requirement. A break can be the right width and still fail because branches overhang it. Where a council states a height, it is usually so a fire appliance can drive the break.

Access tracks and driveways often have their own rule, distinct from the boundary firebreak, and it commonly bites on long rural driveways.

We are not going to list which council does which from memory. Open your council's notice from its page above and read the figures off it.

What a ranger actually checks on inspection

From council ranger services briefings, the routine inspection sequence is:

1. Drive the perimeter. Width measured at random points - typically with a measuring wheel or a 3 m / 4 m stick.
2. Check height. Standing the stick in the grass to see whether the slasher height was set correctly. Anything over 50 mm fails.
3. Check material on the break itself. Cut grass piled in the break = fuel = fail. Leaf litter blown in since slashing = fuel = fail.
4. Check the APZ around buildings. Continuous low fuel for the specified radius - 20 m minimum on most notices, more in higher BAL zones.
5. Check internal strategic breaks on blocks over the size threshold.
6. Photograph any non-compliance for the infringement report.

If the ranger finds non-compliance, you typically get a Direction Notice giving 14 days to rectify. If the work is not done, the council issues an infringement and may execute work-and-recover. See what happens if you miss the firebreak deadline in WA for the escalation pathway and fines.

FAQ

My firebreak was compliant on 1 November but the grass has grown back. Am I in trouble? Yes if a ranger visits and finds the break non-compliant on the day of inspection. The notice requires maintenance through to the maintain-until date, not just installation. Book ongoing maintenance with your contractor for in-season passes.

Can I burn the cleared grass on the break? Not without a permit, and not during the Prohibited Burning Period. Permits are issued by your local Bush Fire Control Officer. Outside the burn season, a small pile burn under permit is the most common disposal method. Otherwise haul away or mulch.

What about firebreaks across a creek line or watercourse? Most council notices have an environmental carve-out for designated watercourses and remnant vegetation. The notice will tell you to consult with the council before clearing in a watercourse buffer. Do not assume the carve-out applies - confirm in writing.

Is a fenced-off horse paddock the same as a firebreak? A grazed paddock is not automatically a firebreak. The 50 mm height rule still applies. Horses keep grass shorter than cattle but not necessarily under 50 mm. Confirm with the ranger; if the paddock is genuinely grazed below height through the danger period, some councils will accept it.

My block is wholly turfed lawn. Do I still need a firebreak? A mowed lawn under 50 mm is technically compliant material. If your entire perimeter strip is maintained lawn, you have satisfied the height rule. Confirm with the ranger that you do not also need internal strategic breaks given block size.

Who is responsible if I rent and the landlord has not cleared? The notice is issued to "the owner or occupier". The council can issue against either or both. Practically, the landlord pays - your lease should say so. If a ranger arrives and the work is not done, you have a tenancy problem and a compliance problem at the same time.

Can a contractor confirm compliance after the work is done? A reputable contractor will measure on completion and tell you whether the break meets the council notice. They are not the legal authority - only a council ranger can sign off. But a good contractor's word is better than a bad ranger's mood.

What to do next

• Look up your address to confirm your council and your width/material requirements
• Read when is firebreak season in WA for the deadline by council
• Read how to choose a firebreak contractor in WA before booking
• Building or buying in a bushfire-prone area? Read Asset Protection Zones in WA explained