Draft BPAM WA Standard Section 7 and associated Appendix:
7. IDENTIFYING THE BUSHFIRE-PRONE AREA
7.1 Intent
The purpose of the State-wide Bushfire-Prone Area Map (State Map) being a binary
methodology (designation being either bushfire-prone area or not applicable),
identifies bushfire prone vegetation with the intent to inform the application of AS
3959-2009 Construction of building in bushfire prone areas (AS3959) in accordance
with (draft) State Planning Policy 3.7: Planning for Bushfire Risk Management
(SPP3.7).
Developments within bushfire-prone areas and buffers will be required to undergo a
Bushfire Attack Level (BAL) assessment by an accredited BAL 1 Assessor (using the
simplified method within AS3959). The State Map does not measure bushfire fuels or
bushfire risk. Bushfire risk and subsequent treatments and controls will be
determined through the application of AS/NZS ISO 31000 Risk management Principles and guidelines (ISO 31000).
7.2 Identifying the Bushfire-Prone Area
The bushfire-prone vegetation and the bushfire-prone buffer collective is a dataset
and used to create the bushfire-prone areas identified on the State Map. These
areas will be used for the purposes of applying SPP3.7, the (draft) Planning for
Bushfire Risk Management Guidelines and AS3959.
In most cases, desktop assessment and utilising existing local knowledge is an
adequate process for verifying the bushfire-prone vegetation data. A field
assessment would be appropriate where data or local knowledge is not sufficient to
make a determination.
The methodology for generating the bushfire-prone vegetation and bushfire-prone
buffer datasets is identified below.
7.3 Assessing Bushfire-Prone Vegetation
As previously mentioned the bushfire-prone vegetation is classified in accordance
with the AS3959. It was initially derived through existing datasets, and will be further
improved by a range of measures including local level verification, aerial
photography interpretation and some field validation. The vegetation identification
process includes the following vegetation communities 1 (refer to Appendix 2 –
Vegetation Key):
a.
b.
c.
d.
e.
f.
1
Forest
Woodland
Shrubland
Scrub
Mallee/Mulga
Rainforest
AS3959-2009: Construction of buildings in bushfire-prone areas, Standards Australia, 2009, p. 15-16.
g. Grassland
In addition to the AS3959, other vegetation for consideration includes:
h.
i.
j.
k.
Bare areas
Isolated areas
Wetlands
Managed Grasslands
7.3.1 Inclusions Areas
Land containing at least one of the bushfire-prone vegetation communities
identified in the Vegetation Key – Appendix 2 shall be identified as bushfire-prone
vegetation in accordance with the following criteria:
1. All parcels of the above vegetation that are greater than 1 hectare in size shall
be identified as bushfire-prone vegetation.
2. Single areas of bushfire-prone vegetation that are between 0.25 and 1
hectare in area and are within 100 metres of other parcels of vegetation in the
identified communities greater than 1 hectare in size shall also be identified as
bushfire-prone vegetation.
7.3.2 Exclusions Areas
Land containing the above vegetation communities shall NOT be identified as
bushfire-prone vegetation in accordance with the following criteria:
1. Single areas of vegetation less than 1 hectare in area and not within 100
metres of other parcels of vegetation shall be omitted.
2. Multiple areas of vegetation less than 0.25 hectare in area and not within
20 metres of each other shall be omitted.
3. Strips of vegetation less than 20 metres in width regardless of length and not
within 20 metres of each other or other areas of bushfire-prone vegetation
shall be omitted.
In addition to the above criteria, any areas of managed grassland that are
maintained in a minimal fuel condition in perpetuity, or that are free from vegetation,
are not to be identified as bushfire-prone vegetation and will not be shown in the
bushfire-prone area dataset. This will be monitored by the respective local
government.
7.3.3 Grasslands
AS3959 currently includes building construction requirements for grasslands where
the vegetation is not managed below a height of 100mm (i.e. grassland that is
considered ‘unmanaged’ or ‘natural/undisturbed’). At this point in time it is not
possible to accurately map areas of unmanaged grasslands due to limitations with
the vegetation datasets currently available. However, there is a need to ensure that
buildings in close proximity to such areas are constructed appropriately.
To ensure that unmanaged grasslands are appropriately taken into consideration,
DFES and local governments are strongly encouraged to advise OBRM of areas of
unmanaged grassland they consider to present a bushfire hazard and wish to have
identified as such in the bushfire-prone area dataset.
7.4 Precautionary Principle
The decision maker will need to apply the precautionary principle in identifying
bushfire-prone vegetation. There may be situations where additional information
becomes available during the verification of the draft data/map bushfire-prone
vegetation, where the precautionary principle should be applied if doubt exists.
7.5 Bushfire-Prone Buffer
Once the consolidated bushfire-prone vegetation dataset has been determined, a
100 metre bushfire-prone buffer will be created by Landgate around the bushfireprone vegetation.
Buffering of the bushfire-prone vegetation may create overlapping polygons. Where
two or more buffers overlap, they shall be merged to form a single polygon.
The bushfire-prone area, which is comprised of the bushfire-prone vegetation and
the bushfire-prone buffer, will be displayed in accordance with Section 8 of this
Standard.
Appendix 1 – Vegetation Key
PICTORIAL EXAMPLE OF VEGETATION
VEGETATION
CLASSIFICATIONS
(AS 3959-2009
CONSTRUCTION OF
VEGETATION TYPE
BUILDINGS IN
BUSHFIRE-PRONE
AREAS)
a. Forest
b. Woodland
Tall open forest
Tall woodland
Open forest
Low open forest
Pine Plantation
Woodland
Open woodland
Low woodland
Low open woodland
Open shrubland
BUSHFIRE-PRONE
VEGETATION
Yes
Yes
c. Shrubland
Closed heath
Open heath
Low shrubland
Yes
d. Scrub
Closed scrub
Open scrub
Yes
e. Mallee / Mulga
Tall shrubland
Yes
f.
Tall closed forest
Closed forest
Low closed forest
Fernland
No
Rainforest
APPLICATION OF ‘PRECAUTIONARY
PRINCIPLE’
(REFER TO SECTION 7.4)
Isolated clumps of trees maybe
possible BPV if unmanaged grasslands
flammability changes due to ephemeral
grass growth following above-normal
rainfall events.
Isolated clumps of shrubs maybe
possible BPV if unmanaged grasslands
flammability changes due to ephemeral
grass growth following above-normal
rainfall events.
Vegetation may vary due to changing
weather conditions, requires monitoring
with consideration to climate change.
VEGETATION EXAMPLE
g. Grassland
Low open shrubland
Hummock & grassland
(e.g. spinifex, porcupine)
Savannah grasslands
Closed tussock grassland
Tussock grassland
Open tussock
Sparse open tussock
Open herbfield
Sparse open herbfield
h. Bare areas
Freshwater lakes
Mud flats
Rock outcrops
Salt lakes
Salt affected vegetation
(e.g. Forbland)
i.
Isolated areas
Chenopod shrubs
Clumps of shrubs
Clumps of trees
Samphire shrubs
Yes
Flammability may change due to
ephemeral grass growth following
above-normal rainfall events or
none/inadequate
management/maintenance.
Woodland species intermixed with
grasses increases potential for spotting.
No
If possible to isolate this vegetation type
from surrounding BPV, it is likely that
vegetation in between rocks within the
outcrop is BPV.
If unmanaged, flammability may change
due to ephemeral grass growth
following above-normal rainfall events.
Yes
Vegetation greater than 1 hectare in
size and greater than 20 metres in
width shall be considered as bushfireprone.
j.
Wetlands
k. Grasslands
(Managed)
Sedgeland
Golf Course*
Road Verge*
Town Parks*
Crop
Sown pasture
No
Vegetation may vary due to changing
weather conditions, requires monitoring
with consideration to climate change.
Grass, whether exotic or native, which
is regularly maintained at or below 100
mm. Grassland, managed in this
minimal fuel condition.
No
*Unmanaged vegetation greater than 1
hectare in size and greater than 20
metres in width (e.g. bushland within a
golf course) shall be considered as
bushfire-prone.