Download Appendix G – Assessment against Ten Clearing

Appendix G – Assessment against Ten Clearing
Principles
GHD | Report for Main Roads Western Australia - Margaret River Perimeter Road, 61/27189
Principle
Number
Principle
Assessment
Outcome
(a)
Native vegetation should
not be cleared if it
comprises a high level of
biological diversity.
The majority of the proposed alignment traverses through cleared agricultural land which
contains some individual stands and patches of mature Jarrah and Marri trees. The alignment
also traverses pine plantations, native bushland, conservation reserve, and existing roads and
private properties. 5.2 ha of the alignment contains remnant vegetation in good to very good
condition. The dominant vegetation community within the project area is Jarrah (Eucalyptus
marginata) and Marri (Corymbia calophylla) Open Forest with Peppermint (Agonis flexuosa)
dominant along rivers and drainage lines. No Priority Ecological Communities (PECs) have
been recorded within the project area.
The proposal may
be at variance to the
principle.
No Priority listed fauna were recorded in the study area during the field survey, although five
Priority fauna species have previously been recorded within 5 km (NatureMap, 2011). Three
fauna species listed as Vulnerable under the EPBC Act and Schedule 1 under the WC Act
were recorded within the Project Area during the field survey (Baudin’s Black Cockatoo,
Western Ringtail Possum and Forest Red-tailed Black Cockatoo)
No Threatened flora were recorded in the study area during the field survey, although one
Priority flora species Gastrolobium formosum (P3) was recorded, with a targeted search in
Spring 2012 identifying approximately 400 individuals at a cover of 70%. Additionally,
approximately 200 plants at a similar cover were identified on the banks of the Margaret River,
within 50 m of the Project Area, indicating that the species occurs at similar densities and is
not confined to the Project Area.
Vegetation within the project area is considered to represent moderate species diversity, with a
total of 168 taxa from 52 families recorded, of which 34 are introduced species. The vegetation
has had a combination of previous disturbances including large-scale clearing, roads/tracks
and logging. Given the relatively small size of the project area and the availability of similar
vegetation in the surrounding area, the loss of vegetation within the project area is unlikely to
significantly reduce the biodiversity of the local area.
(b)
Native vegetation should
not be cleared if it
comprises the whole or part
of, or is necessary for the
maintenance of, a
significant habitat for fauna
indigenous Western
Australia.
The desktop queries identified twelve EPBC Act and WC Act threatened species and a further
five marine and/or migratory bird species as potentially occurring within the study area. Six
additional DEC listed Priority fauna species have been recorded within 5 km of the Project.
Three fauna species listed as Vulnerable under the EPBC Act and Schedule 1 under the WC
Act were recorded within the Project Area during the field survey, including Baudin’s Black
Cockatoo, Western Ringtail Possum and Forest Red-tailed Black Cockatoo. Additionally, the
Southern Brush-tailed Phascogale which is also listed as Vulnerable and in Schedule 1, was
recorded in the nearby Lot 2150. There is potential that this species also occurs within remnant
GHD | Report for Main Roads Western Australia - Margaret River Perimeter Road, 61/27189
The proposal may
be at variance to the
principle.
Principle
Number
Principle
Assessment
Outcome
vegetation within the alignment.
Within the Project Area there is a total of 4.64 ha of potential Black Cockatoo feeding habitat.
There are 41 trees (Jarrah/Marri/eucalypt stags) within the Project Area which contain nesting
hollows suitable for Black Cockatoo breeding. A further 171 trees were identified as a size
suitable for the development of nesting hollows (>500 mm DBH) within the next 100 years.
During the field survey three Western Ringtail Possums were observed active at night along
riparian vegetation in the northern section of the alignment. Two dreys (resting platforms in
trees) were also recorded in this area. Droppings were also recorded along Margaret River in
the riparian vegetation and in the valley of Lot 2150. One hundred and twenty-three large
Eucalypts were recorded within the alignment with hollows suitable for this species. The area
of habitat that Western Ringtail Possums may utilise is approximately 0.86ha.
(c)
Native vegetation should
not be cleared if it includes,
or is necessary for the
continued existence of, rare
flora.
No Threatened flora species listed under the WC Act or EPBC Act have been recorded within
the project area.
The proposal is not
at variance with the
principle.
(d)
Native vegetation should
not be cleared if it
comprises the whole or a
part of, or is necessary for
the maintenance of, a
threatened ecological
community.
There are no known Threatened Ecological Communities (TECs) within 5 km of the project
area.
The proposal is not
at variance with the
principle.
Native vegetation should
not be cleared if it is
significant as a remnant of
native vegetation in an area
that has been extensively
cleared.
The vegetation within the project area is described as predominantly Beard vegetation
association 3, with a small section in the north of the project area described as Beard
vegetation association 1. The Mattiske vegetation complexes within the Project Area include
Cowaramup (C1), Cowaramup (CW1) and Wilyabrub (W1).
(e)
No TECs were recorded within the project area during the field survey.
The extent of the vegetation complexes C1 and CW1 are considered to be Depleted, i.e.
between 30% and 50% of pre-European extent remaining. The extent of the vegetation
complex W1 and Beard vegetation associations 1 and 3 are considered of Least Concern, i.e.
intact, with over 50% of the pre-European extents remaining.
The Beard and Mattiske vegetation associations and complexes present in the study area all
62 | GHD | Report for Main Roads Western Australia - Margaret River Perimeter Road, 61/27189
The proposal is not
at variance with the
Principle.
Principle
Number
Principle
Assessment
Outcome
retain more than the threshold level (30%) recommended in the National Objectives Targets
for Biodiveristy Conservation, below which species loss appears to accelerate exponentially at
an ecosystem level (Commonwealth of Western Australia, 2001). Furthermore, the study area
does not occur within an extensively cleared landscape as approximately 67% of preEuropean vegetation extent remains in the Shire of Augusta-Margaret River.
Main Roads have proposed to offset the loss of vegetation as a result of the proposed project.
(f)
(g)
Native vegetation should
not be cleared if it is
growing in or in association
with a watercourse or
wetland.
Native vegetation should
not be cleared if the
clearing of the vegetation is
likely to cause appreciable
land degradation.
There are no listed significant wetlands or watercourses within the project area. However, the
Project Area traverses a section of the Margaret River and Darch Brook. Vegetation
associated with these waterways includes Jarrah-Marri-Peppermint Forest and Closed Scrub
of Melaleuca spp. over mixed Sedgeland.
The proposal is at
variance with the
Principle.
Water flow within these waterways will be maintained and where possible no diversion of
watercourses be carried out. Direct impact on riparian vegetation and associated habitat
should be avoided wherever possible. Vegetation retention within drainage lines will help
prevent erosion and flooding and prevent potential deleterious impacts on downstream areas.
The soils within the project area consist of loamy gravels, duplex sandy gravels, semi-wet soils
and grey deep sand duplexes with some granite outcropping. Soil erosion and water erosion
may occur on these soils, particularly along the river and creeklines. The clearing of native
vegetation may cause some alteration to the health of adjacent lands including the
introduction/spread of dieback, soil erosion and runoff and weed dispersal.
The proposal is
unlikely to be at
variance with the
Principle.
The dieback assessment identified dieback within the transmission line easement, with the
remnant vegetation to the north and south of this line being downslope. Consequently,
dieback is likely to have infiltrated these areas of the State Forest and Bramley National Park.
Main Roads has experience at addressing these issues on other projects and given
appropriate management, the Project is unlikely to result in appreciable land degradation.
Specific management actions will be implemented for the management of dieback, runoff,
erosion, invasive species (weeds) and fire, with these incorporated into the CEMP.
(h)
Native vegetation should
not be cleared if the
clearing of the vegetation is
likely to have an impact on
the environmental values of
any adjacent or nearby
There are no Environmentally Sensitive Areas (ESAs) within or in close proximity to the study
area.
North of the Margaret River crossing, the alignment traverses Keenan State Forest and timber
reserve and lies adjacent to the Bramley National Park. This section of the alignment was
excluded from the National Park by request from Main Roads and the Shire of Augusta-
The proposal may
be at variance with
the Principle
GHD | Report for Main Roads Western Australia - Margaret River Perimeter Road, 61/27189 |
Principle
Number
Principle
Assessment
conservation area.
Margaret River, although 0.54 ha of the National Park will require excision.
Outcome
The proposed road will create a barrier for fauna movement between the western and eastern
boundaries of the alignment within the National Park. However Main Roads have proposed to
create wildlife corridors along the alignment to facilitate the movement of fauna between
conservation areas.
To reduce potential impacts associated with clearing within the section of remnant vegetation
within and/or adjacent to the Bramley National Park, specific management actions for flora and
fauna, dieback, erosion and invasive species (weeds) and fire should be incorporated in to the
CEMP.
(i)
Native vegetation should
not be cleared if the
clearing of the vegetation is
likely to cause deterioration
in the quality of surface or
underground water.
The Project Area traverses the Margaret River and Darch Brook, and as such there is a risk of
runoff with additional sediment entering these waterways during construction. A CEMP will be
prepared which includes management actions to address these potential impacts.
Detail design should include consideration of water management such that there is no direct
runoff to the water courses, and to stabilising the banks of the watercourse following
construction.
The proposal is
unlikely to be at
variance with the
Principle
The groundwater salinity in the area is low. Given the scale of the proposed clearing, and the
fact that the majority of the Project Area has been cleared for agriculture, it is unlikely to result
in a deterioration of underground water quality.
(j)
Native vegetation should
not be cleared if the
clearing of the vegetation is
likely to cause, or
exacerbate, the intensity of
flooding.
A large proportion of the project area is presently cleared for agricultural purposes or consists
of planted/introduced species. Given the nature of the soil within the project area and the scale
and linear nature of the proposed clearing, it is not considered likely to cause, or exacerbate,
the intensity of flooding.
Any potential impacts will be managed through design and in the CEMP.
64 | GHD | Report for Main Roads Western Australia - Margaret River Perimeter Road, 61/27189
The proposal is not
at variance with the
Principle.