18.3 Assessment of potential impacts
18.3.1 Terrestrial flora
Loss of vegetation (including native vegetation)
There is no native vegetation (as defined by the FBA) located within the project footprint. Around 1,675 trees would potentially require removal to facilitate the project. Based on the current concept design for the project, it is unlikely these trees could be retained. Of these trees, around 107 have been identified has having a high retention value in accordance with the Institute of Australian Consulting Arboriculturists Significance of a Tree, Assessment Rating System (refer to Annexure G of Appendix S (Technical working paper: Biodiversity)).
The majority of trees to be removed are located at Rozelle around the Rozelle Rail Yards and associated surface road upgrades and active transport connections. This includes trees within the Rozelle Rail Yards and Ports Authority land (those remaining following site management works), along City West Link and Lilyfield Road, and areas adjacent to Whites Creek at The Crescent and Brenan Street.
Around 355 trees were identified to be investigated further during detailed design to determine their suitability for retention, 34 of which were identified as high retention value. These trees include groups of trees along Lilyfield Road and on the approaches to Anzac Bridge that may offer visual screening.
Trees to be retained would be protected in accordance with Australian Standard (AS) 4970-2009 Protection of trees on development sites and suitable ground protection measures to protect the tree protection zone. Tree removal would be carried out by a suitably qualified arborist and in accordance with AS 4373-2007 Pruning of Amenity Trees and the NSW WorkCover Code of Practice for the Amenity Tree Industry (1998).
This assessment has been based on the current project footprint and concept design for the project. Further opportunities to retain trees may emerge during detailed design. All opportunities for retaining additional trees through tree sensitive design and construction methods would be considered. Where retention of trees is not possible, compensatory planting would be carried out. Replacement trees should be planted within, or close to, the project footprint where feasible and practicable.
Compensatory planting would seek to use opportunities presented by the new open space at the Rozelle Rail Yards, including along Lilyfield Road and City West Link and the remaining project land at Iron Cove Link, to be consistent with the Urban Design and Landscape Plan (see section 18.5) to be developed for the project.
Removal of threatened flora
The project would not involve the removal of any threatened flora species listed under the TSC Act or EPBC Act.
Spread of weeds
As part of the site management works, most of the weeds within the Rozelle Rail Yards would be removed. Weeds throughout the remainder of the study area (and in other parts of the Rozelle Rail Yards east of Victoria Road) are intermittent. Given the presence of weeds in the study area, there is potential for disturbance of vegetation to lead to the spread and/or intensification of weeds. If not appropriately managed, this may indirectly affect native flora and fauna in adjoining areas by further reducing habitat quality, altering the structure and composition of vegetation and increasing competition for resources.
The implementation of management measures outlined in section 18.5 would minimise the potential for the spread of weeds from construction activities.
18.3.2 Terrestrial fauna
With regard to biodiversity, edge effects are changes in population or community structures that occur at the boundary of two habitats. No remnant native vegetation occurs within the study area. Therefore, edge effects on native vegetation are not considered likely to occur as a result of the project. Habitat for native species within the study area includes non-remnant native and exotic vegetation (such as planted street trees and exotic species). Edge effects on these areas are likely to occur, but would be limited through the implementation of mitigation measures outlined in section 18.5.
Fauna injury and mortality of fauna
Fauna injury or mortality could occur during construction of the project, as a result of direct collision with vehicles and equipment within the project footprint. Mobile species (such as birds) may be able to move away quickly and easily, but other less mobile species, or those with high fidelity with their home range, may be slower to move away or may not relocate at all, potentially resulting in injury or mortality of the individual.
During construction at the Rozelle Rail Yards (including demolition of the Victoria Road bridge), there is potential for the Eastern Bentwing-bat to be injured or stressed due to disturbances associated with noise, dust or light while roosting in the cavities of the bridge. Direct mortality or injury is unlikely to occur to the Grey-headed Flying-fox as a result of the works, as the species is highly mobile. Individuals are likely to actively avoid the area during construction.
Although there is potential for some injury or mortality of fauna species, the project is unlikely to result in a large number of fauna injury or mortality incidents, as the majority of the project would be constructed underground. Where temporary and permanent ancillary facilities and infrastructure occur, the surrounding land is highly urbanised.
Implementation of management measures outlined in section 18.5 would reduce the chances of injury or mortality of fauna. Measures to manage potential impacts on bats would be included in the Construction Flora and Fauna Management Plan, which would include specific measures identified for the Victoria Road bridge.
Impact on migratory species
No migratory species are expected to occur in the project footprint, given the absence of suitable habitat and the highly urbanised environment. A total of 40 migratory species are either known to occur, or have been assessed as likely to occur, within the study area, however outside of the project footprint. The project is therefore unlikely to impact migratory species (refer to Appendix S (Technical working paper: Biodiversity)).
Threatened fauna and loss of habitat
There is potential for direct and indirect impacts on the Grey-headed Flying-fox, Eastern Bentwing-bat and Yellow-bellied Sheathtail-bat as a result of the project.
Grey-headed Flying-fox impact
The Grey-headed Flying-fox is listed as ‘vulnerable’ under the EPBC Act and is therefore considered a MNES. This species is considered likely to forage on around 4.49 hectares of mapped urban exotic and native cover comprising feed trees around that would be removed by the project (foraging habitat). This area does not include vegetation within the Rozelle Rail Yards that will be removed as part of the site management works. This loss of foraging habitat is considered negligible in the context of similar available habitat within the foraging range for this species. A cumulative assessment of the impact on biodiversity, including the Grey-headed Flying-fox, is included in Chapter 26 (Cumulative
While the species was not sighted during targeted field surveys for other species, known records exist close to the study area. The project would not impact roosting sites or known breeding camps located at the Royal Botanic Gardens in Sydney, around three kilometres east of the Rozelle interchange and at Turrella, around four kilometres southeast of the St Peters interchange.
Indirect impacts of the project also have the potential to affect the Grey-headed Flying-fox. Construction noise and vibration would be generated by the works, and lighting would be required during standard construction hours (to brighten dark areas such as under the Victoria Road bridge) and during out-of-hours (night) works. These types of indirect impacts are already widespread within the highly urbanised study area, and any exacerbation of these impacts would be managed by the implementation of mitigation measures outlined in section 18.5.
Furthermore, night construction works would likely deter Grey-headed Flying-fox individuals from foraging within or immediately adjacent to the project footprint. Construction noise, vibration and lighting impacts would be temporary and are not expected to significantly impact the Grey-headed Flying-fox.
An assessment in accordance with criteria under the Matter of National Environmental Significance Significant Impact Guidelines (Commonwealth of Australia 2013) for this species was undertaken and is provided in Annexure E of Appendix S (Technical working paper: Biodiversity). This assessment concluded that a significant impact on the Grey-headed Flying-fox is unlikely to occur as a result of the project.
Impact on microbats (Eastern Bentwing-bat and Yellow-bellied Sheathtail-bat)
The project would require the demolition of Victoria Road bridge. The cavities of the bridge have been identified as a potential roosting site for the Eastern Bentwing-bat (non-breeding / maternal roost). No maternity colonies for the Eastern Bentwing-bat are known within the Sydney Metropolitan Catchment Management Authority area (OEH 2016a). This species breeds at maternal roosting sites within limestone caves and migrates to Sydney and other areas for winter, returning to maternal roosts in
The Eastern Bentwing-bat is most at risk from indirect impacts associated with noise, vibration, light and dust during construction. The works for the Rozelle interchange would occur during standard construction hours and out-of-hours (night) works, and the impacts of noise, dust and vibration are expected to occur continuously during this time. However, separation distances from these activities to the Victoria Road bridge where potential roost sites exist (before its demolition), would minimise these impacts.
There is potential for noise, light and/ or vibration impacts on the Eastern Bentwing-bat to occur at the new Victoria Road bridge during operation as a result of additional surface road traffic and associated increases in lighting and noise impacts. These potential impacts are not expected to be significant as the Eastern Bentwing-bat is a highly mobile species and the bridge has been identified as only providing a potential non-breeding/maternal roost site.
Whites Creek bridge was also assessed for potential microbat habitat. No microbats were considered likely to occur at Whites Creek bridge. Of the 4.49 hectares of vegetation being removed for the project and comprising potential foraging habitat for the Grey-headed Flying-fox, around 3.78 hectares of vegetation has been identified as potential foraging habitat for the Eastern Bentwing-bat. This small loss of foraging habitat would have a minor impact on the Eastern Bentwing-bat.
Construction noise, vibration, light and dust are not expected to have a significant impact on the Yellow-bellied Sheathtail-bat as it is considered likely that this species only visits this area for foraging habitat and does not rely on this area as a roosting site.
18.3.3 Loss of aquatic biodiversity
The surface water and flooding assessment for the project (refer to Appendix Q (Technical working paper: Surface water and flooding)) has determined that the project would have no adverse surface water quality impacts (including Whites Creek), based on the implementation of appropriate management measures and the fact that the residual risk to the environment is low (refer to Chapter 15 (Soil and water quality)).
Suitable habitat for marine species is not considered present, or is unlikely to be present, within the study area. Further, impacts on aquatic habitat downstream of the project are not expected. Water quality impacts such that they would affect marine species, or their habitat, are not expected at Dobroyd Canal (Iron Cove Creek), Hawthorne Canal, Iron Cove estuary, Whites Creek, Johnstons Creek or Alexandra Canal. These receiving waterways are highly disturbed ecosystems and the project would generally reduce the mean annual stormwater pollutant loads being discharged to receiving waterways when compared to the existing conditions. Further details regarding water quality are provided in Chapter 15 (Soil and water quality).
The project would not directly harm marine vegetation or habitat of threatened species, communities or populations. Removal of planted riparian vegetation (non-marine) along the edges of the Whites Creek concrete channel would be required for the upgrade of the intersection of The Crescent and City West Link and the widening and improvement works to Whites Creek. Following these works, a section of the riparian corridor of Whites Creek between The Crescent and the Rozelle Bay confluence would be improved as part of the integration of the Whites Creek naturalisation works planned by Sydney Water. These naturalisation works would be carried out in consultation with Sydney Water.
The new infrastructure proposed over Whites Creek would shade the aquatic habitat within the concrete channel of Whites Creek, creating less favourable conditions for barnacles and oysters attached to the wall. This reduction in light is unlikely to change water temperature given the constant tidal movement in and out of the crossing. The increased bridge width is unlikely to act as a behavioural barrier to fish passage (as is the case with small dark culverts). The passage is considered to have adequate clearance (two to three metres above water), depth (one to two metres) and width (nine metres) to encourage fish movement.
During construction, the proposed works may temporarily obstruct fish passage during the use of a floating boom and silt curtain near the Whites Creek outlet across Rozelle Bay. A coffer dam would also be required within Rozelle Bay to facilitate piling for a pedestrian bridge and rock revetment works for the drainage outlet to Rozelle Bay. This impact would be minimal given the poor creek habitat in Whites Creek and Rozelle Bay intertidal and subtidal area. Fish passage would be restored during operation.
As part of the project, Easton Park drain would be decommissioned with flows diverted into a new channel to convey flows through the Rozelle Rail Yards. An upgraded culvert would be provided to discharge flows into Rozelle Bay. This culvert upgrade would result in the removal of around 27 metres of intertidal rock revetment wall. This intertidal habitat is in poor condition with limited aquatic value comprising few oysters and marine molluscs. A rock spillway and scour protection rock apron would replace the existing rock wall, providing a similar scale and type of intertidal habitat. There is no
marine vegetation present at this location that could be affected by changes in salinity due to freshwater discharge. The nearest sensitive vegetation is Coastal Saltmarsh, located around 300 metres east of The Crescent, which is unlikely to be affected due to its distance and mixing with tidal water. The project would not result in a net loss of key fish habitat. No direct impacts would occur to Dobroyd Canal (Iron Cove Creek), Hawthorne Canal, Iron Cove estuary, Johnstons Creek or Alexandra Canal.
Indirect impacts on aquatic habitat may occur as a result of impacts on water quality. Water quality could potentially be impacted by sediment runoff and deposition, polluted road runoff, high velocity runoff/discharge, and oil and pollutant spills entering the waterway. Uncontrolled runoff or discharge can influence the water quality in waterways, such as water temperature, turbidity, pH, salinity and alkalinity. These impacts may reduce water quality, reduce light penetration through the water column, and smother benthic habitat with sediment. This could alter primary (plant) and secondary (animal) production that supports or regulates the aquatic food web.
However, the receiving waterways are highly disturbed ecosystems and the project would generally reduce the mean annual stormwater pollutant loads being discharged to receiving waterways when compared to the existing conditions. Impacts on aquatic habitat as a result of water quality impacts during construction would be short term and would be minimised through the implementation of appropriate management measures as identified in section 18.5 and in Chapter 15 (Soil and water quality). There would be no net loss of aquatic habitat in the medium to long term.
18.3.4 Impact on groundwater dependent ecosystems
No priority GDEs were identified in the study area and therefore the project is considered unlikely to have an impact on GDEs. Long term dewatering caused by tunnel drainage could lower the water table, reducing the amount of groundwater available for shallow rooted plants. The minimum depth of the water table underlying the majority of the project is around two metres below ground surface and therefore existing plants are unlikely to be completely dependent on groundwater. Further information on groundwater is provided in Chapter 19 (Groundwater).
18.3.5 Introduction and spread of exotic species
Given the majority of the study area is disturbed and within a highly urbanised setting, it is likely that animal pests are present within the study area. The following species were recorded during field surveys at the Rozelle Rail Yards as part of the site management works investigations:
· European Red Fox (Vulpes vulpes)
· European Rabbit (Oryctolagus cuniculus)
· Feral Cat (Felis catus)
· Common Myna (Acridotheres tristis).
Given the highly urbanised nature of the remainder of the study area, these species are also considered likely to occur in other parts of the study area. The project is not likely to exacerbate the impacts of the European Red Fox or European Rabbit on native fauna, due to their existing presence in the study area, the highly urban context and the lack of native fauna. Further, the project is unlikely to increase the abundance of cats, introduce them into new areas (given the abundance of cats in the study area), or increase predation pressure on native fauna. Pathogens A number of pathogens of concern in NSW have the potential to impact native flora and fauna. Activities that involve movement of equipment over large areas are of particular concern, given the high potential to spread pathogens over large areas. Although no sign of pathogen infection was identified during the field surveys at the Rozelle Rail Yards as part of the site management works investigations, key pathogens of concern include:
· Myrtle rust (Uredo rangelli)
· Chytrid fungus (Batrachochytrium dendrobatidis)
· Phytophthora (Phytophthora cinnamomi).
Given the highly urban context and lack of existing remnant native vegetation within the study area, it is unlikely that Phytophthora is present. Myrtle rust, if present, would be limited to any landscaped or planted Eucalypts. It is considered unlikely that the Chytrid fungus (an infectious disease in amphibians) is present within the study area given the absence of frog species.
The implementation of appropriate mitigation measures listed in section 18.5 would reduce the potential for introduction of Myrtle rust and Phytophthora to be introduced into the study area during construction of the project. Where required, these pathogens would be managed through the implementation of the management measures detailed in section 18.5.
18.3.6 Impact on matters of national environmental significance
The only MNES that was considered likely to be impacted by the project is the Grey-headed Flyingfox, listed as Vulnerable under the EPBC Act. This species was considered likely to forage on a limited number of feed trees within up to 4.49 hectares of mapped urban and exotic native cover to be removed by the project. Potential impacts of the project on this species include:
· Removal of up to 4.49 hectares of potential foraging habitat within the study area
· Disturbance from construction noise, vibration and lighting.
An assessment in accordance with criterion under the Matter of National Environmental Significance Significant Impact Guidelines (Commonwealth of Australia 2013) for this species was undertaken and is provided in Annexure E of Appendix S (Technical working paper: Biodiversity). This assessment concluded that a significant impact on the Grey-headed Flying-fox is unlikely to occur as a result of the project. No impacts on a known camp would occur as a result of the project and no species offsets are required.
As no significant impact would occur on any MNES, a referral to the Commonwealth Department of the Environment is not required and the EPBC Act assessment bilateral agreement has not been triggered for this project. Further detail is provided in Chapter 2 (Assessment process).
18.3.7 Impacts on relevant key threatening processes
The project has the potential to contribute to key threatening processes as defined by the EPBC Act, TSC Act and FM Act in relation to threatened species, communities, populations and their habitats. These are summarised in Table 18-7. With the implementation of appropriate mitigation measures, the risk of exacerbating these key threatening processes is considered to be low.
Table 18-7 Potential impacts of key threatening processes on biodiversity
Infection of native plants by Phytophthora cinnamomi TSC Act Movement of vehicles, equipment and people during the construction phase carries a risk of introduction and spread of the plant pathogen Phytophthora cinnamomi. Potential
Dieback caused by the root-rot fungus* Phytophthora cinnamomi EPBC Act
Presence of the plant pathogen within the study area is unknown. Potential
Introduction and establishment of Exotic Rust Fungi of the order Pucciniales pathogenic on plants of the family Myrtaceae TSC Act Movement of vehicles, equipment and people during the construction phase carries a risk of introduction and spread of Myrtle rust.
Presence of Myrtle rust within the study area is unknown, but would likely be limited to any landscaped or planted Eucalypts.
Invasion and establishment of exotic vines and scramblers TSC Act Exotic vines and scramblers are present within the study area including areas along road and track edges.
Movement of vehicles, equipment and people during the construction phase carries a risk of introduction and spread of these exotic vines and scramblers.
Invasion, establishment and spread of Lantana camara TSC Act L. camara is present within the Rozelle Rail Yards. Movement of vehicles, equipment and people carries a risk of introduction and spread of L. camara into unaffected areas.
Human-caused climate change TSC Act, EPBC Act and FM Act
During construction, machinery and production and transport of materials would emit carbon-dioxide into the atmosphere, which is known to increase greenhouse gases responsible for climate change.
However, the results of the greenhouse gas assessment for the project demonstrates the
benefits of road tunnel usage in urban areas, where travel along a more direct route at higher average speeds results in fewer greenhouse gas emissions being generated by road users, as reduced congestion and stop-start driving reduces the fuel used by vehicles. Further detail is provided in Chapter 22 (Greenhouse gas).
Note: *It is now understood that P. cinnamomi is not a fungus. This was the name of the key threatening process when it was registered under the EPBC Act.
18.4 Biodiversity offsets
Consistent with the SEARs, the project has been assessed using the FBA. The FBA was developed by OEH and includes a standardised methodology for the calculation of offsets. The outcome of this assessment is that no biodiversity offsets are required for this project. Details of this assessment can be found in Appendix S (Technical working paper: Biodiversity).
Replacement planting would be undertaken for the trees that would be removed by the project, as outlined in section 18.3.1 and section 18.5.
18.5 Environmental management measures
Environmental management measures relating to biodiversity during construction and operation are provided in Table 18-8. Additional mitigation and management measures relevant to biodiversity are also described in the following sections of this EIS:
· Noise and vibration management measures in Chapter 10 (Noise and vibration)
· Lighting management measures in Chapter 13 (Urban design and visual amenity)
· Erosion and sediment control management measures in Chapter 15 (Soil and water quality)
· Flooding and drainage management measures in Chapter 17 (Flooding and drainage).
Table 18-8 Environmental management measures – biodiversity
Impact on biodiversity values B1
A Construction Flora and Fauna Management Plan (CFFMP) would be developed and implemented during construction. The CFFMP would include the following:
· Identification of guidelines relevant to construction, the matters they apply to and what is required to ensure compliance
· Pre-disturbance inspection requirements to identify features of biodiversity conservation significance and select appropriate management measures and environmental controls
· Management measures and environmental controls to be implemented before and during construction including:
– An unexpected threatened species finds procedure
– Section 3.3.2 Standard precautions and mitigation measures of the Policy and guidelines for fish habitat conservation and management Update 2013 (DPIFisheries
– Tree assessment and management protocols consistent with AS 4970-2009 Protection of trees on development sites
– Weed management protocols.
Disturbance of threatened microbats B2
Prior to the commencement of any works associated with the modification of the Victoria Road bridge, an inspection would be carried out by a suitably qualified and experienced ecologist to confirm the presence of roosting microbats. If roosting microbats are identified, measures to manage potential impacts would be developed in consultation with an appropriate microbat expert and included in the CFFMP prior
to the commencement of any work with the potential to disturb the roosting locations (as confirmed by the microbat expert). The plan would include management measures outlined in Appendix S (Technical paper: Biodiversity assessment report) and from any additional assessments carried out during detailed design and project delivery as relevant.
Aquatic impacts B3
The proposed road bridge at Whites Creek would be designed with consideration of Policy and Guidelines for Fish Habitat Conservation Update 2013 (DPI, 2013) and Why do Fish Need to Cross the Road? Fish Passage Requirements for Waterway
Crossings (NSW Fisheries 2003).
Aquatic impacts B4
Site-specific Erosion and Sediment Control Plans (ESCPs) would be prepared for each work location associated with or in the vicinity of waterways and culverts that would be modified as part of the project. The ESCPs would contain measures to stabilise all surfaces disturbed as a result of the project as soon as possible following the disturbance to prevent erosion and to minimise sedimentation in adjacent aquatic
Loss of trees B5
The CFFMP will include measures to manage potential impacts on trees. Measures will include:
· The establishment of tree protection zones
· Ground protection measures for trees to be retained.
Loss of trees B6
As many trees as possible will be retained during construction. In the event that tree removal cannot be avoided, a tree replacement strategy will be prepared. Replacement trees will be included in the Urban Design and Landscape Plan to be developed and implemented for the project.
Loss of trees B7
The CFFMP will include tree management protocols and provision for the development of tree management plans (in accordance with the requirements of AS 4970-2009) where
required for specific trees. Protection of trees on development sites will be carried out in consultation with an arborist with a minimum Australian Qualifications Framework (AQF) Level 5 qualification in arboriculture for each tree proposed for retention where works associated with the project have the potential to impact on the tree root zone.
Loss of trees B8
Tree removal, pruning and maintenance work will be carried out by an arborist with a minimum AQF Level 3 qualification in accordance with AS 4373-2007 Pruning of Amenity Trees and the NSW WorkCover Code of Practice for the Amenity Tree Industry (1998) and advice provided by an arborist with a minimum AQF Level 5 qualification in arboriculture (or equivalent).
Loss of trees OB9
An Urban Design and Landscape Plan will be prepared and implemented to guide the compensatory planting for trees removed by the project. The plan will include:
· A tree replacement strategy
· Species recommendations for the landscape design to consider, including foraging trees for the Grey-headed Flying-fox
· Relevant project specific rehabilitation and revegetation measures associated with the M4 East and New M5 projects, where there is an overlap in use of project footprint.
Loss of aquatic habitat OB10
Consultation would be undertaken with Sydney Water regarding integration of naturalisation works at Whites Creek, including re-establishment of vegetation where possible following construction activities. Vegetation re-establishment will be undertaken in accordance with Guide 3: Reestablishment of native vegetation of the Biodiversity Guidelines: Protecting and management biodiversity on RTA project (NSW Roads and Traffic Authority 2011). Operation