Richmond Bridge and Approaches Study

7 Environmental considerations In conjunction with the development of options, preliminary environmental investigations were undertaken for the study area. The results of these were used to identify the existing environment in the area and any potential constraints for the options being considered. As part of this investigation, desktop environmental searches were undertaken for the study area. This was followed by a field investigation through the study area, however it was limited to public spaces, such as the road corridor and river bank. No field investigations were undertaken on private land. The results of the preliminary environmental investigations are outlined below. In general, because all options are the same through the townships of Richmond and North Richmond, the environmental constraints in these areas would be consistent for all options. In addition, options across the flood plain and Hawkesbury River all occur within about a 50 metre corridor, therefore the environmental constraints in these areas would also be similar for all options. The main distinctions between the constraints are: • The options closest to the existing road corridor (options A and B) may have higher Aboriginal and non- Aboriginal constraints through the flood plain and across the river. • Options C and D would require more property acquisition as they have a wider road corridor. • Option C and D may require more flood and hydrology management due to the height of the new road embankment across the flood plain. However these options would also provide a higher level of flood immunity for the local community. 7.1 Biodiversity The study area is dominated by cleared land with patches of remnant native vegetation along the southern bank of the Hawkesbury River and freshwater wetlands on alluvial floodplains. Where remnant stands of native vegetation occur in the study area, they are generally considered to be of high conservation significance due to their threatened status. Searches of the following ecological databases were conducted for locations within 10 kilometres of the study area: • Atlas of NSW Wildlife for threatened fauna records. • NSW Government Department of Primary Industries (DPI) ‘Fishing and Aquaculture’ records. • Protected Matters (EPBC Act) database. The results of these searches and preliminary field investigations are outlined below. Species/communities that may represent an environmental constraint for this project have been mapped and are identified in Figure 23 – Environmental constraints on page 39. 7.1.1 Vegetation communities The desktop assessment identified four threatened vegetation communities under the NSW Threatened Species Conservation Act 1995 (TSC Act) and one endangered ecological community (EEC) listed under the Commonwealth Environmental Protection and Biodiversity Conservation Act 1999 as potentially occurring within the study area. A preliminary site survey was undertaken to verify the desktop assessment. This confirmed that the study area contains two EECs listed under the TSC Act. These are: • River-flat eucalypt forest on coastal floodplains of the NSW North Coast, Sydney Basin and South East Corner bioregions (mapped as Alluvial Woodland and Riparian Forest in NPWS mapping). • Freshwater wetlands on coastal floodplains of the NSW North Coast, Sydney Basin and South East Corner bioregions. The River-flat forest on the northern bank of the Hawkesbury River within the study area is highly disturbed mown parkland and on the southern bank the overstorey canopy is intact but the ground cover is highly infested with weedy vines. Pugh’s Lagoon is part of the EEC, Freshwater wetlands on coastal floodplains of the NSW North Coast, Sydney Basin and South East Corner bioregions and is also a highly disturbed area, however it is in a moderately good condition. 36 7.1.2 Flora The desktop search indicated that 25 threatened flora species listed in the TSC Act were previously recorded within ten kilometres of the study area. 24 of these species were also identified in the EPBC protected matters search. Each of these species has been assessed to determine its likelihood of occurring within the study area based on vegetation communities present, habitats present and from observations during the site inspection. Of the threatened flora species considered from the desktop search, none were found on site following the ecological site inspection and one species was considered to potentially occur in the study area, based on habitat assessment. This is the Pomaderris brunnea (Rufous Pomaderris), listed as vulnerable under the TSC Act and the EPBC Act. This species typically grows in moist woodland or forest on clay and alluvial soils of flood plains and creek lines. Several potentially hollow bearing trees exist within the riparian forest on the southern bank of the Hawkesbury River, in the vicinity of Richmond Bridge. 7.1.3 Weeds The desktop search identified 98 noxious weed species listed within the Hawkesbury LGA. During the field ecological survey, twelve noxious weeds species, in three different habitats, were observed within the study area. Vegetation along the road verges is dominated by the following noxious weeds: • Small and Large Leaved Privet. • Lantana. • Giant Parramatta Grass. The riparian forest is heavily infested with the following noxious weeds: • Moth Vine. • Madiera Vine. • Balloon Vine. • Morning Glory. • Wandering Jew. Waterways observed in the study area contained the following noxious weeds: • Alligator Weed. • Water Hyacinth. • Salvinia. • Cabomba. 7.1.4 Fauna Database searches revealed 55 threatened fauna species known or likely to occur within 10 kilometres of the study area. These included: • Seven bat species. • 16 bird species (including 11 migratory species). • Two fish species. • Six frog species. • Three insect species. • Five marsupial species. • One reptile species. • One rodent species. • One snail species. No threatened fauna species were physically observed during the field investigation. No microchiropteran bats were observed in the study area nor was there any evidence of current or past roosting (i.e. guano marks). No bat noises were recorded on the ANABAT detector. An assessment of likely occurrence has been made for these fauna species on the basis of available habitat and other identifiers. Of the 55 threatened species identified in the desktop search, 29 are considered as potentially occurring in the study area. 37 7.1.5 Aquatic environments and species Hawkesbury River Within the Hawkesbury River there are two main aquatic habitats within the study area. These are ‘run’ (areas of moderately flowing water in the middle of the river) and ‘pool’ (still areas of water along the riverbanks). Shading is restricted to the banks of the river. The northern bank of the river at Richmond Bridge is lined with a narrow band of Swamp Oak, with sparse groundcover, evidence of recent flood damage, fallen timber and clumps of aquatic weeds including Salvinia, Cabomba and Alligator Weed. River-flat forest with dense Swamp Oak and a number of large eucalypt trees occurs in a band up to 50 metres wide along the southern bank of the Hawkesbury River adjacent to Richmond Bridge. This vegetation provides protection and nutrient input for aquatic habitat. Key fish habitat includes all marine and estuarine habitats up to highest tide level (as reached by ‘king’ tides, DPI 2011a) as occurs in the study area. DPI’s key fish habitat maps indicate that the Hawkesbury River at Richmond Bridge represents important aquatic habitat to support local fish communities. There are no SEPP 14 listed wetlands in the study area or the surrounding area. No wetlands listed on the NSW Directory of Important Wetlands occur within the study area. There are several small freshwater lagoons within the study area, see below. Pugh’s Lagoon Pugh’s Lagoon, situated on the floodplain between Richmond and the Hawkesbury River, is located just to the north of the Richmond township. It is a wetland in moderately good condition with very few weeds, but is straddled by Kurrajong Road. The lagoon comprises a series of small ponds that contain fringing vegetation of emergent macrophytes, such as species of Typha and Phragmites. The lagoon is part of the EEC, Freshwater wetlands on coastal floodplains of the NSW North Coast, Sydney Basin and South East Corner bioregions. It is noted that this area is incorrectly mapped as Alluvial Woodland in the NPWS vegetation mapping. The Green and Golden Bell Frog was not recorded during the site investigation and is not recorded within the Hawkesbury River, however this species is known to occur in local tributaries and is also often found within other highly disturbed areas within the greater Sydney region that are effectively similar to the environmental conditions existing at Pugh’s Lagoon. Therefore there is some potential that this species may be present as habitat for this species is present within the study area. Table 16 summarises the constraints relating to biodiversity. Table 16 - Constraints relating to aspects of biodiversity Aspect Constraint Biodiversity • Low quality River-flat eucalypt forest on coastal floodplains (of the NSW North Coast, Sydney Basin and South East Corner bioregions) endangered ecological community exists within the study area along the banks of the Hawkesbury River. This constraint is common for all options. • Freshwater wetlands on coastal floodplains (of the NSW North Coast, Sydney Basin and South East Corner bioregions) endangered ecological community

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