The composition of Swamp Sclerophyll Forest on Coastal Floodplains is primarily determined by the frequency and duration of waterlogging and the texture, salinity nutrient and moisture content of the soil. Composition also varies with latitude.
6. Swamp Sclerophyll Forest on Coastal Floodplains of the NSW North Coast, Sydney Basin and South East Corner bioregions forms part of a complex of forested and treeless wetland communities found throughout the coastal floodplains of NSW. A recent analysis of available quadrat data from these habitats identified a distinct grouping of vegetation samples attributable to this community (Keith and Scott 2005). The combination of features that distinguish Swamp Sclerophyll Forest on Coastal Floodplains from other endangered ecological communities on the coastal floodplains include: its relatively dense tree canopy dominated by Eucalyptus robusta, Melaleuca quinquenervia or E. bofryoides, the relatively infrequent occurrence of other eucalypts, Casuarina glauca or Lophostemon suaveolens; the occasional presence of rainforest elements as scattered trees or understorey plants; and the prominence of large sedges and ferns in the groundcover. It generally occupies small alluvial flats and peripheral parts of floodplains where they adjoin lithic substrates or coastal floodplains. The soils are usually waterlogged, stained black or dark grey with humus, and show little influence of saline groundwater.
31 The definition of Swamp Sclerophyll Forest also contains an extensive list of plant species found in the community
32 According to Mr Winning this definition is consistent with the committee's usual approach, describing the community as an assemblage of plant species, geographical distribution and the landforms and soils on which it occurs.
33 When Dr Clements and Mr Fanning met in December 2004 they agreed that:
... the vegetation in the drainage depressions on the low-lying lands on the subject land (as mapped approximately by Mr Fanning and as shown on Fig. 12 of the statement by Dr Clements) is Swamp Sclerophyll Forest on Coastal Floodplains, an endangered ecological community.
34 This agreement was varied when Dr Clements, Mr Winning and Mr Fanning met in May 2005. They then agreed that:
… vegetation associated with/within the "drainage lines" on the subject site is consistent with the floristic description of the endangered ecological community known as Swamp Sclerophyll Forest on Coastal Floodplains.
35 At the same time Dr Clements said:
… from the 1:25,000 topographic mapped (mapped creek lines), soil landscape mapping LHCCREMS mapping, soil, and from Dr Hazelton, geotechnical report on site, the vegetation adjoining the mapped creek lines appears to meet all of the criteria of the final determination. I conclude the vegetation in these areas is consistent with that of the listed endangered ecological community's - Swamp Sclerophyll Forest on Coastal Floodplains.
36 Conversely Mr Winning and Mr Fanning agreed that:
… the vegetation on the subject site does not constitute Swamp Sclerophyll Forest on Coastal Floodplains because:
o it is not on coastal floodplains;
o it is not associated with coastal floodplains.
In this regard we rely on the evidence of Prof. Humphries with respect to fluvial geomorphology.
37 When they met in May 2005 Prof. Humphries and Dr Hazelton agreed that this site is on the Doyalson Soil Landscape, which is an erosional system. It is not part of the Wyong Soil Landscape and is thus not part of the floodplain. Whilst small pockets of Wyong Soil Landscape could occur within the Doyalson Soil Landscape, floodplain pockets do not occur on the subject site.
38 In dealing with the determination/definition of Swamp Sclerophyll Forest, Prof. Humphries was of the opinion that:
… "associated" and "peripheral" be taken to mean directly connected with the floodplain such that the community continues without a break from the floodplain and along drainage lines to a recognisable point.
39 Dr Hazelton was of the opinion that the definition needs to be read more widely:
… "associated" and "peripheral" be taken to include the above (Prof. Humphries opinion) but, in addition, to include pockets whereby the substrate and wetness are suitable to the said vegetation community.
40 Returning to the committee's definition of Sclerophyll Forest it is necessary to consider, in addition to the plant species normally found in the community, whether the other basic requirements are satisfied by the sites. In my view, despite the detailed description of the Swamp Sclerophyll Forest by the Committee, this description is not entirely clear or unambiguous when applied to the subject site. The change of opinion by Mr Fanning when he further considered the definition in more detail is perhaps indicative of this. It also became apparent and there seems no dispute in this regard that the vegetation in the area of the drainage lines is consistent with that listed for the Sclerophyll Forest.
41 Accepting as I do that the vegetation on the sites is consistent with that listed in the definition the relevant questions to emerge are:
* Do the sites comprise one of the coastal floodplains of NSW? More particularly are the sites part of a small floodplain or are they situated where a larger floodplain adjoins lithic substrates?
* Do the sites comprise humic clay loams and sandy loams, on waterlogged or periodically inundated alluvial flats and drainage lines that are associated with coastal floodplains?
* Do the sites comprise small alluvial flats and peripheral parts of floodplains?
42 In dealing with these questions I first note and accept the general agreement between the experts that the coastal floodplain does not reach these sites. Also the sites do not comprise a floodplain pocket. Hence, for the purposes of the definition the sites do not comprise a floodplain and there was no suggestion that they adjoin a floodplain.
43 It is obvious that the site is affected by a number of drainage lines and at the day of the site inspection at least two of these had moving water in them with a number of associated areas being waterlogged. The analysis of the soils based on the borehole logs provided by the geotechnical consultants confirms that these parts of the site are subject to seasonal waterlogging.
44 But can these parts of the site be described as being "associated with humic clay loams and sandy loams" or comprise, "alluvial flats"? Dr Hazelton's description of the soils as "loose sand to loamy sand occurring as topsoil" which overlays "brown to yellow orange clayey sand" would appear to meet the former requirement. However I accept Prof. Humphries' evidence that, although the soils may be waterlogged or periodically inundated, because there is an absence of alluvium on the site it does not comprise alluvial flats. Instead as Prof. Humphries suggests the lands comprising the sites are erosional valley flats and the drainage lines across the site are essentially drainage depressions resulting from enhanced runoff associated with urbanisation over the past 120 years or so. This points to some doubt as to whether the waterlogging on the site is the result of natural processes.
45 The next question that needs to be answered is whether the drainage lines on the site are associated with coastal floodplains"? Clearly there is a kind of association with the floodplain because the drainage lines on the site eventually drain into it. However this is not what I accept as being the kind of association anticipated by the definition. In this context I accept the evidence of Mr Winning and Mr Fanning.
46 Mr Fanning described the watercourse and its vegetation between the site and the floodplain, a distance of about 400 m, as not being the same as occurs on the site and this distinction and separation points to an absence of an association. More particularly Mr Fanning describes the watercourse between the site and the floodplain as being clearly incised into the landform unlike what generally occurs on the site. Lands adjoining the watercourse here are plainly not subject to any waterlogging.
47 Mr Winning accepted the geomorphological assessment undertaken by Prof. Humphries and explained that there was an obvious natural discontinuity between the watercourse vegetation on the site and the actual floodplain vegetation downstream.
Conclusions - Swamp Sclerophyll Forest
48 Whilst the vegetation associated with the watercourse extending between the site and the floodplain includes at least some of the vegetation normally associated with the Swamp Sclerophyll Forest, there was no suggestion that this vegetation community was substantially consistent with that required by the definition. Considering this together with the nature of the watercourse and character of adjoining soils it became clear that this community can be distinguished from that on the site. I thus conclude that there is no relevant continuity of the Swamp Sclerophyll Forest community between the sites and the floodplain.
49 In the circumstances I agree that, within the meaning of the definition, the sites cannot be said to be associated with the known floodplain to the north. Not being adjoining or adjacent to the floodplain means that the sites are plainly not peripheral to it. Being separated by more than 400 m I do not accept that they are closely proximate.
50 I have thus been persuaded by the submissions made on behalf of the applicant that the vegetation on the sites does not comprise the community known as Swamp Sclerophyll Forest on Coastal Floodplains. In this regard I agree that significant weight should be given to the fact that the committee describes the Swamp Sclerophyll Forest assemblage as being "on coastal floodplains". The sites do not comprise a floodplain and this forms the basis for my conclusion here. Confirming this conclusion is my finding that the watercourses on the sites are not relevantly associated or peripheral to a floodplain. Also, whilst the vegetation on the sites is consistent with that to be found in a Swamp Sclerophyll Forest this is not sufficient to overcome the more fundamental floodplain requirement and the fact that although having waterlogged loamy soils the sites do not comprise alluvial flats.
51 Hence because of the community on the sites does not comprise Swamp Sclerophyll Forest, the question of whether a species impact statement is required does not arise.
The Squirrel Glider - Evidence
52 A cursory examination of the map depicting Habitat Conservation Priority Areas in the LMCC Region reveals the existence of vast areas of potential or likely habitat for the squirrel glider. However, Dr Smith was concerned that squirrel glider habitat is poorly protected in the Lake Macquarie local government area, being inadequately represented in national parks and dedicated conservation areas. There are about 280 ha of habitat in national parks and about 2100 ha in environment protection zones where conservation is a primary objective and a further 4600 ha in environment protection zones where conservation is a secondary objective.
53 More proximate to the sites and according to Dr Smith, remnant vegetation including and in the vicinity of the sites that is capable of supporting squirrel glider populations totals more than 100 ha. This area is referred to in his report as Metahabitat 1 and comprises five various sized habitat fragments. This metahabitat adjoins the smaller Metahabitat 2 of about 90 ha to the north and east and the larger Metahabitat 3 of more than 200 ha to the south.
54 Dr Goldingay and Dr Smith said that corridor links exist between fragments within the metahabitats and between the metahabitats themselves although Dr Davey said that there was no strategic interconnection across the sites between adjoining fragments.
55 Dr Davey and Dr Smith agreed that:
* The vegetation remnant surrounding and including the two sites is about 54 ha and is the largest fragment within Metahabitat 1, which they now consider to be in the order of 180 - 190 ha.
* The fragment is also likely to be the most important breeding, refuge and source habitat for the squirrel glider population within the metahabitat.
* The better squirrel glider habitat within this fragment comprises an area just to the north of the two sites although the site does comprise some of this better quality habitat especially in the vicinity of the watercourses.
56 When Mr Fanning and Dr Smith met in December 2004 they agreed that in relation to the sites, all native forests and woodland vegetation on the subject land constitutes suitable habitat for the squirrel glider.
57 The subsequent squirrel glider trapping exercise undertaken by Mr Winning effectively confirmed this conclusion and the likelihood that squirrel gliders exist and move throughout and between the metahabitats and the fragments.
58 Dr Davey and Dr Smith further agreed that:
* A viable local population of squirrel gliders is about 300 animals and that the number of animals likely to be displaced by the proposed developments would be less than 30. Development of the sites would result in the loss of about 4% of Metahabitat 1.
* If these developments were to proceed, the fragment in which the site is situated would be reduced to about 45 ha, which meets their minimum recommendation for a viable fragment of 40 - 45 ha.
* The habitat on the sites contributes to a connecting link and possible re-colonisation source for squirrel gliders dispersing from Metahabitat 1 to the other metahabitats. If a squirrel glider corridor were to be provided across the site this would best be provided along the drainage lines found therein because this would protect feeding habitats.
* Existing land use zonings do not provide protection for surrounding lands that comprise habitat for the squirrel gliders.
59 Whilst some habitat in the form of larger trees is to be retained on the site, Dr Smith did not agree that this would offset or significantly ameliorate any of the impacts on squirrel glider habitat.
60 In dealing with the test in s 5A of the EPA Act, Dr Davey and Dr Smith agreed that factors (a), (f) and (g) were relevantly applicable. They largely agreed in relation to factor (f), which in effect asks whether the habitat of the squirrel glider is adequately represented in conservation reserves (or other similar protected areas) in the region. More particularly they agreed that:
* The squirrel glider is inadequately or poorly represented in conservation reserves in the region.
* Squirrel glider habitat is adequately protected within public forest lands in the southern section of the Sydney basin bioregion. Records of squirrel gliders indicate a rarity in State forests in the Hunter and Central Coast.
* A large area of potential squirrel glider habitat occurs on conservation-zoned lands in the Lake Macquarie area although this zone does not necessarily provide for habitat protection.
61 In relation to factor (a), which asks whether the life cycle of a species is likely to be disrupted such that a viable local population of a species is likely to be placed at risk of extinction Dr Davey and Dr Smith disagreed as follows:
* Despite the small area of habitat loss they disagreed as to the significance of this loss. Dr Smith argued that the loss would be significant because it fails to protect against the risk of cumulative habitat loss, taking also into account the extent of habitat loss on the site itself and the vulnerability of Metahabitat 1 given its urban zoning. Such cumulative impacts could be avoided by setting aside and protecting significant areas of habitat in a secure tenure.
* Conversely, although recognising concerns about cumulative habitat loss Dr Davey argued that the local population of squirrel gliders is unlikely to be placed at risk of extinction by this development. Any concerns regarding cumulative habitat loss could be adequately resolved by the appropriate secure reservation of adjacent crown land to the north of the sites.
62 If these developments were to proceed Dr Smith said that in order to mitigate the impact resulting from the loss of habitat it would be necessary to enhance the corridor links across the site by for example planting trees and the provision of "glide poles on public roads". Similarly Dr Goldingay argued that any proposed development of the site must provide for an adequate dedicated corridor to link fragments so as to compensate for the loss of habitat on site.
63 Dr Davey agreed with Dr Goldingay that if the residential subdivision is to go ahead, the squirrel gliders would be advantaged by improving the corridor network and the provision of offsite corridor development and enhancement to help compensate for the squirrel glider habitat lost from the site.
64 Mr Fanning was of the opinion that appropriate corridor linkages could be provided, noting that the proposed development includes the following ameliorative measures:
* A financial contribution to protect and enhance a corridor of vegetation located primarily on the nearby public lands.
* The retention of trees in the road reserve and in the asset protection zones in residential subdivision. Restrictions as to user "vegetation management areas" are to be provided.
Conclusions - Squirrel Gliders
65 The total area of squirrel glider habitat affected by the proposals is a little less than 9 ha out of the 54 ha remnant. Whilst the fragment is important within Metahabitat 1, and although the sites contain some better quality habitat they are likely to be, by comparison, generally of lesser quality. The remaining 45 ha would be a viable habitat fragment and could most likely accommodate the displaced animals. On this basis the loss of habitat is not of great concern. However the developments as proposed would adversely affect the linkage from the remainder of the fragment across the railway line and Macquarie Road and thence to Metahabitat 2 to the south.
66 Squirrel glider access across the site to other habitat within the fragment and thence to Metahabitat 2 is presently adversely affected by the wide gap created by the presence of the railway line and Macquarie Road. In my view the residential subdivision in its present form is likely to aggravate this undesirable situation. However such impact could be mitigated by a more responsive subdivision design, vegetation retention, new trees and gliding poles that could be supplemented by a similar provision in Macquarie Road and possibly in the railway reserve.
67 Factor (a) asks whether a viable local population of species is likely to be placed at risk of extinction. Clearly these sites form part of a viable squirrel glider habitat but in my view the loss or displacement of up to 30 animals is not significant in this context. Relevant matters here comprise the quantity of the lost habitat and its quality, including whether or not there is an important corridor on the site that is utilised by the squirrel gliders to move between different parts of their habitat. It is reasonably apparent that there are areas of habitat (within the fragment in which the sites are located) to the south and east of the sites that are accessed by the sugar gliders, apparently tenuously, via the linkage across the railway line and Macquarie Road.
68 It is also relevant to consider whether the squirrel gliders that might be displaced by this development could satisfactorily utilise the remaining habitat in this fragment and I accept that this is reasonably likely. The removal of about 4% of Metahabitat 1 is a relatively small quantity and much of the habitat to be removed by the proposal is of lesser quality by comparison with the remainder of the fragment that will continue to be viable.
69 Together these matters do not in my view place the sugar glider at risk of extinction.
70 Factor (f) asks whether a threatened species or its habitat is adequately represented in conservation reserves or other similar protected areas in the region. Whilst Dr Davey and Dr Smith agreed that the squirrel glider is inadequately or poorly represented in conservation reserves in the region I do not accept that this conclusion should be determinative in the context of the s 5A test. As described earlier there are about 280 ha of squirrel glider habitat in national parks in the Lake Macquarie area and there are about 2100 ha in environment protection zones. There are a further 4600 ha of habitat in environment protection zones where conservation is a secondary objective.
71 Factor (g) relevant to these applications asks whether the development is a threatening process and clearly the removal of vegetation as its proposed would destroy habitat and cannot be anything other than a threatening process.
72 Having considered all of the evidence in relation to the squirrel gliders' habitat I have decided in terms of s 5A of the EPA Act that this does not lead to a conclusion that the squirrel gliders or their habitat, would, as a result of the proposals, be significantly affected.
73 It has also been asked in the context of s 5A whether the removal of squirrel glider habitat from residentially zoned land might become a precedent for the removal of adjoining and nearby similarly zoned land that is also squirrel glider habitat. Whilst the site and some of the adjoining crown lands to the north are zoned for residential purposes, this does not mean that I should assume what might happen on these sites will necessarily also happen on that adjoining land. Instead it is necessary for me to decide the s 5A question on the basis of the effect of the proposed development itself. In this context it is also relevant to note that the quality of the habitat on the two sites in question is, overall, not of the same quality as the remainder of the fragment to the north.
74 It is possible that others might seek to develop nearby lands in a manner similar to what is proposed here and that some cumulative impact might result, however this is not a matter which should determine the Section 5A question. I so conclude in the absence of knowledge as to the likelihood of what, if anything, might be proposed for these lands and what the circumstances and outcome of any such applications might be.
75 In all of the circumstances I have decided that pursuant to s 78A(8)(b) of the EPA Act the proposed subdivisions and residential development are not likely to have a significant effect on the squirrel gliders and their habitat so as to require the preparation of a species impact statement.
76 It is nevertheless necessary to determine the applications on their merits and in so doing it is necessary to decide whether or not it would be acceptable for the proposed removal of the squirrel glider habitat on the site. For essentially the same reasons I have given in determining the species impact statement question I have decided that this can occur. A further reason in support of this conclusion, is the fact that the land has been zoned for residential purposes since 1984 and that this residential zoning was recently reaffirmed with the making of LEP 2004. The existing subdivision pattern, including roads and allotments, which is to be modified by this proposal lends some additional support to the two proposals.
77 I accept that the precautionary principle can be brought to bear in matters such as this, but this need not be applied in relation to these applications. This is because; taking into account the extensive and sufficient evidence provided by the experts, I have a sufficient understanding of the implications of the proposals to enable their determination.
78 Despite these conclusions, it is clear that the squirrel glider habitat on the sites effectively comprises corridors used by the gliders to travel between fragments and metahabitats. The experts agree that maintaining a corridor on and around the site of the residential subdivision would be of benefit to the squirrel gliders, a vulnerable species and I am satisfied that this can and should be provided as part of the residential subdivision design.
79 I have already agreed that the squirrel gliders are not likely to be significantly affected by the proposals but this does not mean that their vulnerability should not be given some weight in determining these development applications. In this context, whilst recognising that certain habitat trees are to be retained and vegetation management areas provided, I am not convinced that these ameliorative measures are sufficient.
Stormwater drainage - Evidence
80 Mr Engelbrecht provided with his report, a plan titled Proposed Concept Stormwater System Schematic Layout ("the drainage plan"). This drainage plan is a revised version of three earlier drainage plans. It is purpose designed for these sites to ensure that pollution and water flow is controlled so as to protect downstream catchments. Artificial water table recharge and on-site reuse of stormwater are incorporated in the design.
81 The drainage plan provides for the collection and disposal of stormwater from the residential subdivision and the small lot development as well as the stormwater that would otherwise flow into the site generally from the southwest and the southeast. The drainage plan incorporates centrally located water quality control ponds ("the control ponds"). Stormwater detention within individual allotments is also proposed. All stormwater from these control ponds is to be discharged onto land to the north via a common energy dissipating outlet headwall comprising a 40 m long perforated weir ("the stormwater outlet"). Stormwater from the southeast is to bypass the control ponds but will be discharged from the stormwater outlet.
82 Matters discussed at length in the joint report of Mr Engelbrecht and Prof. Jamieson include the control ponds, the outlet controls, bifurcation details, hydraulic grade lines and kerb inlet pits. In their conclusion the fundamental areas of disagreement relate to:
1. The extent of design detail and associated design modelling data including existing and proposed conditions deemed necessary to reasonably assess the technical viability of the new stormwater management system proposed for the development, and
2. Differing opinions as to the function and importance of the existing swales/watercourses within the proposed development site, and
3. Differing opinions as to the ecological sensitivity of the site and surrounds.
83 Prof. Jamieson was essentially concerned that the proposed control measures would not adequately control stormwater discharge or nutrient export from the site. There was much argument in relation to the size of the control ponds. Prof. Jamieson argued that the ponds were far too small, because Mr Engelbrecht's calculations were based on a soil particle size that was too small and a catchment area that was also too small. Excessive siltation is anticipated. Mr Engelbrecht said that he utilised the available geotechnical information from Douglas Partners to determine the relevant soil particle size and understand likely nutrient content and was able to conclude that the treated runoff from the site would be improved by comparison with what presently occurs.