Summary - City of Gosnells

Methods 21Table 3.2: Bush and Wetland Vegetation Condition (adapted from Government of Western Australia, 2000)Code Condition Description of VegetationP Pristine No obvious signs of disturbance.EVGGDCDExcellentVery goodGoodDegradedCompletelydegradedVegetation structure characteristic of the vegetation type remains intact, disturbance affectsindividual species only, and weeds are non-aggressive species.Vegetation structure altered somewhat; obvious signs of disturbance, but recovering. Some highlyinvasive weeds may be present at low abundance.Vegetation structure modified significantly (and/or floristic composition somewhat altered) byvery obvious multiple disturbances but ability to regenerate is retained (by, e.g. recruitment ofnative species from abundant soil seed bank).Vegetation structure and floristic composition severely impacted by disturbance; scope forregeneration but not to a state approaching good (sic) condition without intensive managementVegetation structure no longer intact; the area almost completely without native species, e.g.isolated native trees or shrubs over pasture (‘parkland cleared’).TC Totally cleared No native vegetation remaining on site.3.3 Wetland AssessmentThe term ‘wetland’ is defined under the Western Australian Environmental Protection Act, 1986 as ‘an areaof seasonally, intermittently or permanently waterlogged or inundated land, whether natural or otherwise,and includes a lake, swamp, marsh, spring, dampland, tidal flat or estuary’.Wetlands of the Swan Coastal Plain, from Wedge Island in the north to Dunsborough in the south, have beencomprehensively surveyed at a broad scale in Hill et al. (1996). In this survey work (covering approximately362,000 ha of wetlands) the wetlands were classified according to the geomorphic wetlands classificationsystem of Semeniuk (1987) and Semeniuk and Semeniuk (1995), mapped and evaluated for managementcategory. This survey forms the basis of the current Department of Environment and Conservation SwanCoastal Plain Wetlands Datasets and Atlas (DEC, 2008a, 2008b, 2008c). In this electronic dataset, eachwetland has been:• classified and allocated to a Consanguineous Suite (after Semeniuk, 1987);• given a unique number that is known as a Unique Function Identifier (UFI); and• allocated to a management category viz. Conservation Category Wetland (CCW), Resource EnhancementWetland (REW) or Multiple Use Wetland (MUW). These management categories are defined in theevaluation section (3.3.3) below.The Swan Coastal Plain Wetlands Dataset is recognised and endorsed as a guide to planning and decisionmaking by all relevant agencies in Western Australia, including representatives of the Western AustralianDepartment of Environment and Conservation, Western Australian Department of Planning andInfrastructure, Western Australian Department of Agriculture and Food, local government and communityconservation groups.The SCP Wetlands Dataset is maintained and updated, when required, by the Western Australian Departmentof Environment and Conservation. These updates are only carried out after rigorous assessments based onwell-documented, scientific evidence and are usually related to the scale of the mapping and the provision ofadditional biological data (DEC, 2007). The wetland mapping carried out by Hill et al (1996), and other datacontributing to the SCP Wetlands Dataset, was at a scale of about 1:25,000. In this mapping, small elevationdifferences were beyond the scale of the mapping but may contribute to the reclassification of wetlands (orparts of wetlands) as reliable data become available at finer scales. There are also sometimes smalldiscrepancies between the broad scale at which the dataset was originally captured and the finer scales atwhich this dataset can now be viewed. Biological data are often valuable in recognising additionalconservation values in the wetlands mapped in the SCP Wetlands Dataset.DEC (2007) outlines some of the information required to assess requests to modify the dataset. Essentiallythe collection of such information requires wetland identification, wetland delineation, wetland classificationTauss, C. and Weston, A.S. (2010). The flora, vegetation and wetlands of the Maddington-Kenwick Strategic Employment Area.A survey of the rural lands in the vicinity of the Greater Brixton Street Wetlands. Report to the City of Gosnells, W.A. Version 18.04.10