Response to Information Request - Received on 19/04/2012 · OPW11/0335

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10.0       ENVIRONMENTAL IMPACT ASSESSMENT


The environmental             impact of stormwater from the development was assessed using the
accepted      solutions for managing stormwater quality in South East Queensland. The Water
Sensitive Urban Design Deemed to Comply Solutions for South East Queensland (henceforth
termed "the Solutions") outlines a seven step process for selecting and designing stormwater
management solutions, to achieve the stormwater management outcomes required by the
Department of Environment and Resource Management (DERM)(2009). The Solutions identify
acceptable solutions for "common" development scenarios to meet design objectives, which
are:



1)Stormwater Quality: Limiting the quantity of pollutants by adopting a best practices pollutant
load reduction approach, with consideration of the local climate.


2) Waterway Stability: Controlling the magnitude and duration of stormwater flows, to prevent
exacerbated in-stream erosion downstream of the development.


3) Frequent Flow: The hydraulic disturbance of in-stream ecosystems is similar to the pre-
development condition, which is achieved by capturing the initial portion of runoff from
impervious areas.

The     proposed              Peregian development will be in the Sunshine Coast Regional
                      Essence of
Council jurisdiction, which is in the North
                                            Co~st  climate-region of South East Queensland. The
proposed development type     is resi~ential land use, with a scenario of residential development
greater than 2 lots up to 20 lots. The  residential development scenario can include commercial
development of high-density, multiple dwelling buildings at’a scale of $; 12,500 m2. This
scenario applies to the "Essence of Peregian" development inclusive of the 6,970 m2
commercial node.                                                        ~




The site details of the Essence of Peregian ’Dev lopment are"presented on the annotated site
                                                                                             ’<

details plan (Appendix C), and summarized in,Table 10-1.

                                                                   ,j,f
                   Table 10-1: Site Details oftt\e Ess,ence of Pe!egian Development

            Site Detail                                                               Description
                                            The average grade is 3.6%, with a preferred flow pathway from
Existing Topography                         east to west across the development.

Existing Drainage                           There          are   no   significant existing drainages in the proposed
Characteristics                             development            area.


Proposed Discharge Points                   A proposed stormwater drainage has been designed for this
and Invert Levels                           development (refer to plan drawings in Appendix A).
                                            The surface and sub-surface soils of the proposed development
                                            area         include imported fill, silty-clay, silty-sand, and fine sand.
                                            The surface soils are acidic, with low nitrogen concentration and
Soils
                                            very low salinity. Acid sulphate soils may occur in the sub-
                                            surface, but these soils will not be excavated or disturbed
                                            because additional fill will be placed over them.




@2012 Simmonds & Bristow Pty LId                             Contrast Constructions                         J-1005-31 0   _
                                                                                                                              22 March 2012
1:ICLlENTFILESIContrast Constructionsl110B-155c   -
                                                      Essence of Peregian SCEP Stage 1 Updatel09_Output DocumentsI110B-155C_SWMP
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