Development Application Part 2 - Environmental & Stormwater Management Plans · OPW11/0335

8.         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 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 Essence of Peregian development will be in the Sunshine Coast Regional
Council jurisdiction, which is in the North Coast climate region of South East Queensland. The
proposed development type is residential 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 6,970 m2 commercial node of the "Essence of Peregian" Stage 1
development.

The site details of the Essence of Peregian Development are presented on the annotated site
details plan (Appendix C), and summarized in Table 8.



                      Table 8: Site Details of the Essence of Peregian Development
             Site Detail                                                               Description
Existing topography                           The average grade is 12% across the Stage 1 development area and 3 6%
                                              across the entire development (Stage 1, Stage 2 & Stage 3), with a preferred
                                              flow pathway from east to west across the development.

Existing Drainage Characteristics             There are no significant existing drainages in the proposed development area.
Proposed Discharge Points and                 A proposed stormwater drainage has been designed for this development
Invert Levels                                 (refer to plan drawings in Appendix A).
Soils                                         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 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.




02011 Simmonds & Bristow Pty Ltd              Pacific Plumbing - Scanlon Property Group Pty Ltd                       J-1109-155 - 8 September 2011
1 CLIENTFILES\Contrast Consimcbons11109-155c - Essence of Peregian SCEP Stage I Update\09_Ontput OocumenI \J.I I09-155c_SMP Scanbn Property
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