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

S.         STORMWATER MANAGEMENT PLAN

Plans provided in Appendix A show the location of key features of the Essence of Peregian
SWP that are relevant to Stage 1 of the development. These plans are:

J-1005-310-01 - Rev 2, Nov. 2010, Site Location;
J-1005-310-02 - Rev 2, Dec 2010, Proposed Bio-retention Basins and Wetlands;
J-1005-310-04 - Rev 1, Dec 2010, Bio-retention Basin and Wetland Layout;
J-1005-310-05 - Rev 2, Dec 2010, Bio-retention Basin and Wetland Cross Section A-A;
J-1005-310-06 - rev 1, Nov. 2010, Stormwater Treatment Train (Operation Phase);
J-1005-310-07 - Rev 1, Nov 2010, Stormwater Management Control Areas;
J-1 105-310-07b - Rev 1 Sep 2011, Stormwater Management Control Areas Stage 1 Only;

Plans that are directly relevant to the Stage 1 development are listed in Appendix A as follows:

The Site Location (Drawing 01) and the Bio-retention Basin and Wetlands Plan (Drawing 02)
show site boundaries of the Essence of Peregian in relation to the Noosa National Park to the
west, and urban development to the north, south and east.

The Essence of Peregian development will install water sensitive urban design features to
ensure that water quality entering the Noosa National Park meets the required guideline
concentrations (Table 1). These features will capture and hold stormwater in a Rainwater Tank
and on the land, the stored rainwater will be used for domestic purposes within the commercial
complex, or for irrigating the gardens to ensure stable ground cover. Stable ground cover is an
important feature of erosion risk management.

Stormwater will be piped directly into a Bio-retention Trench (Drawing 03, Drawing 04) which is
a depression storage designed to infiltrate stormwater into the ground. This features will be
installed within fill platforms placed over the existing landscape, hence acid sulphate soils will
not be excavated and disturbed. The fill platforms in the design plans have a minimum height
of 3.3 m, which is above the 100 year ARI flood level identified for the nearby Lake Weyba (RL
2.05m AHD) (Brown, 2007). After passing through the Bio-retention trench, stormwater will flow
through a constructed wetland system (Drawing 05).

Overland flow will be diverted, via catch drains, into the Bio-retention trench (Drawing 06,
Drawing 07) for treatment by the Bio-retention trenches and constructed wetlands.

Overflow from the rainwater catch tank will be piped directly to the constructed wetland.

The development site does not fall within the flood hazard area nominated by the Noosa
Council (Brown, 2007). The stormwater treatment train is designed to accommodate the most
intense stormwater event encountered during a 5 year interval described by the ARI records
(202 mm/hour over a 5 minute period) (Australian Government, Bureau of Meteorology).

           5.1.        MANAGEMENT OF OVERLAND FLOW OF STORMWATER

           This sub-section describes the treatment train (Drawings 02, 06 and 07) used to
           manage stomiwater flowing through the Essence of Peregian development.           The
           treatment train is designed to keep stormwater within the landscape of the proposed
           development site. There are three treatment units in the design treatment train:




02011 Simmonds & Bristow Pty Ltd                Pacific Plumbing - Scanlon Property Group Pty Ltd                      J-1109-155 - 8 September 2011
1 `CLIENTFILES'Cont,st ConstrucbonsU 109.155c - Essence of Peregan SCEP Stage I Updatet09_0utpne Docun,enlsU-1109-155c_ShW_SCanbn PTopedy
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