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

Development details (site layout, sub-catchments, conceptual earthworks and conceptual
drainage) are provided as plan drawings in Appendix A (drawing numbers J-1005-310-01 to
05). Specifications of the site layout (roof area, balance area) are given in Appendix B. The
south sub-catchment (drawing J-1005-310-07 & J-1005-310-07b) will feature a designed
treatment train that flows from the Stage 1 development toward the Constructed Wetland
System and the receiving node of the receiving waters next to the Noosa National Park.

The Solutions state minimum sizes of Rainwater Tanks, Bio-retention systems and Constructed
Wetlands that are required to meet the Queensland Development Code Mandatory Part 4.2 and
4.3, and the stormwater quality objectives outlined in the Best Practice Environmental
Guidelines - Urban Stormwater. The stated dimensions proposed for the Essence of Peregian
development are listed in Table 9.



     Table 9: Dimensions of Rainwater Tanks and WSUD Deemed to Comply Solutions
                                                      Deemed to Comply
  Deemed to Comply Solution                                                                              Development size
                                                        Requirement
 Rainwater tank for attached                    Old Development Code MP 4.3                  1 x 1 flOkl - -ornrnernal building
 dwellings in the Sunshine Coast                requiresl-5 kL per required
 Regional Council (North Coast)                 pedestal in commercial building
 region:                                        with a class 3 code (i.e. motels
                                                or boarding houses that
                                                unrelated people co-habit).

 Bio-retention System Filter Media              1.1 %                                       Bio-retention South = 0.6
 Area (% of catchment area):

 Constructed Wetland Macrophyte                 6%.                                         Wetland C = 3.2 %
 Zone Area (% of catchment area):


The Rainwater Tank is sized appropriately for the commercial building, with ample volume to
satisfy the non-potable water use requirement of the Qid Development Code MP 4.3. The
surface areas represented by the Bio-retention Trenches (0.6 % of the catchment area) and the
Constructed Wetland System (3.2 % of the catchment area) are less than the WSUD Deemed
to Comply Solutions (1.1 % and 6 % respectively).

It is possible to design a stormwater treatment train outside the prescribed parameters,
provided that the Best Practice Environmental Management Guidelines - Urban Stormwater and
the planning requirements of the assessment authority are followed.    A carefully designed
stormwater treatment train has been proposed by the Stormwater Management Plan, and has
been supported by detailed MUSIC modelling (Section 5).

In summary, the Environmental Impact Assessment indicated that the proposed Essence of
Peregian Stage 1 development will have negligible consequences resulting from total
suspended solids, total nitrogen and total phosphorus entering Noosa National Park.           The
treatment train for the SWP has been designed to minimise the effects of rainfall and
stormwater erosion of the landscape, retain rainwater collected on roofs and hard surfaces for
irrigation and commercial use, and direct remaining overflow through Bio-retention Trenches
and the Constructed Wetland System. Detailed MUSIC modelling identified that the proposed
development will achieve the required water quality objectives (Appendix B). Suspended solids
and total nutrients will be removed early in the treatment sequence (Appendix B). It is predicted
that the maximum concentrations of pollutants in stormwater during extreme events (Appendix
B) will be substantially less than concentrations presently measured in stormwater entering the
terminal wetland from the existing caravan park site (Table 3Errorl Reference source not
found.)




©2011 Simmonds & Bristow Ply Ltd             Pacific Plumbing - Scanlon Property Group Pty Ltd                      J-1 109-155 - 8 September 2011
1:1CUENTFILES1Conlrasl ContNC110n511109-1SSc -Essence of Peregian SCEP Stage 1 Update109 Oulpul Documen1sU-1109-155c_SMP_Scan1on Property
Group SECP_ge_la_l10905.doc                                                                                                       Page 13 of 21