Appendix B - Biome Consulting Response

                                    INFORMATION REQUEST RESPONSE

                              DEVELOPMENT APPLICATION MCU17/0551
                                  19 & 20 Trading Post Road, COOROY

Request Item 4.

Issue:
Previous applications have demonstrated that 75 m2 of filter media needed to be allocated for
bioretention systems to achieve water quality reduction targets as required by the Water Sensitive
Design Code of the Noosa Plan and State Planning Policy for the overall development. This filter
media areas was based of impervious areas detailed in Appendix F of the provided stormwater
management plan

    4    Demonstrate that the road, ground and roof areas proposed in the application is consistent
         with the impervious and pervious areas detailed in Appendix F of the Stormwater
         Management Plan to achieve pollutant reduction targets consistent with the State Planning
         Policy

Response

The road, ground and roof areas of the developed site and the impervious fractions of each surface
type have been independently estimated by BIOME Consulting. Table 1 summarises the sub-
catchment characteristics.

                                Table 1 MUSIC Sub-Catchment Areas
                                                                                        Area           Total Impervious
   Catchment ID                           Land Use
                                                                                        (ha)                  (%)

                                  Urban Residential - Road                          0.163                       70
                                   Urban Residential - Roof                         0.241                       100
         D3
                               Urban Residential - Ground Level                     0.122                       50
                                          Total (ha)                                0.526                        -


The sub-catchment delineation is presented in Figure 1 and DWG-210 – Attachment A. It was
assumed that a typical lot will have a roof area comprising 75% of the total lot, based upon aerial
photography (Google Earth, 31 August 2017) showing existing lot and roof areas within earlier stages
of the development.

The sub-catchment areas defined by BIOME Consulting are consistent with those shown within the
submitted Stormwater Management Plan (SWMP) authored by Calibre Consulting, with only minor
variations between the areas and assumed impervious fractions.

To confirm that the previously determined bioretention filter area (75 m 2) will meet with the minimum
mean annual load-based reductions, a catchment model was executed using MUSIC v6. In
accordance with the State Planning Policy for Healthy Waters and the Queensland Water Quality
Guidelines (2009), the target pollutant reductions are 80% for Total Suspended Sediment (TSS); 60%
for Total Phosphorus (TP), 45% for Total Nitrogen (TN), and 90% for Gross Pollutants (GP).


BIOME Consulting Pty Ltd
                                  M: 0415 935 222      E: [email protected]     ABN: 86 166 087 476         Page 1
PO Box 3469, Australia Fair
Southport QLD 4215