MCU21.0117 OPW21.0199-Applicant's Response to Council's IR · MCU21/0117

        demonstrate that there is sufficient capacity within the internal drainage network at the discharge
        point and in the table drain along Pearl Street. This takes into account the upstream and downstream
        catchments draining to the table drain, to determine the maximum discharge rates from the
        development with minimal impacts to upstream or downstream properties for storms up to the 1%
        AEP. Please refer to the updated Stormwater Engineering Report for details.


Information Required by Council

6. Please provide MUSIC modelling and updated engineering plans which demonstrate compliance with PO6
and AO6.2 of the Water Quality and Drainage Code.


Applicant’s Response

6. Refer to Recor’s response to the Information Request enclosed within Attachment 4. An extract from the
response is provided below:

        The site and the treatment train proposed for the development has been modelled in MUSIC in
        accordance with the Water by Design MUSIC Modelling Guidelines for Southeast Queensland. The
        results demonstrate that the site achieves compliance with PO6 and AO6.2, being reductions in
        excess of 90% of gross pollutants, 80% of total suspended solids, 60% total phosphorous and 45%
        total nitrogen at the discharge point. Please refer to the updated Stormwater Engineering Report for
        further details.


Information Required by Council

7. Is the1200x600 grated inlet outside POD B a sag gully (this is unclear due to limited design levels)? If it is a
sag, demonstrate that the minimum 300mm freeboard required by AS3500 to the adjacent building floor
levels is achieved.


Applicant’s Response

7. Refer to Recor’s response to the Information Request enclosed within Attachment 4. An extract from the
response is provided below:

        This pit has been removed, however pits in the driveway area are on grade, and within the
        bioretention areas, a minimum of 300mm freeboard to the adjacent building floor levels is achieved.


Information Required by Council

8. Provide calculations/HGL analysis demonstrating that the surcharge pit outlet from the site will not
surcharge the upstream pits during the design event due to the limited grade.



                                                                      PO Box 1818         07 5474 3873
                                                                      Noosa Heads         [email protected]
                                                                      QLD 4567            rgstrategic.com.au