MCU14/0106 & OPW15/0001 Information Request Response Report (absent appendices)

                                                                                                        Noosa Civic Expansion
                          28 Eenie Creek Road, Noosaville and parts of the road reserves of Hofmann Drive and Walter Hay Drive



                 by the Environmental Protection (Water) Policy 2009 Noosa River environmental
                 values and water quality objectives Basin No. 140 (part), including Kin Kin Creek,
                 Teewah coastal creeks, Lakes Cooroibah, Cootharaba, Doonella and Weyba July
                 2010.”
            RESPONSE
            This item of the information request has been confirmed with Noosa Shire Council as being made
            on the assumption that the scale of the proposed development exceeds that provided for in The
            Noosa Plan.
            It is noted that Noosa Shire Council does not have an eSource model for the catchment, but is
            currently in the process of preparing one. Such a model is not expected for another six (6)
            months.
            Assuming Precinct E1 of the SBC is developed with a three storey commercial building up to the
            maximum plot ratio contemplated for the precinct by The Noosa Plan, it would result in a
            maximum GFA of 2.4ha and require 1,200 cars. The total surface area of the development would
            be approximately 3.6ha, comprising 1.2ha of roof area and 2.4ha of car parking, and 0.4ha of
            green space.
            In contrast, the proposed development comprises 2.1ha of roof area, 1.5ha of car parking and
            0.4ha of green space.
            The development proposal is comparable to the form of development contemplated by The
            Noosa Plan, such that an eSource model is not considered to be required to address the
            suggestion that the scale of the proposed development exceeds that provided for in The Noosa
            Plan.
            Further, Cardno does not consider it necessary to undertake catchment source modelling for the
            development application. The water quality reduction targets are defined as part of the State
            Development Assessment Provisions, and have been shown to be achieved on site using MUSIC
            modelling.
            For more information, please refer to Appendix E – Stormwater Management Plan to this
            report.

5.6         Water Quantity
            “The concept of the use of the car parks and bioretention basins is considered acceptable
            means for providing flood attenuation but the quantum of detention may need to be larger than
            that allowed for.

            Information Required:
            55   Amended WBNM model and proposal plans, and potentially a hydraulic plan, to
                 demonstrate the runoff from the development can achieve the required attenuation
                 for the proposed development layout. In particular, the following needs to be
                 addressed:
                 (a) Catchment Set-up - The WBNM model has assumed an initial loss of 7.5mm,
                     typically 15mm is more appropriate for existing conditions.
                 (b) Detention Basins:
                    (i)    Peak flood levels in the car park exceeds the QUDM limit of 300mm for a
                           major flood, it’s noted in minor flood peak levels exceed this limit and is
                           typically over 500mm;
                    (ii) Peak levels in the Bioretention exceeds the QUDM limit of 1.2m for a 20yr
                         ARI flood, this level should be reduced.”




June 2015                                             Cardno HRP                                                           33