Appendix B - Amended Biome Consulting Response

 Item    Brief Summary of Item                       Response to Item
 64      Demonstrate the Stormwater Quality          Section 4 in this report provides stormwater quality analysis, outlining
         Management Strategy meets Water             the proposed Stormwater Quality Management Strategy, which
         Quality Objectives as per the SPP, 2014.    demonstrates compliance with WQO’s for the site. Discussion of the
                                                     treatment of external catchment runoff and modelling methodology is
                                                     provided in Section 4.
 65.1    Letter from Water By Design or eWater       In the proposed modelling (refer to Section 4 in this report), there has
         where MUSIC modelling deviates from         been no deviation from specifications provided in the MUSIC Modelling
         MUSIC Modelling Guidelines (2010).          Guidelines (2010). Therefore, a letter is not required. As per previous
                                                     correspondence with Council, the pond node has not been modelled in
                                                     MUSIC. This is a conservative assumption considering that the pond
                                                     will capture suspended solids through a process of sedimentation and
                                                     provide some reduction of nutrients.
 65.2    Contingency plan with costs to be           A contingency plan has been provided in Appendix A of the SMCMP
         provided to Council. Stormwater runoff      Report. Stormwater runoff is to receive primary treatment from
         from roads and car parking areas to be      proprietary GPT’s that can remove grease and oil, and tertiary
         pre-treated for grease and oil.             treatment from Bioretention Basins before discharge into the Pond.
                                                     Note that all areas likely to generate significant amounts of grease and
                                                     oil will be pre-treated by GPT’s. Since the catchment to the Northern
                                                     Bioretention Basin is smaller than 5ha and does not contain significant
                                                     areas of car parking or road, a sediment forebay is proposed.
 66      Stormwater Quality Treatment Devices to     Bioretention Basins and the Pond have been designed accordingly.
         be designed in accordance with Healthy      Details are provided in Section 2.1 and Section 3.1 of the SMCMP
         Waterway and Water By Design                Report.
         guidelines.
 67      Stormwater design and maintenance           The criteria and framework for design, construction and operational
         strategy in accordance with Council’s       maintenance for stormwater devices is in accordance with the
         approved Framework Letter Report (No.       Framework Letter Report approved by Council. Refer to the SMCMP
         B14158.W.07L dated 8 October 2015)          Report for details.
 68      The SMCMP Report to be in accordance        The SMCMP Report has been written in accordance with this approved
         with Council’s approved Framework           document.
         Letter Report (No. B14158.W.07L dated
         8 October 2015)
 69      Owner responsibility for construction,      This condition is stipulated in this report.
         maintenance and repair costs of
         stormwater management devices.
 70      Calculations to demonstrate runoff to       Energy dissipaters (i.e. rock scour protection) have been provided at
         northern swale within the site will not     drainage outlets into the northern site swale. Energy Dissipation
         cause scour.                                Calculations and Manning’s Sections (comparing existing and
                                                     developed conditions of the swale) are provided in Appendix A of the
                                                     SMCMP Report.
 71      Any waters captured to be plumbed and       The capture of all water for external uses was not proposed as part
         used for external or non-potable uses.      of the previously approved MCU submission. The capture of all
                                                     water on site is not required for the site to meet both Stormwater
                                                     Quality and Quantity Objectives to be achieved and is therefore not
                                                     proposed or required.
 72      Developed peak flows from the site          As per response to Condition 63, Section 3.2.6 of this report
         during the 63% AEP storm event to be        demonstrates that proposed detention basins are adequate in reducing
         reduced back to or below existing levels.   peak flows to meet this condition.
 73      Performance bond to be provided to          Monitoring and maintenance costs are detailed in Appendix A of the
         Council equivalent to 150% of the value     SMCMP Report. A performance bond will be provided to Council for the
         of monitoring and maintenance of the        first 5 years of full operation of the pond.
         water bodies.

        Since the MCU Approval Conditions, Council have issued Stage 2 Operational Works Approval Conditions.
        Responses to this latest approval are summarised in Letter Report No. 16-001014.02L.ms.cm.docx dated
        January 2017




16-001014-01B | STORMWATER MANAGEMENT PLAN                        COOROY RETIREMENT COMMUNITY, TRADING POST
(SWMP) | PALM LAKE RESORTS                                                                    ROAD, COOROY                      |4