2019-06-05 Special Meeting Minutes

SPECIAL MEETING MINUTES                                                            5 JUNE 2019


        b.   The detention tanks must be sized to ensure no increase in peak discharge from
             the site for all events from 63%AEP to 1% AEP inclusive.
        c.   The first application for Operational works for the development must include a
             Music Model prepared in accordance with the Water by Design Music Modelling
             Guidelines, and which demonstrates that the development layout proposed in the
             Operational Works application will achieve the State Planning Policy Water
             Quality Objectives of 80% Reduction in Total Suspended Solids, 60% Reduction
             in total Phosphorous, and 45% reduction in Total Nitrogen. The results of the
             MUSIC modelling must also demonstrate that the developed site will discharge
             less annual loads of Total Nitrogen, Phosphorous and Total Suspended Soils
             respectively compared to the pre-development scenario.
        d.   The pervious percentage of the development must be consistent with the
             pervious percentage derived from attached Simmonds & Bristow Drawing 1108-
             155C-01-02 Rev C (13 January 2012). RPEQ certification must be submitted to
             Council that states the pervious percentage of the final development is consistent
             with that derived from the Simmonds & Bristow Drawing.
        e.   The configuration of the stormwater quantity and quality components of the
             stormwater management system must be generally in accordance with Figure
             SW-1 (attached) unless otherwise agreed by Council.
        f.   The bioretention system must be formed with batters and not walls and include
             a minimum width of 5 metres.
        g.   Unless directed otherwise by Council, the detention tank will be covered.
        h.   The plan shall include detailed information in relation to the following aspects of
             the design of the bio-retention system:
             i.     calculations of underdrainage requirements for the bio-retention system;
             ii.    filter media composition requirements;
             iii.   a schedule which details how the construction, establishment, certification
                    and various inspections associated with each treatment measure relate to
                    other civil works;
             iv.    Where bioretention basins are used for stormwater quality treatment, the
                    design must be consistent with all aspects of the Water by Design (2014)
                    Bioretention Technical Design Guidelines Version 1.1) Healthy Waterways
                    Ltd Brisbane, including for free draining outlets to and from the bioretention
                    basins, and include completed copies of the design check and
                    summary contained within that document to confirm free draining outlets,
                    within reasonable construction tolerance capabilities are achieved; and
             v.     presentation of groundwater testing results which demonstrate that all parts
                    of the treatment measures are located above seasonal high groundwater
                    levels.
             A copy of the detailed civil drawings for the bio-retention system must be included
             as an appendix to the plan.
        i.   The plan must include a comprehensive Maintenance Plan for the detention tank
             and the bioretention system including the frequency of cleanout, methods of
             cleanout, and general maintenance. The plan will include the requirement for
             regular inspections and the keeping of records (to be maintained and made
             available to Council upon request). The plan is also to stipulate that all necessary
             improvements are required to be made immediately upon awareness of any
             deficiencies in the treatment measure/s. The detention tank is to be capped and
             trafficable.

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