23616DA - Change to Existing Approval [As Published] · 132003.221132.6

                                                                                                 23616DA


      47.2. Specify appropriate remedial treatments.
48.   The residential precincts shall be designed to incorporate, within their boundaries all the
      necessary sediment and erosion control devices.
Stormwater Management Plan
49.   A Stormwater Management Plan for the site including revegetation and remediation of all water
      treatment areas including swales and bioretention systems shall be prepared to the reasonable
      satisfaction of Council. The Stormwater Management Plan shall be generally in accordance
      with WBM’s Report of 30/3/03.
50.   The developer shall comply with the Stormwater Management Plan and the operational stage
      components of the Stormwater Management Plan shall be referenced in the community
      management statements for all group housing developments over the site.
51.   Key water quality objectives to be reflected in the Stormwater Management Plan are the
      protection of aquatic ecosystems in the site gullies, Cranks Creek and the eastern creek and
      within the receiving waters of Lake Doonella and the Noosa River, as well as primary contact
      recreational standards within the receiving waters. Appropriate water quality standards to be
      adopted are those as specified by Brisbane City Council (in conjunction with the South East
      Queensland Regional Water Quality Management Strategy).
52.   Stormwater Management - MUSIC modelling; Prior to the completion of the final stormwater
      management plan and the civil design drawings for operational works, any stormwater
      management assessments utilising the CRC for catchment hydrology's MUSIC modelling
      system must be corrected for a possible error in the assessment of bio-retention system
      efficiencies and performance in removal of nutrients, as recently notified by the CRC. Empirical
      calculations such as the Brisbane City Council spreadsheet method shall be use to adjust the
      MUSIC model and to demonstrate that realistic removal efficiencies are being used.
      Alternatively, once a 'patch' is available from the CRC, this corrected version of the software can
      be used, but, again, cross checking with empirical calculations is required. The error in the
      bioretention routine will result in the need for additional water quality treatment measures. Initial
      assessments indicate that MUSIC is over predicting removal by as much as twice what should
      be occurring.’
      If these checks indicate that the bioretention devices require enlarging, the applicant shall
      remove lots, if necessary, from the development in order to accommodate the devices without
      affecting the public and private open space areas. If the system requires amending, an
      amended report is to be submitted to Council for checking.
53.   Monthly reports on monitoring, incidents, corrective action and plan updates are required to be
      submitted to Council. These reports are to be submitted in a form acceptable to Council and
      are to highlight any non-standard results.
54.   Any stormwater outlet to the gullies on the site are to be stabilised with appropriate energy
      dissipation and local armouring. Regular monitoring of creek erosion is required with
      appropriate corrective action specified to ensure a stable creek system. All work to be
      undertaken to minimise impacts on the Environmental Values of the creek system.
55.   The residential precincts shall be designed to incorporate, within their boundaries, all the
      necessary stormwater and water quality control devices associated with the development.
56.   The applicant will ensure that all necessary overland flowpaths for Q100 events are provided on
      site and covered by an easement where they traverse private property.
Water Quality
57.   The Developer is to install water quality control devices generally in accordance with the
      Stormwater Management Plan. Detailed staging plans and specifications, based on and
      generally in accordance with the Plan are to be prepared and submitted (after consultation with
      officers of the Council) with the relevant applications for operational works.


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