Further information re Request to Change Approval MCU 132003.221132.8

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ELECTRONIC TRANSMISSION

  To:                 Stockland                                            CC:                                     Brent Thomas (BC)



  Attention:          Joshua Sandergeld                                    Date:                                  6 June 2012



   Fax No:            email                                                Document Ref:                           F B 15573 013.doc



   From:              Damian Cavanagh                                     No. of pages including                  2
                                                                          this one

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Dear Joshua


RE: DOONELLA NOOSA POLLUTANT EXPORT MODELLING


Brown Consulting recently requested an update of the pollutant export modelling which consolidates
the water quality work for the entire development and incorporates changes to the Stage C layout
due to the link road modifications.


Using plans provided by Brown Consulting which represents the Link Road revised estimates of
available stormwater treatment system sizes have been developed. These were updated within the
existing site MUSIC model. Generally the incorporation of the Link Road fully within the Stockland
site has resulted in there being a loss of over 800m2 available for storm water treatment. This is a
significant percentage of the total treatment area that was available for Stage C.

Performance of Site Stormwater Management System


Remodelling of the performance of the site (entire 65 ha development which includes the 34.5 ha
external buffer) is provided in Table 1.


  Table 1 Mean Annual Pollutant Loads                         -
                                                                  Base Case (Modelling Period 1/1/1998 -1/1/2002)

                                                                           Base Case
                                               Parameter
                                                                        (Forested Site)
                                              Flow (MUYr)                       426
                                               TSS (kg/yr)                    36,500
                                                TP (kg/yr)                      37.0
                                                TN (kg/yr)                      422




With the incorporation of stormwater quality controls in all stages the results are shown in Table 2.