080624 2383-01 FINAL Engineering Report for DA.pdf [As Published] · 132008.1128

BLUE CARE SUNRISE BEACH
ENGINEERING REPORT FOR DEVELOPMENT APPLICATION




    2.5.2          Model Parameters

    The land-use parameters for the source nodes in the MUSIC model were adjusted to
    match the values given in Table 2.3 based on the BCC Guidelines (BCC, 2003).

    Table 2.3, MUSIC Source Node Catchment Parameters
           Parameter                                                                        MUSIC Input
                                                                                         Urban Residential
           Impervious                    Rainfall threshold (mm/day)                            1.0
           Area
           Pervious                      Soil Storage Capacity (mm)                             400
           Area                          Field capacity (mm)                                    200
                                         Infiltration capacity coefficient – a                  50
                                         Infiltration capacity exponent – b                     1.0
           Groundwater                   Daily recharge rate (%)                                25.0
                                         Daily drainage rate (%)                                25

    The pollutant export parameters for the MUSIC model were adjusted to be consistent
    with data quoted in BCC Guidelines (Table 2.4, BCC, 2003) and the Gold Coast City
    Council (GCCC) MUSIC Guidelines (Table 7, GCCC, 2006). The source node input
    data for the land uses are shown in Table 2.4.

    Table 2.4, Source Node Event Mean Concentrations and Standard Deviations
       Land Use Type                Parameter                TSS                    TP               TN
         for MUSIC                                       Log10 (mg/L)           Log10 (mg/L)     Log10 (mg/L)
       Source Nodes                                     Base Storm            Base      Storm   Base     Storm
                                                        Flow     Flow         Flow      Flow    Flow     Flow
      Internal (Urban)              Mean                1.00     2.18         -0.97     -0.47   0.20      0.26
                                    Std Deviation       0.34     0.39          0.31      0.31   0.20      0.23
      Roof Areas                    Mean                1.00      1.3         -0.97     -0.89   0.20      0.26
                                    Std Deviation       1.34     0.39          0.31      0.31   0.20      0.23

    The land type ‘split’ was carried out in accordance with the GCCC MUSIC Guidelines to
    effectively account for rainwater harvesting from the roof areas within the model. For
    the initial modelling, the roof node was modelled as being 100% impervious, with the
    urban node modelled as 26% impervious.

    2.5.3          Pollutant Removal Parameters

    Gross Pollutant Trap

    The adopted pollutant removal parameters for the GPT are outlined in Table 2.5. A high
    flow bypass of 0.75m3/s was applied, based on the potential use of a Rocla CL750 unit.
    It is noted that the manufacturer specification provides for a higher removal capacity for
    TSS than shown in the Table 2.5.




Blue Care Property Development Unit                             Version 1.1                                  24 June 2008
2008 06 24 2383-01 Engineering Report for DA               Commercial in Confidence                                Page 8