2008/0169 Response to information request - 71 Seaview Tce Sunshine Beach · 132008.169

                                              Figure 3 - External Catchment Plan

3.3     CO-EFFICIENT OF RUNOFF

To be conservative the adjoining properties to the west were assumed to have a fraction impervious of 0.60 from
aerial photography. A C10 value of 0.82 was assumed from Table 4.05.3 (a), QUDM, 2"d Edition, 2007.

3.4     TIME OF CONCENTRATION

Due to the steep grade of the adjoining allotments the time of concentration of the external catchment was
assumed to be 5 minutes from Table 4.06.1, QUDM, 2Edition, 2007.


3.5     RAINFALL INTENSITIES

The rainfall intensities for the catchment discharging to the western boundary of the site were determined from
the IFD chart for the Noosa Region calculated from AR&R, 1987.
                                                    Table 1 - Rainfall Intensities

       Time of Concentration         1 year          2 year       5 year        10 year        20 year        50 year       100 year
                  (mins)            (mm/hr)         (mm/hr)     (mm/hr)         (mm/hr)        (mm/hr)        (mm/hr)       (mm/hr)

                   5.0                 129      I      163          201            223              253   I     291     I     321

3.6     FLOWS (UNMITIGATED)

The flow discharging to the western boundary of the site is shown below for a range of storm events.


                                                    Table 2 - Flows (Unmitigated)
      Catchment      QI (m3/s)     Q2 (m3/s)        Q5 (m3/s)    Q10 (m3/s)         Q20 (m3/s) fQ50(m3/s)               Q100 (m3/s)

       External            0.087     0.116            0.160           0.187              0.223            0.281             0.323




 SITE BASED STORMWATER MANAGEMENT PLAN - Revision D             ! Se-view Terrace. Sunshine Beach