Stormwater Management Plan · MCU15/0122

                                                                                          15099 - SBSMP/3
                                                                                                   Page 9




5.5 Peak Flows
Refer to Table 5-3 for a summary of the predicted minor and major discharge rates for pre- and
post-development conditions and Appendix F for the Rational Method calculations.

                               Table 5-3 – Pre and Post-Development Peak Flows

                             Property State               Q10 (m3/s)        Q100 (m3/s)

                           Pre-development                  0.161                0.279
                           Post-development                 0.230                0.386


It is evident that there will be an increase between the pre-development and post-development
peak discharge flow rates. On-site detention will therefore be required to mitigate the
increased discharge flow rates to ensure pre-development flow rates can be achieved.


5.6 On-Site Detention Analysis
XP-RAFTS has been used to model the peak discharges from the site under both existing (pre-
development) and proposed (post-development) conditions, and to determine the sizing
requirements of the detention basin as outlined in Section 5.05.2 of the QUDM.

5.6.1 Pre-Development
Figure 5-1 shows the XP-Rafts model used to represent the pre-development site conditions and
Table 5.4 summarises the input parameters used in the model for the pre-development site
scenario.




                             Figure 5-1 –XP-RAFTS Pre-development Model




Site Based Stormwater Management Plan
Proposed Medical Development at Cnr Val Crescent & Goodchap Street, Noosaville