RFI - 075-028 SWMP Report

have a high flow discharge via a 100mm diameter orifice at a height 1.444m from the reuse base. This would
allow a total storage of 5KL which exceeds the 4.6KL volume requirement.
This tank is shown in Figure 5 (and detailed in Bax Engineering plan 075-028-SK03 as part of Appendix A).




Figure 5 – Proposed Slimline Detention Tank



                              Peak Flow at Outlet

However, the catchment flowing to the eastern outlet (LPD1) has increased and peak volume will need to be
maintained. With the inclusion of the detention system, post development flows have been analysed for the
outlet location. Modelling of the system was undertaken using XPSWMM for the pre and post development
to ensure no increase. The peak duration and rainfall temporal pattern was nominated as the 15min and Storm
02 for the 1%AEP event. The pre development and post development (unmitigated and mitigated) are
provided in Table F. This demonstrates that the incorporation of the detention system will show no increase
in peak flows.



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