5179Flood Report_REV_3

                                                                                             Callaghan & Toth




2.0       FLOOD IMMUNITY

The Year 2100 1%AEP flood levels across the north-east corner of the site have been abstracted from a
flood study undertaken by Brisbane Stormwater Management Pty Ltd for the adjoining Erindale
Development in 2014. The relevant flood levels are 100.34 m AHD across the eastern (upstream)
boundary of the site and 99.94 m AHD across the northern (downstream) boundary of the site. Those
Year 2100 1%AEP flood levels are marked on the preceding Figure 1.3 and on Figures 3.2 and 3.3
hereafter, together with the inferred Year 2100 1%AEP flood boundary between those two levels.

The proposed lots are seen, in comparison to the 0.5 metre contours on Figure 3.3, to be at least a metre
above the flood profile and will therefore be immune to 100-year flooding, even with a 20% impost on the
design rainfalls for future climate change.

The proposed stormwater detention facilities are also seen on Figures 1.3 and 3.3 to be outside the Year
2100 1% AEP flood boundary and will therefore have no impact on the storage-routing capacity of the
floodway.




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2035 2 Pearsons Road – Flood Study – Revision 3                                      April 2021