Appendix C - Flood Report_Sept2020

                                                                                                         Callaghan & Toth




2.0       FLOOD IMMUNITY
The 100 year 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 100.19 m AHD across the eastern (upstream) boundary of the site and 99.85 m AHD across
the northern (downstream) boundary of the site. Those flood levels are marked on Figures 3.2 and 3.3 hereafter,
together with the inferred 100 year 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 1.5 metre above
the flood profile and should therefore be immune to 100 year flooding, even with a 20% impost on the design rainfalls
for future climate change.

The only intrusion of the development into the 100 year floodway is seen to be a small part of the outer batter of the
proposed detention basin. The loss in 100 year flood storage as a result of this intrusion is estimated to be about 9
cubic metres, which should have practically no impact on the 100 year flood profile.




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2035 2 Pearsons Road – Flood Study                                                           September 2020