1909-13367 SRA referral response approved docs

                         Figure 10 – 1% AEP Developed flood depths extract.
4.2.12 1 % Ae p R es ult s ( D ev elo pe d w ith bl oc k ag e )

The peak water level during the above event at reporting point 1 was 106.54m AHD. The peak water
level at point 2 is 105.36m AHD. Point 1 shows an increase of 0.02m compared to the developed case
without blockage. Point 2 shows an increase in peak water elevation of 0.15m compared to the
developed case without blockage.

The peak flow at flow line 10 was 44.17m3/s.
This is 2.69m3/s less than the existing case.
Sensitivity Case
A special blockage case has been run to determine the sensitivity of the model to blockage. For this
case items 3, 4, 5 and 6 have been considered 100% blocked. The result of this model run is a peak
water elevation of 107.93m AHD at point 1 and 105.42m AHD at point 2.

This event shows an increase of peak water elevation at point 1 of 1.41m at point 1 compared to the
developed model without blockage. This will still not affect the development property. At point 2 this
model shows an increase of 0.21m in peak water elevation.

This model is presented as a worst case scenario only is not considered to be a design event.
4.2.13 1 in 5 00 R e su lt s ( D ev elo pe d n o b lo ck ag e)

The peak water level during the above event at reporting point 1 was 106.63m AHD. The peak water
level at point 2 is 105.39m AHD. The developed case shows a decrease in peak water elevation of
0.03m at point 1. Point 2 also shows a decrease of 0.06m in peak water elevation.
The peak flow at flow line 10 was 51.90m3/s.




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S19-007                                 122 & 144 Myall St, Cooroy