1909-13367 SRA referral response approved docs

                                        Figure 6 – 2D Flow Lines



1D Blockage

1D blockage levels have been determined in accordance with ARR 2016 revision project 11.

Blockage factors have been applied to specific 1D elements to determine the effect on flooding. A risk
analysis has been conducted for critical elements to determine the likely level of blockage for each
scenario.

This guideline relies on the determination of the likely debris size as well as the potential for debris to
reach the structure in question. It is preferred that evidence of debris from previous storms be used for
this analysis, however there was no evidence available at the time of this report. Additionally, the nature
of debris in large events can vary greatly from event to event as the time between events can affect the
amount of available debris.

Without data from site for this analysis the determination of the likely size of debris has been based on
aerial imagery and site visits.

Table 5 and 6 below summarises the risk assessment that has been carried out in accordance with
AR&R project 11 for each 1D element of interest. Please see Appendix BF for the locations of each
element.




                                               Flood Study                                              18
S19-007                                 122 & 144 Myall St, Cooroy