Ltr-20190925-IR Response-Noosa Marketplace_FINAL (1)

Response to sub-item 44:
As stated in Specific Outcome 017 of the Noosaville Locality Code above, there are several criteria in
regards flooding and drainage matters with Council specifically interested in extreme local flooding
and the risk to employees or visitors to the site.
The above matters have been addressed in coordination with inputs from Cardno – refer Appendix F.
In summary, the mapping for the probable maximum flood (PMF) and 1% AEP blockage scenario
indicates that:

•     The site remains accessible during the 1% AEP extreme (100% blockage) event. The depths are
      within the allowable depth recognised as acceptable by the Queensland Urban Drainage Manual;

•     The depth of flooding in Hofmann Drive at the main eastern entrance during the extreme 1% AEP
      event, is currently 153 mm. This is 10 mm less in the developed scenario for the 1% AEP event,
      and thus is improved;

•     The depth of flooding in Hofmann Drive at the southern entrance during the extreme 1% AEP
      event, is currently 158 mm. This is 47 mm less in the developed scenario for the 1% AEP event,
      and thus is improved;

•     Due to the upstream catchments being fully developed/impervious there is a negligible chance of
      flows onto the site increasing;

•     Peak flood depths will be for relatively short durations of 15 to 20 minutes, with the peak being
      less than 5 minutes of the overall duration;

•     In the PMF event the site will be accessible by emergency vehicles, for which a depth of 500mm is
      adopted. The depths are well below these levels; and

•     The risk of damage to property on the site is avoided or minimised as far as practicable.
As a commercial site, the proposed land uses will have limited vulnerable persons, and the number of
persons on site can be managed through typical emergency response plans for the respective
buildings in line with normal evacuation protocols. Mapping for the PMF shows that there is minimal
risk to persons during an extreme event with site access being maintained for all except small vehicles
and no inundation to the building footprint or carpark areas.

Therefore, it is considered that all matters in points (a) to (e) have been fully addressed and safety of
people at the site is not considered a significant risk.




    Ltr-20190925-IR Response-Noosa Marketplace_FINAL                                                      83