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

The proposed development does not directly, indirectly or cumulatively significantly alter the flood
characteristics external to the site for all flood events up to and including the defined flood event.

ISSUE 12: LOCAL FLOOD IMPACTS
The local flood impact maps provided with the IWMP demonstrate that flood depths external to the site
are predicted to increase as a result of the proposal. This is in conflict with Specific Outcome O17 of
the Noosaville Locality Code and Specific Outcome O33 of the Business Uses Code.
Information Required
      43. Provide revised proposed plans and flood impact mapping which demonstrates compliance
          with Specific Outcome O17 of the Noosaville Locality Code and Specific Outcome O33 of the
          Business Uses Code and specifically demonstrates no flood impacts external to the
          development site boundary.
Response to sub-item 43:
On review of Specific Outcome O33 of the Business Uses Code it is suggested that these matters,
including water quality, are better addressed though response to Issue 9, sub-item 39 above.
In relation to Specific Outcome O17 of the Noosaville Locality Code, it states:
      Flooding and drainage
      O17 Buildings and other works are designed and sited to—
          a)   provide flood free access to premises and flood free habitable areas;
          b)   allow only minor, short term and infrequent flooding of non-habitable areas;
          c)   ensure carparking areas can be adequately drained;
          d)   ensure drainage does not adversely impact upon other premises; and
          e)   ensure filling or excavation does not adversely impact upon other premises by—
                 i. causing ponding on the site or nearby land;
                 ii. increasing flooding, which adversely affects the safety or use of any land upstream
                      and downstream; and (emphasis added)
                 iii. adversely affecting the flow of water in any overland flow path.
These matters have been addressed in coordination with inputs from Cardno. The following
attachments include the full response:

•     Appendix H in relation to the hydrology aspects in Issues 10 & 11, sub-items 40-44

•     In reviewing the flood data, the applicant recognizes that minor increases in flooding occur
      upstream and downstream of the site – See Figure 48 below.

•     The updated mapping for the increase in flooding impacts indicates that:

      −    Areas where impacts are recorded adjacent to Eenie Creek Road are inundated for all events
           in the existing case, with the proposed development forming a partial blockage of the existing
           flow path and hence slightly increases the peak flood levels within the Eenie Creek Road
           reserve during events equal or greater than a 10% AEP. It is noted that during the existing
           case 1% AEP, flood depths of up to 1 metre already exist at this location with the existing
           topography acting as a detention basin;




    Ltr-20190925-IR Response-Noosa Marketplace_FINAL                                                       80