response to information request - pomona subdivision 19.11.2021

   14. Provide RPEQ written certification, certifying that the proposed filling
       works and retaining structures, will not cause a worsening of stormwater
       conditions by adversely altering stormwater drainage characteristics
       external to the site, including, but not limited to:
          a. additional ponding on neighbouring properties;
          b. increased runoff onto neighbouring properties;
          c. redirect overland flows.

TODs plans have been designed in coordination with Peak Urban’s Stormwater
Management Plan, which conclude:

   It has been demonstrated that non-worsening of peak flows has been achieved
   to the discharge point for events up to the 10% AEP event (refer Table 2-7).
   The results show that there is non-worsening for events up the 5% AEP, with a
   minor increase noted in the larger events. The intent of sizing the detention
   basin is to mitigate flows up to the 10% AEP storm event to ensure non-
   worsening of discharges into the downstream flow path. In larger events, flows
   from the site will start to sheet flow across the rear of the site to Cooroora Creek.

   As the discharge point for the site becomes inundated from Cooroora Creek
   flooding in the major storm event, it is considered that the very minor increases
   noted from the site become inconsequential as a result of downstream site
   being drowned out by creek flooding. The catchment size of Cooroora Creek
   reporting past the site is approximately 1,400 ha. The very minor increases in
   peak flows in the major event would be considered to not result in any
   quantifiable change to downstream flooding conditions.

   15. Provide cross sections – including the finished ground levels of the
       proposed works and neighbouring properties – for the sections marked in
       the snippet below, including a 2m wide footapth:

Updated cross sections are provided through the relevant areas with finished levels.




   16. Provide Unity Water’s written approval for a low-pressure sewer system for
       the proposed development.
   17. If the proposed lots cannot be connected to sewerage reticulation,
       amended plans are required with minimum lots sizes of 2,000m2.

TODs provide the following comments in regard to the Unitywater sewer connections.

There is an existing sewer main traversing the site aligned with the rear of existing
dwellings/properties along Pavilion Street. Noosa A H & I Society Inc (Pomona Show
Grounds) have given their in-principle support to permit the extension of the existing
gravity sewer main within their property to allow the new lots to be fully services by a

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