2020.11.30 - Response to further RFI - OPW200145

   Drawing SW20, SW21, SW22

i) Section B - Is the footpath now partly below top of kerb? How does this work with interfacing with the
   rest of the verge profile for the remainder of the road? Are you proposing to set the footpath down
   locally adjacent to the biopod to minimize the batter? What does his mean in terms of frequency of
   inundation of the footpath at this location? For clarity, provide a dotted line showing the standard verge
   profile on this section.
   Stockwell Response
   The footpath has been raised so this would not result in a vertical step edge. As the streetscape bioretention
   basins have surface runoff enter from kerb and channel, they also surcharge at the kerb inlet level so there is
   little to no risk of footpath inundation from these devices. Please refer to Barlow Shelley drawing 1856-SW20 E
   Section B.




                              Figure 9: Barlow Shelley drawing 1856-SW20 E Section B
ii) The maximum batter angle is to be provided at the most upstream point of the biopod where the batter
    will be steepest.
   Stockwell Response
   The finished RLs have been provided at all ends of the narrow linear basins. All bioretention devices do not
   have a greater batter angle than 1:2. Please refer to Barlow Shelley drawings 1856-SW19E - SW26E.

iii) Inlet sections not consistent with Cross-sections
   Stockwell Response
   All inlet sections have been amended to show the sub-soils in the correct locations. The inlet section is to
   demonstrate the filter surface level relationship to the concrete pit lip in the treatment device.

iv) Update sections B, C, D to be taken at the location of the kerb “cut-out” (i.e.adjacent to the biopod)
   Stockwell Response
   The inlet cut-out has been positioned at the sag (lowest) for each treatment device. This is confirmed by cross
   reference the lip level at the road sag point from the road long sections with the inlet position on the bioretention
   layout plans. Please refer to 1856-SW19E, SW20E, SW21E, SW22E.
v) Provide details for the “400mm cutouts”. There are typical details for a kerb turnout, chute and forebay
   for biopods which can be found from other biopod projects undertaken on the Sunshine Coast. Provide
   calculations showing that 400mm is sufficient to convey the minor design flow or else widen to the
   required width.
   Stockwell Response
   Inlet details have been provided on all bioretention and street tree device plans to demonstrate the inlet function
   into the basins. Please refer to Barlow Shelley drawings 1856-SW19E - SW26E.
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