Town Planning Report and Appendices - Cooroibah

Performance outcomes                           Acceptable outcomes                                              Response     Comment
PO23 Waterway barriers that are culverts       AO23.1 Culverts are only installed where the site                            The proposed culvert replacement is considered an
provide adequate fish passage for the          conditions do not allow for a bridge.                                         adequate solution for the site conditions.
site, and:                                     And
(1) fish passage is provided for the life
      of the crossing                          AO23.2 The combined width of the culvert cell apertures                      Refer to Response AO23.1.
                                               are equal to 100 per cent of the main channel width.
(2) hydraulic conditions (depth,
      velocities and turbulence) from the      And
      downstream to the upstream limit of      AO23.3 The culvert crossing and associated erosion                           The culvert base will match the current invert less 300 mm
      the structure allow for fish passage     protection structures are installed at no steeper gradient                    with 300 mm of natural bed re-used.
      of all fish attempting to move through   than the waterway bed gradient.
      the crossing at all flows up to the
                                               And
      drownout of the structure.
                                               AO23.4 For the life of the culvert crossing, relative levels                 Refer to Response AO23.3.
Editor’s note: For guidance see the            of the culvert invert, apron and scour protection and the
Department of Agriculture, Fisheries and       stream bed are kept so that there are no drops in
Forestry 2014 Fact Sheet Maintaining Fish      elevation at their respective joins.
Passage in Queensland: What is a Waterway      And
Barrier Work?
                                               AO23.5 The base of the culvert is:                                           Refer to Response AO23.3.
                                               (1) buried a minimum of 300 millimetres to allow bed
                                                   material to deposit and reform the natural bed on top
                                                   of the culvert base, or
                                               (2) the base of the culvert is the stream bed, or
                                               (3) the base of the culvert cell is roughened throughout
                                                   the culvert floor to approximately simulate natural bed
                                                   conditions.
                                               And
                                               AO23.6 The outermost culvert cells incorporate                               Refer to Response AO23.3.
                                               roughening elements such as baffles on their bankside
                                               sidewalls.
                                               And
                                               AO23.7 Roughening elements are installed on the                              Refer to Response AO23.3.
                                               upstream wingwalls on both banks to the height of the
                                               upstream obvert or the full height of the wingwall.
                                               And
                                               AO23.8 Roughening elements provide a contiguous lower                        Refer to Response AO23.3.
                                               velocity zone (no greater than 0.3 metres/second) for at
                                               least 100 millimetres width from the wall through the
                                               length of the culvert and wingwalls.


State development assessment provisions                                        Module 5 — Fisheries resources          5.2 Constructing or raising waterway barrier works in fish habitats state code
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