Town Planning Report and Appendices - Cooroibah

Performance outcomes                      Acceptable outcomes                                             Response     Comment


                                          AO20.2 The drownout characteristics of the waterway             N/A          The design of a drownout is not required as the proposed
                                          barrier allow for adequate fish passage at the site.                         works do not result in a barrier to fish passage.
                                          And
                                          AO20.3 At drownout, the conditions at the barrier are           N/A          Refer to Response AO20.2.
                                          such that:
                                          (1) the tailwater and headwater levels across the weir
                                              are essentially equal
                                          (2) velocities are sufficiently low for fish passage (e.g.
                                              0.3 metres/second) at or close to the edge of the
                                              spillway crest
                                          (3) the weir is fully submerged to a sufficient depth to
                                              allow for fish passage, and for the species and size
                                              classes of fish moving through the site to cross the
                                              weir
                                          (4) to the degree that provides for adequate fish passage
                                              at the site.
                                          And
                                          AO20.4 The frequency, timing and duration of drownout           N/A          Refer to Response AO20.2.
                                          conditions are adequate for the movement requirements
                                          of the fish community moving past the barrier.
                                          And
                                          AO20.5 Delays to fish passage when there are flows in           N/A          The proposed works involve the replacement of an existing
                                          the system but no fish passage in the rising hydrograph                      culvert.
                                          are accurately defined for the design, and avoided or                        The proposed works will not result in delays to fish passage.
                                          limited to a maximum of three days.
                                          And
                                          AO20.6 In assessing whether the inherent barrier design         N/A          The proposed works involve the replacement of an existing
                                          provides adequate fish passage, impacts on lateral and                       culvert.
                                          longitudinal fish movement are considered.                                   As the proposed works will not create a barrier to fish
                                                                                                                       movement, the works maintain for adequate fish passage
                                                                                                                       and further assessment is not required.

PO21 The use of floodgates is avoided     AO21.1 There is an overriding need for new floodgates,          N/A          Floodgates are not proposed as part of this application.
or minimised.                             and other alternatives are unviable.
                                          And
                                          AO21.2 Hydraulic conditions through the floodgates are          N/A          Refer to Response AO21.1.

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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