SDA-1116-034770 - Proposed nbn Facility at 23 Jirrima Cres Cooroibah - Response to Information Request

   -   details of the waterway (stream profile, morphology, riparian habitats);

       Please refer to Appendix B for detailed design drawings of the proposed culvert replacement,
       which incorporates details of the waterway.

       With specific regard to riparian habitats, it is advised that a pre-clearing flora and fauna survey will
       be undertaken by suitably qualified ecologists prior to any construction works commencing, as per
       the requirements of the Nature Conservation Act 1992 (NC Act). This survey will be undertaken in
       accordance with Section 3.2.1 of the Flora Survey Guidelines – Protected Plants, and will survey
       both the clearing impact area associated with the facility, together with a 100 m buffer zone.

       Likely development impacts on riparian Habitats existing in the waterway as a result of the culvert
       replacement will be identified through this process, and suitable management measures will be
       identified at that time. These management measures will then be incorporated into a Construction
       Management Plan.

   -   details of the design features that mitigate the impacts on fish passage, e.g. how the
       proposed culvert meets the design requirements of the self-assessable code WWBW01- Part
       3, Culvert Crossings.

       The following design features have been incorporated into the culvert design to mitigate the impacts
       on fish passage:

       •   The culvert will be installed at approximately 550mm below bed level;
       •   The culvert will be backfilled with bed material won from the site to maintain and simulate natural
           bed surface; and
       •   The culvert will be installed at a minimum of 1200mm wide to allow for fish passage.

   -   Include details of the culvert base, will it be at or below bed level, details of the culvert cell
       bed – e.g. concrete or natural bed, any low flow channels incorporated into the design, and
       dimensions of the crossing - including cross sections of the culvert crossing within the
       waterway.The infrastructure use is proposed within a riparian buffer area. The proposed
       location of the infrastructure use is contrary to Specific Outcome O5 of the Biodiversity
       Overlay Code and is not supported.

       Details of the culvert base are as follows:

       •   The culvert base will be approximately 550mm below bed level;
       •   The base will comprise a concrete slab, backfilled with bed material won from the site;
       •   No low-flow channels are proposed to be incorporated; and
       •   Dimensions of the crossing is as follows:
           o 2mmx1200mmx1200mm reinforced concrete box culverts (RCBCs); and
           o 4800mm long.

2. POI1 – Development will not increase the risk of mortality, disease or injury or compromise the
health and productivity of fisheries resources.

It has been stated that the development does not comply with section 5.1.6 of the self-assessable
code WWBW01- Part 3: Culvert Crossings- “if it is necessary to remove vegetation (marine, aquatic
or riparian) for the development, the vegetation is to be cut no lower than ground level and the roots



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