Development Application - Part 2 of 2 - Report & Plans · OPW11/0116

     5.   CONSTRUCTION

There are a number of ways in which these works could be achieved and the final methodology is at the discretion of the
contractor.

     5.1 Equipment

It is anticipated that the works (depending on the methodology) may require the use the following major equipment:

     •    6" or greater cutter suction dredger and pipeline
     •    Jet pump (suspended or hopper-fed)
     •    Barge
     •    Support vessels
     •    Excavator
     •    Bobcat

     5.2 Methodology for Dredging I Nourishment

The dredge area is to be located accurately using DGPS or suitable alternative. Dredging is to be undertaken slowly to
minimise turbidity. Dredging is to be undertaken in such a way that it does not block navigation once a suitable channel is
established.

Nourishment is to be achieved generally by relocating the pipeline periodically within the deposition area. Small earthmoving
equipment may be used to redistribute material on the visible beach to achieve final nourished profiles. This may be more
difficult to achieve given the presence of significant dead tree material on the foreshore. As the slopes are the same as
existing, final profiling below low tide will likely be achieved by tidal velocities.


     5.3 Methodology for Filling Containers

Filling sand-filled geotextile containers can be undertaken in a number of ways. The simplest methodology includes the
following

     1.   Dredge along the structure alignment to achieve the design depth
     2.   Roll out empty container
     3.   Secure in location with anchor blocks
     4.   Fill container using dredge (while excavating for the next container, per step 1)
     5.   Seal trunks

There are a number of potential variations to this generic methodology. These include:

     •    Excavation for containers may source nourishment and container fill may be sourced from the dredging of channel.
     •    Containers may be filled using a jet-pump suspended from a barge-mounted excavator.
     •    Containers may be filled from an onshore stockpile using a hopper-fed jet pump.
     •    Material may be double handled in some cases.
     •    A frame may be used to secure the container instead of anchor blocks.
     •    Use of temporary bunds may be considered in some locations to stabilise containers during the initial stages of
          filling. These are to be removed upon completion of the works where backfilling isn't necessary.

It is noted that the works will require the use of divers.




     6.   SUMMARY OF KEY ENVIRONMENTAL ISSUES

The works are adjacent to (but not within) the Noosa River Fish Habitat Area. The areas to be dredged are not within a
Marine Park