Enclosure 4 - Schedule 4a

 12.4 Prescribed tidal work is designed and       The design and construction of the prescribed tidal work is         The permanent oyster reef is composed of oyster
 constructed using materials having a long life   consistent with the following standards—                            shells, which are resistant to attack by marine
 in marine environments, having regard to their   (a) subject to paragraph (b), each Australian Standard relevant     organisms, corrosion, abrasion and immersion in
 ability to resist the following—                 to the materials that should be used, or the measures that          seawater.
 (a) attack by marine organisms;                  should be taken to treat materials used, for structures,
 (b) corrosion;                                   to the extent the requirements stated in the Standard apply to      Once established, the recruited oysters on the reef will
 (c) deterioration resulting from abrasion or     structures located in a marine environment;                         cement the reef together providing stability to the
 immersion in seawater.                           (b) if a relevant planning scheme standard is more stringent than   oyster shell substrate although the rate of oyster
                                                  the standard mentioned in paragraph (a)—t e relevant planning       recruitment is also unknown and likely variable
                                                  scheme standard, to the extent it is more stringent than the        between sites.
                                                  standard mentioned in paragraph (a).
                                                                                                                      During the initial recruitment period, stability is
                                                                                                                      provided by temporary materials (Coir, Manilla Rope &
                                                                                                                      Timber). These materials are biodegradable and do
                                                                                                                      not form part of the permanent structure. The life
                                                                                                                      expectancy for typical coir logs of this size is nominally
                                                                                                                      2 – 3 years however for periodically submerged coir
                                                                                                                      bags filled with oyster shell this could potentially be
                                                                                                                      shorter and is expected to vary between sites.

                                                                                                                      Where recruitment and cementing of the reef substrate
                                                                                                                      is adequate, reefs will successfully become
                                                                                                                      established prior to degradation of the coir product. In
                                                                                                                      cases where recruitment or cementing of the reef unit
                                                                                                                      is too low, reefs may not become successfully
                                                                                                                      established within this timeframe and oyster shell may
                                                                                                                      become uncontained.

                                                                                                                      Coir is naturally resistant to abrasion, however the risk
                                                                                                                      of damage is further reduced by filling the bags using a
                                                                                                                      sleeve and ensuring the bags are well packed to
                                                                                                                      prevent migration of shells within the bag.

                                                                                                                      The works incorporate quarterly monitoring for the first
                                                                                                                      3 years and if any erosion or excessive accretion are
                                                                                                                      observed these can be evaluated and the reef units
                                                                                                                      can be modified, relocated or removed if necessary.




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Coastal Protection and Management Regulation 2003 – Schedule 4A – IDAS code for the development of prescribed tidal work