Annex 7 - Engineering Specifications

  4.3. Placement tolerances
    4.3.1.          ± 0.5m horizontal tolerance
    4.3.2.          ± 0.2m vertical tolerance (except crest)
    4.3.3.          Crest level to be no higher than MHWS and not more than 0.2m below MHWS at
                    time of construction. Crest height to be adjusted, as required, to match oyster
                    recruitment heights at a given site.
    4.3.4.          Settlement of rock is expected to lower the reef patch profile over time.
  4.4. Anchoring of construction vessel not to impact on marine plants. No anchoring within 100m
          of submarine cables.




5. SEEDED CULTCH, UNSEEDED OYSTER CULTCH, LIVE OYSTERS

  5.1. Seeded oyster cultch, unseeded oyster cultch and/or live oysters are to be placed across the
          crest of the oyster reef patches and would typically extend down the batters of the rock
          substrate. Seeding of areas in close proximity to the seabed is to be avoided.
  5.2. Seeded Oyster Cultch and/or Live Oysters are to be placed as a single layer. Stacking or
        layering of cultch is to be avoided. (Target placement volume of 5kg/m2/ with maximum
        10kg/m2).
  5.3. Seeded Oyster Cultch and/or Live Oysters are to be placed by hand into voids within rock
          substrate and interlocked as far as possible to limit loss from the structure.
  5.4. Placement to target more protected areas (less exposed to wave and current) preferentially.


6.0 RECTIFICATIONS

  6.1     Rectifications, where needed, are to be undertaken as per Table 3.

Table 3: Rectifications

Issue            Rectification Response             Specific                Rationale
                                                    Requirements
Settlement       No rectification required                                  Settlement of rock into
of               where:                                                     sandy substrate is
Restoration      - settlement is limited                                    expected. The design
Substrate        (nominally <200mm) and                                     targets a crest height of
                                                                            the reef patches at