Reconstruction of Rock Revetment Seawall at Oneroa Bay on Great Barrier Island

This project includes the reconstruction of a 60m long rock revetment seawall located within the coastal marine area at the eastern end of Oneroa Bay, Motairehe, Great Barrier Island. The site is located at a known urupa site on the foreshore of Oneroa Bay, Motairehe, and the revetment seawall is required to provide protection to the existing foreshore embankment and urupa that is directly supported.

The existing coastal revetment at the site has failed through inadequate original construction and requires to be replaced with a robust structure in order to mitigate potential damage to the urupa site from ongoing coastal erosion. The seawall is to be constructed from large, clean and dense homogenous rocks placed over a geotextile layer to form a robust rock shoulder revetment structure.

The rock material is to be salvaged and reused from the existing site where appropriate, and supplemented with good quality locally quarried rock of a similar appearance.

Resource Consent for the reconstruction of the seawall was granted in 2018 and the construction shall be completed in accordance with all conditions of the resource consent, with particular attention paid to all archaeological, arboricultural, ecological and coastal marine process requirements. The works are to be procured and commenced within the Auckland Transport 2018 / 2019 financial year.