Wellington City Council (WCC) required the installation of a new rock revetment for coastal erosion protection along Cobham Drive, located in the southern extent of Evans Bay in Wellington Harbour. As part of the consenting process, WCC needed to prepare a Habitat Ecological Enhancement Plan to outline potential ecological enhancements that could be implemented retrospectively following the construction of the rock revetement. 

Tonkin + Taylor was engaged to develop options for marine ecological enhancements across the revetment and showcased a strong multi-disciplinary approach between the coastal engineers and marine ecologists, in consultation with designers (Isthmus Group), to develop a pragmatic bespoke design. Marine ecologists worked closely with engineers and contractors to overcome site constraints such as tidal height, and wave action in the selection of appropriate enhancement techniques. 

The end result included the installation of 40 ecological enhancement tiles and 20 drill cored rock pools into the rock revetment once complete. These enhancements were intended to create habitat complexity, increase shading and moisture retention, to provide additional space for colonisation by marine intertidal species. The use of bespoke enhancement tiles allowed for cultural values to be incorporated, with the design based off a kete or basket weave pattern. T+T marine ecologists were involved throughout the process, including options assessment, design, implementation, and monitoring. Greater Wellington Regional Council and Victoria University will continue monitoring these enhancements long-term to understand what ecological value these have provided. 

T+T was also engaged to manage the effects of construction on little blue penguin / kororā (Eudyptula minor). Pre-works surveys were conducted in association with the Department of Conservation (DOC) to understand whether burrows were present in the works footprint. T+T worked closely with DOC to develop a kororā management plan, which included the installation of kororā nesting boxes away from the revetment, along with adaptive management strategies for accidental discovery of kororā during construction. 


  • Expert advice on design of marine ecological enhancements
  • Marine ecology assessment
  • Resource consent monitoring 
  • Penguin management plans


  • Wellington City Council (WCC)


  • 2020 – 2022

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