Australasian Coasts & Ports 2021 Conference, Christchurch
Cobham Drive, Wellington, is the site of a newly constructed footpath and cycleway with 430 m of associated erosion protection in the form of rock revetment. Habitat enhancement over and above rock placement was required to provide habitat complexity and enhanced ecological function post-construction.Show more…
Marine flora and fauna that reside in coastal areas are impacted by anthropogenic changes to coastlines, leading to loss of coastal habitat and their associated ecosystem services. Ecological enhancements or interventions are becoming increasingly common to address human induced changes to coastlines. Drawing on local and international examples, we identified ecological enhancement features to re-instate ecological values in a hard-engineered environment.
The first feature was pre-cast enhancement tiles that were designed to incorporate ecological specifications in tandem with cultural aspects. The tiles were designed at 400 mm x 400 mm (width and height) and 100 mm deep, using concrete with an ‘acid finish’ that provided additional texture and roughness.
Secondly, we recommended retrospective amendments to the rock revetment material in the form of drill-cored rock pools of varying diameter and depth to mimic natural rock pools in the intertidal zone.
The proposed enhancements were designed within site constraints, such as the small tidal range, local site conditions, rock type and size that was used for erosion protection and known fauna (little penguins / kororā) in the immediate vicinity.
Further, to protect kororā using the site for nesting and moulting, T+T ecologists developed a fauna management plan to protect kororā during construction, and to identify appropriate mitigation in the form of Department of Conservation standard nesting boxes that were installed by contractors above high tide and landward of the revetment.Show less…
