Kete Tiles

Location: Wellington, Te Whanganui-a-Tara, Aotearoa New Zealand
Project type: Artificial habitat infrastructure
Delivery/lead organisations: Wellington City Council with Isthmus; Tonkin and Taylor
Date/period: 2021–2022
Scale: Site
Primary system or theme: Intertidal habitat enhancement on hard coastal infrastructure

Context

Why this site matters
Wellington’s waterfront includes areas of hard-engineered seawalls that provide little ecological function compared to natural rocky shorelines. These structures simplify habitat, reduce biodiversity, and disrupt intertidal ecological processes. 1 Retrofitting existing seawalls presents an opportunity to reintroduce habitat complexity without removing critical urban infrastructure.

Challenge or constraint

What wasn’t working/what needed to change
Conventional seawalls or constructed foreshores like rock rip-rap typically lack the crevices, pools, and surface variation required by intertidal organisms. This results in reduced species richness and abundance compared to natural coastal systems. 1 Space constraints and infrastructure requirements limit the feasibility of replacing seawalls with “soft” coastal edges, necessitating retrofit approaches.

Intervention

What was done
Kete Tiles were developed as modular concrete habitat units with a woven surface that recalls harakeke kete. They were designed to be attached to the new rock embankment at the southern end of Te Whanganui a Tara, Wellington Harbour. 1, 2 Their purpose is to increase structural complexity and provide refuges for intertidal species by introducing rougher surfaces, edges, crevices, and water-retaining hollows that more closely resemble natural rocky shores. In this way, they are intended to support the establishment of marine life and enhance biodiversity across the intertidal zone. The initiative forms part of Paneke Pōneke, a citywide network of safe biking and scooting routes, and also contributes to Te Aranui o Pōneke, the Great Harbour Way. Their performance is being monitored by Greater Wellington Regional Council in collaboration with Te Herenga Waka Victoria University of Wellington to assess whether they encourage native marine species and how they compare with adjacent areas of the rock revetment left untreated. 2

Key components

  • Precast concrete tiles with woven “kete”-like surface geometry to create microhabitats
  • Cavities and textured surfaces designed to retain moisture and provide shelter during low tide
  • Retrofit installation onto existing seawall structures
  • Materials and form designed to withstand wave action and marine conditions

Implementation notes

Design and delivery considerations

  • Tile geometry draws on both ecological principles and cultural design references
  • Placement within the tidal zone is critical to support different species assemblages
  • Retrofitting required consideration of fixing methods on existing surfaces
  • Pilot installation is being monitored to assess ecological performance over time

Outcomes

Observed or reported outcomes

  • Increased surface complexity compared to adjacent smooth seawall sections
  • Demonstrates feasibility of integrating habitat into existing coastal infrastructure

What is plausible but unmeasured

  • Increased species richness and abundance relative to unmodified seawalls or riprap
  • Contribution to urban coastal ecological networks as stepping-stone habitats
  • Long-term resilience and durability under storm and wave conditions

Evidence and limits

What the evidence supports
Research on eco-engineered coastal infrastructure shows that increasing surface complexity and adding habitat features can enhance biodiversity on seawalls compared to smooth surfaces. 1

Key limitations or uncertainties

  • No long-term data specific to this installation
  • Outcomes depend on water quality and broader harbour conditions
  • Small-scale interventions may have limited impact without wider implementation

Relevance to design practice

  • Demonstrates how existing hard infrastructure can be retrofitted to support biodiversity
  • Highlights the importance of surface complexity and microhabitats in urban marine environments
  • Provides a scalable approach for improving ecological performance of urban coastlines
  • Shows how ecological function can be integrated without compromising infrastructure performance
  • See also Tauranga’s Living Seawall 3 project, and Auckland’s Te Wānanga. 4, 5

References

  1. Jackson, S., Cameron, M., & Paine, M. (2022). Marine habitat enhancement and fauna management at Cobham Drive, Wellington. In Australasian Coasts & Ports 2021: Te Oranga Takutai, Adapt and Thrive (pp. 574–579). Christchurch, NZ: New Zealand Coastal Society.
  2. Wellington City Council. (2021). Kete-like tiles set to be baskets of sealife. wellington.govt.nz
  3. WSP. (2026). Helping rejuvenate the waterfront. wsp.com
  4. Brown, A., Vink, A., Storie, L., & Bullivant, E. (2022). Wave-Structure-Soil interaction for Te Wananga, Auckland’s new waterfront. In Australasian Coasts & Ports 2021: Te Oranga Takutai, Adapt and Thrive (pp. 173–179). Christchurch, NZ: New Zealand Coastal Society.
  5. Dean, D., Pedersen Zari, M., Walker, E. (2026). Te Wānanga case study. In: Aotearoa Design for Biodiversity Guide.