Case study

Te Awanga coastal protection

Overview

The Te Awanga coastal community experienced significant flooding from Cyclone Gabrielle and other storm events, threatening private properties and the lagoon – critical infrastructure for Hastings District Council’s stormwater and three waters systems. The project aimed to protect this lagoon and private properties while maintaining public access and environmental integrity throughout the build.

Challenge

  • High Wave Energy: Required a resilient structure to withstand storm surge.
  • Lagoon Protection: Needed a barrier between the beach and lagoon during extreme weather.
  • Community Access: Construction had to preserve access for locals, including surfers, dog walkers, and fishermen.
  • Surf Break Preservation: No impact to the popular right-hand surf break.
  • Tidal Constraints: Construction had to accommodate tidal fluctuations, with the bottom 1 m of the base layer submerged during high tide, requiring precise scheduling and installation techniques.

Project:

Te Awanga

Location:

Te Awanga, Hastings

Size:

1,386 Modules
5 Tier’s High

Timescale:

5 weeks – average placement 65 blocks/day

Structure Additions:

3 Sets Steps
Boat Ramp

Completion:

July 2025

Client:

Hastings District Council

Contractor:

Lattey Group & Agmar Tools

Solution

  • EcoReef® Modular System: Installed 1,386 interlocking concrete units forming a robust retaining wall.
  • Segmented Construction: Built in 15 m sections, enabling efficient base layer installation and reduced tidal disruption.
  • Efficient Logistics: Blocks stacked 3-high for efficient transportation and installed directly from trucks, minimising site footprint and preserving beach access.
  • Sustainable Practices: Used local fill and beach material to reduce project cost, reduced transportation impact and community disruption.
  • Community Access Solution: A precast ramp and step modules were integrated into the EcoReef® structure to provide safe, continuous access for beach users.
  • Scalable Design: The hexagonal modular block system allows for future extension and the addition of extra layers to accommodate sea level rise as funding and environmental conditions evolve.

Result

  • Infrastructure Resilience: The robust EcoReef® structure prevents storm surge from entering the lagoon, safeguarding the fragile land barrier that separates the lagoon, critical council stormwater infrastructure, and the sea.
  • Low Visual Impact: The structure is mostly buried, allowing the beach to behave naturally, only becoming visible during storm events, while providing unobstructed sea views for nearby private properties.
  • Ecological Enhancement: EcoReef® modules planted with native vegetation to promote biodiversity and support local fauna.
  • Community Confidence: Positive feedback from the community due to fast installation timescale of 5 weeks.
  • Scalable Design: Modular system supports future adaptation, including vertical expansion to address sea level rise.