The Pahurehure Inlet, part of Auckland's Manukau Harbour, is a critical sanctuary for native and migratory shorebirds - including nationally threatened species such as the White Heron and Black Stilt. Through a combination of ecological restoration, community partnership, and conservation engineering, CESA's flagship project aims to restore habitat quality, improve water conditions, and re-establish Pahurehure as a thriving refuge for coastal wildlife.
By CESA on 22 October, 2025
This is an ongoing project! Check back often for updates.
Nestled between Wattle Downs, Waiata Shores, and Conifer Grove, the Pahurehure Inlet is one of South Auckland's most ecologically significant coastal environments. Within its 210 hectares lie two Significant Ecological Areas (SEAs) that form part of a vital chain of habitats supporting wading and shorebirds across the Manukau Harbour. The inlet's mudflats, saltmarsh, and tidal margins once teemed with life - hosting over 19 bird species, including the critically threatened White Heron (kōtuku) and Black Stilt (kakī).
In recent years, however, ecological surveys and long-term monitoring have revealed troubling declines in biodiversity. Once-crowded roosts have become partially vacated, with key species disappearing from the area. Field assessments by the Conservation Engineering Society of Aotearoa (CESA) identified a combination of habitat degradation, invasive species, and human disturbance as the primary causes.
Invasive weeds such as woolly nightshade, pampas grass, and gorse have overtaken native coastal vegetation, choking the natural plant communities that stabilise banks and provide shelter for native birds. These dense thickets also create hiding places for predators - particularly rats and stoats - which prey on eggs and ground-nesting birds. Construction activity, domestic pets, and increased recreational pressure add further stress to wildlife, especially at the inlet's two high-tide roost sites (RS1 and RS2). Meanwhile, stormwater runoff and sedimentation from surrounding suburbs have reduced water quality, smothering feeding grounds and driving changes in mangrove distribution.
To reverse this decline, CESA has launched the Pahurehure Inlet Restoration Project - a long-term initiative combining traditional ecological restoration with innovative engineering solutions. As CESA's inaugural flagship project, it represents a new model for conservation practice: one where engineers and ecologists work hand-in-hand to solve real environmental challenges.
The project's goals are fivefold:
1. Control invasive vegetation and re-establish native plant communities.
2. Manage introduced predators to protect ground-roosting and migratory birds.
3. Improve water quality through better stormwater management and sediment control.
4. Engage local communities and Mana Whenua in hands-on conservation.
5. Implement smart monitoring systems to measure change and guide adaptive management.
The team's approach, referred to as CESA's dual framework of "Technology Enabling Conservation" and "Conservation Enabling Technology", will see engineers join community volunteers on the ground to better understand ecological challenges firsthand. From this practical experience, new tools and techniques will be developed - such as an automated bird counting system to track roost populations, an AI-based bird agitation meter to detect signs of stress or disturbance, and a specialised mechanical tool for pampas grass removal to make weed control faster and more effective.
By blending on-the-ground action with targeted research and development, CESA is building a model that can be replicated across other conservation sites nationwide. This includes establishing monitoring frameworks that align with scientific best practice while remaining accessible to volunteers and schools.
Partnership is at the heart of this work. CESA is collaborating closely with Mana Whenua (Te Ākitai Waiohua, Ngāti Te Ata Waiohua, and Ngāti Tamaoho), as well as Auckland Council, Forest & Bird, and local residents' associations. Early engagement has focused on integrating mātauranga Māori (traditional knowledge) and ensuring that the project's outcomes reflect both ecological and cultural values.
The initiative also aims to bring long-term benefits to the surrounding communities. Restored coastal vegetation and improved water quality will enhance recreation areas, create educational opportunities for schools such as Conifer Grove Primary, and improve wildlife viewing for residents. In the process, it will reconnect people with their local environment - turning a degraded shoreline into a living classroom and a source of local pride.
The Pahurehure Inlet Restoration Project will run in multiple phases over just over two years, beginning with detailed site mapping, ecological assessments, and consenting. Subsequent stages will involve active weed and predator control, technology development, replanting with native species, and ongoing monitoring to track progress against measurable ecological indicators.
Ultimately, CESA's vision is for Pahurehure Inlet to once again serve as a safe haven for wading birds and a cornerstone of Auckland's coastal biodiversity network. By combining conservation science, community energy, and engineering innovation, this project demonstrates how modern tools and traditional stewardship can work together to heal Aotearoa's ecosystems - one shoreline at a time.
