Pūharakekenui River Catchment

Name of case study

Pūharakekenui River Catchment


 Ōtautahi Christchurch, Aotearoa New Zealand


2002 – current


Urban/landscape scale

Area / size

0.8 hectares

NbS employed

River / stream rewilding

Type of NbS

Ecosystem restoration


Christchurch City Council


Ministry for the Environment (Jobs for Nature)


$NZ1.2 billion ($NZ4.5 million from Jobs for Nature)

Design group

The Styx Living Laboratory Trust; Opus; and the local community

Cavendish Road Stream, Styx Mill reserve, boxed drain before restoration, 2017. Photo by Christchurch City Council.
Climate change benefits
  • Biomass cover loss
  • reduced water quality
  • soil erosion
  • reduced fresh-water availability
Societal / socio-cultural benefits
  • Biodiversity health and conservation
  • climate change adaptation
  • disaster risk reduction
  • water security and quality
Ecological benefits
  • Creation of a sense of place
  • disturbance prevention,
  • education and knowledge
  • habitat provision
  • medicinal resources
  • purification
  • soil building
Pūharakekenui River Catchment. Photo by Christchurch City Council.
Pūharakekenui River Catchment revegetation. Photo by CEP.

Summary of case study

Pūharakekenui River, or The Styx River is one of several spring-fed river systems that originate and flow through Ōtautahi Christchurch. Since 2002 the Styx Living Laboratory Trust have been working hard to keep the river clean, healthy and biodiverse so that it is available for future generations to use and enjoy. The 25 km stretch of the Pūharakekenui River meanders through diverse landscapes, including urban areas, farmland, salt marshes, and reserves. In 2000 the City Council decided to link all of the disparate reserve areas along the river into one continuous restored landscape to support the return of biodiversity.

For local iwi (Indigenous people), the river’s health holds profound significance, as it embodies a spiritual connection to the land. However, the catchment faces numerous environmental challenges, including a lack of riparian vegetation, stormwater contamination, siltation from earthquakes, fish migration barriers, and pest species issues (Christchurch City Council, 2017). Styx Living Laboratory Trust, in collaboration with the Kahukura Rongoa Māori Trust also engages with the local community in relation to Mātauranga Māori (Māori knowledge) and Rongoā Māori (Māori healing). The river flows through Ouruhia, valued by the community for its rongoā, or medicinal plants (Ministry of the Environment, 2022). 

The ongoing urban waterway restoration initiative in the Pūharakekenui River Catchment brings about social, ecological, and cultural benefits to the landscape. This community-driven project aims to rejuvenate the river ecosystem, welcoming back birds, fish, invertebrates, native plants, and people to its flowing waters (Ministry of the Environment, 2022). To date, the restoration efforts have successfully controlled over 8 hectares of woody weeds and planted more than 24,000 native plants in the catchment, with ongoing enhancements anticipated over time.

The restoration’s significance extends beyond ecological benefits, encompassing climate change adaptation and mitigation. By fostering a more absorbent riverbed and implementing measures to manage pollutants and sediment runoff through restored riparian zones and native plant buffers, the project enhances the river’s resilience to extreme events like flooding, thereby bolstering community resilience.

Collaborating with the Styx Living Laboratory Trust and engaging local community members, including youth, underscores the project’s inclusive approach. Beyond environmental restoration, this initiative serves as an educational platform, fostering social connections and environmental stewardship. By empowering residents and nurturing their connection to nature, the project amplifies its positive impact on both people and the ecosystem, embodying a holistic vision of community and environmental well-being.

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Cavendish Road Stream, Styx Mill reserve, boxed drain after restoration, 2017. Photo by Christchurch City Council.

Further resources:

<< River/stream rewilding