Name of case study
Pūharakekenui River Catchment
Location
Ōtautahi Christchurch, Aotearoa New Zealand
Year
2002 – current
Scale
Urban/landscape scale
Area / size
0.8 hectares
NbS employed
River / stream rewilding
Type of NbS
Ecosystem restoration
Initiator
Christchurch City Council
Funder
Ministry for the Environment (Jobs for Nature)
Budget
$NZ1.2 billion ($NZ4.5 million from Jobs for Nature)
Design group
The Styx Living Laboratory Trust; Opus; and the local community

- Biomass cover loss
- reduced water quality
- soil erosion
- reduced fresh-water availability
- Biodiversity health and conservation
- climate change adaptation
- disaster risk reduction
- water security and quality
- Creation of a sense of place
- disturbance prevention,
- education and knowledge
- habitat provision
- medicinal resources
- purification
- soil building


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.

References
- Christchurch City Council, Opus International Consultants Ltd. (2017). Pūharakekenui/ STYX River Catchment. Available online: https://ccc.govt.nz/environment/water/waterways/river-catchment-vision-and-values. Date accessed 17 May, 2024.
- Ministry of the Environment. (2022). Urban waterway restoration well underway in Christchurch thanks to Jobs for Nature. Available online: https://environment.govt.nz/what-you-can-do/stories/urban-waterway-restoration-well-underway-in-christchurch-thanks-to-jobs-for-nature/. Date accessed 17 May, 2024.

