Arahura River

Image: Deb Magner | DOC

Introduction

Arahura River on the South Island’s West Coast is one of 14 priority catchments in our Ngā Awa river restoration programme.

Arahura River has its source in alpine Lake Browning and travels down through natural tussock, rata-kamahi and other forest. Some plantation forestry occurs in the mid and lower parts of the catchment and land beside the lower reaches is used for dairy farming. The Arahura enters the sea about 8 km north of Hokitika.

The upper reaches of the river are part of Waitaiki Historic Reserve and managed by Māwhera Incorporation, a unit of Ngāti Waewae. In 1976 the riverbed itself was formally returned to Māwhera, making it the only New Zealand river that is not publicly owned.

Arahura River is a prized source of pounamu (greenstone), which makes it highly significant to many people in and beyond the local area. The river generally has good water quality, mainly due to high rainfall and its unmodified upper catchment.

The goal of the restoration is to return the river to the healthy state known by previous Ngāti Waewae generations.

See a map of the Arahura river catchment (PDF, 817K)

Treaty partner and project partners

Te rūnanga o Ngāti Waewae, including Māwhera Incorporation, are Treaty partners. They are represented on a steering group that provides essential guidance for the restoration work.

Other partners include West Coast Regional Council, Westland District Council, Westland Milk Products, local landowners and the community.

Current restoration work

Clarifying values and aspirations

With our treaty partners and the community, we are developing a shared vision for the restoration work. A wānanga (conference) was held at Arahura marae in November 2019 and others are planned.

The work involves identifying threats to the river, including from intensifying farming in the lower part of the catchment.

Baseline report

A report on the catchment has been commissioned. It will pull together information about the history, biology and physical attributes of the river and identify threats, challenges and opportunities to help direct the project.

Improving river habitat

Providing more natural vegetation beside the river helps to reduce the amount of sediment and nutrients entering a river and creates spawning sites for whitebait. Challenges in this catchment include high rainfall and natural erosion (slips in the hills and erosion on riverbanks) and difficult access.

Planting natives beside some Arahura River tributaries is planned, although previously planted areas have been washed out by floods. Because this will require a large number of locally sourced plants, we are working with local volunteer and iwi groups to set up a nursery.

Arahura has some introduced willows on its banks and woody weeds in the braided riverbed – its health would improve if they were removed.

A survey to identify habitat for adult inanga and spawning in the Arahura River and its tributaries will be completed in autumn 2020. This will help find sites where improvements could be made.

Pest trapping

Populations of some threatened species in the catchment are being protected and monitored, including whio/blue duck. Predator control has allowed birds including weka and kereru to become more numerous. Some of this work has been carried out by OSPRI. Further predator control could benefit these and other species.    

Contact

Email freshwaterrestoration@doc.govt.nz for more information.

About Ngā Awa

nga-awa-logo-220.jpg

The Ngā Awa river restoration programme began in 2019. It's an extension of our existing work to slow the decline in New Zealand’s biodiversity. The programme focuses on a diverse range of priority river catchments across the country.

Learn more about Ngā Awa's work

Back to top