Importance of braided rivers
Canterbury’s braided rivers are vital ecological corridors that connect the mountains to the sea, providing essential habitats for native biodiversity.
They have significant cultural importance to mana whenua and support Ngāi Tahu (Kai Tahu using using the local dialect) tikanga Māori (customary practices) such as mahinga kai (mahika kai), the gathering of food and other natural resources.
Braided rivers also provide abundant recreational opportunities, as well as water for groundwater aquifers, hydro-electricity reservoirs and irrigation schemes.
What are braided rivers
A braided river is one that, over some part of its length, flows in multiple, mobile channels across a gravel riverbed and wider braidplain.
The constantly changing paths, multiple shifting channels, varying flows and ability to move laterally across the landscape are what make these bodies of water so unique.
Braided rivers are more than just the active channels and gravel riverbeds. These rivers move across, occupy, shape, and reshape their braidplains over time.
The active river and its wider braidplain provide a mosaic of associated habitat types, such as connected channels (braids), spring-fed streams, wetlands, ponds and drier terraces.
Where you can find braided rivers
Globally, braided rivers are rare and you would need to travel to Alaska, Canada or the Himalayas to find similar examples of what we have right here on our doorstep.
They occur only where a very specific combination of climate and geology allows them to form dynamic braided channels across a wide, gravelly riverbed and even wider braidplain.
Despite their global rarity, there are more than 150 braided rivers in Aotearoa and their floodplains alone span more than 250,000 hectares of the country.
Most of these are right here in Canterbury. Particularly notable are the seven large, alpine-fed braided rivers, Waiau Toa/Clarence River, Waiau Uwha, Hurunui, Waimakariri, Rakaia, Rangitata and Waitaki rivers; and the three foothill-fed rivers, Ashley River/Rakahuri, Selwyn/Waikirikiri (part) and the Ashburton River/Hakatere.
Braided rivers in Canterbury/Waitaha
Wildlife habitat
The dynamic mosaic of habitat types within a braid plain creates a rich and varied home to an impressive variety of aquatic, terrestrial and wetland species, including birds, fish, reptiles, invertebrates, plants, lichens, moss and fungi.
For example, wetlands, spring-fed streams and dryer terraces provide plentiful food sources such as invertebrates and fish, habitat for different types of birds and refuge for fish during floods. The varied habitats are a critical aspect of resilience for river ecology as species are able to move between areas as the river shifts or floods.
Despite the resilience of life in and around these rivers, many of these species are now under threat. For example, Canterbury’s braided rivers support 85 bird species, with many of these species endemic and/or threatened.
A number of these bird species are specially adapted to life on braided rivers and now depend on them almost exclusively for breeding, including kakī/black stilt, wrybill/ngutu pare, black-fronted tern/tarapirohe, and black-billed gull/tarāpuka.
Seven of our braided rivers are classified as ‘nationally important’ for indigenous braided river birds in Canterbury - Waiau Uwha, Hurunui, Waimakariri, Rakaia, Ashburton River/Hakatere, Rangitātā and Waitaki River.
Kakī/Black stilt - Photo credit: Steve Attwood
Wrybill/Ngutu pare - Photo credit: Steve Attwood
Black-fronted tern/tarapirohe - Photo credit: Steve Attwood
Longfin eel/Tuna
Whitebait/Mata
McCann’s skink/mokomoko - Photo credit: Marieke Lettink
Cultural significance
Water is recognised as a taonga (treasure) that provides for and sustains all life. As such, all waterways carry their own mauri (life force) and mana (authority), forming and influencing the landscape and the people who surround the river.
It is a resource that is crucial to wellbeing for Māori - healthy waterbodies provide food, resources, and opportunities to maintain traditional connections and practices.
These practices include mahinga kai (the gathering of food and resources) and manaakitanga (the ability to welcome and host visitors by providing bountiful produce, as a demonstration of hospitality and respect).
Our braided rivers themselves are part of Ngāi Tahu whakapapa and are of paramount importance – representing important routes and trails across the plains to the foothills and to Te Tai Poutini/the West Coast, with historic and contemporary nohoanga/temporary camping sites, tauranga waka/canoe landing sites and mahinga kai resources.
Over time, and with historical use and development, the ecological and biodiversity values of these rivers have deteriorated – our aim is to work together to halt this deterioration and, where possible, revive these values, protecting these valuable environments and resources for future generations.