In 1999, concerned by the declining state of the Ashley-Rakahuri River near Rangiora, New Zealand, members of the community came together and formed the Ashley-Rakahuri River Rivercare group, ARRG. While different interest groups, from gravel extractors and 4WD enthusiasts to bird watchers, are often on opposing sides of issues, we all had a common desire to reverse the decline in numbers of the unique birds that breed on the river.

From the outset, we worked together with the Department of Conservation, Environment Canterbury, and the Waimakariri District Council to develop and implement a strategy to manage an 18km section of the river from the confluence of the Okuku River downstream to the State Highway 1 (SH1) road bridge.

Regular pest trapping, bird monitoring, and public education campaigns began in earnest in 2004.  For the next few years we received funding from WWF, Pacific Development and Conservation Trust, NZ National Parks and Development Foundation, and the NZ Lottery Grants Board.  The co-operative model worked.  So in 2007, we organised a braided river birds workshop. That led to the formation of BRaid, an organisation that advocates for braided rivers across the South Island.

In 2010 we won the Canterbury-Aoraki Conservation Award, and in 2018 we won the Australasian Wildlife Management Society annual award for Practical Wildlife Management.

Today, some twenty years after that first meeting, our dedicated volunteers build, install, and check predator traps, monitor bird populations annually, undertake field research, support graduate student research, trial programmes to enhance habitats through weed clearing and island formation with the assistance of a local gravel extraction company Taggart Earthmoving, lead ‘river ramble’ walks during Conservation Week, and regularly visit schools and community groups (see our reports for details). Apart from large one-off projects, for which we seek outside finances, we are largely self-funded through the work of volunteers, some of whom make DOC200 traps that we sell. Plus we are sponsored by a local business, Karikaas, artisan makers of a ‘braided river birds’ series of award-winning cheeses.

It’s not just the birds that benefit. The community as a whole is enriched by the knowledge that a rare ecosystem is right here in their backyard and some of the most endangered birds in the world choose to call it home.

Our job is to ensure that we protect and nurture this environment for future generations.

The Ashley-Rakahuri River is not just a waterway.  It’s a globally rare ecosystem called a ‘braided river’.  These complex ecosystems occur only where a very specific combination of climate and geology allows rivers to form ever-changing and highly dynamic channels or braids that weave across a wide dry gravelly riverbed known as the braidplain.

Periodically, the entire braidplain is covered in water from bank to bank. This vital part of a braided river’s ecological processes is referred to as a ‘fresh’ rather than a flood. Huge volumes of gravel are washed downstream (the entire Canterbury Plains was formed by braided rivers), and  when the water recedes, new channels have formed across the braidplain.

This constantly changing environment has given rise to a unique ecosystem of plants, animals, and invertebrates, the most visible of which are the birds. Having evolved to live in this extraordinarily dynamic and challenging environment, some species now depend entirely on braided river ecosystems for their survival.

The Ashley-Rakahuri (the second part of the name is Māori), is some 25km north of Christchurch on the east coast of  the South Island-Te Wāhi Pounamu. Its catchment is the foothills of the Southern Alps-Ngā Puke-māeroero, not the mountains themselves, and so it’s a relatively smaller braided river compared to its nearby big sister, the Waimakariri River.

But size isn’t everything.

Following surveys of Canterbury rivers in the 1970s and early 1980s, the New Zealand Wildlife Service (now the Department of Conservation-Te Papa Atawhai) the Ashley-Rakahuri was one of only five rivers given the highest possible ranking of  ‘Outstanding’ in terms of its wildlife and conservation values.

The shorebird values are well-recognised. The river and estuary are included in a list of wetland sites which meet criteria prescribed to be of international importance by the International Union for the Conservation of Nature (IUCN).

Away from the coast (and a few remnant wetlands) braided rivers are the only remnants of the original Canterbury Plains’ ecosystems still reasonably intact. But their ecological values are increasingly under threat. Most have been invaded by weeds and introduced mammalian predators, and are further degraded by a wide variety of human activities.

The Ashley-Rakahuri is no exception. Declining bird numbers over the last 25 years have led to its more recent classification of a river of  ‘national’ importance.