Sonny Whitelaw explains how the story of work on Braided Rivers is founded on a turbulent geological history.
Before we can protect something, we need to know where it is, why protecting it matters, and what’s threatening it. That may seem pretty obvious.
But what happens when that ‘something’ is a dynamic collection of waterways and globally rare ecosystems that begin life in the Southern Alps of New Zealand, end at the coast, and instead of conveniently staying in a nice defined place, decide at a moment’s notice to change location?
Like everything else about New Zealand, the story of braided rivers is founded on a turbulent geological history. Some of the most biologically diverse and productive systems on Earth, they’re also amongst the most dynamic and challenging.
At any time of year winds can whip up dust clouds, temperatures can plunge from sun-baked to sub-zero, and muddy glacial waters can wash away everything, leaving behind a very different looking landscape.
It’s these dynamic forces that have led to the evolution of plants and animals found nowhere else and in theory, make them the most resilient to climate change.
However, having adapted to live in this incredibly dynamic environment, they also depend on its unique, ever-changing character to survive.
The problem is that by their nature, these rivers and the ecosystems they support, do pesky things like wandering across thousands of hectares of land and flooding entire cities at a whim.
So over decades, we engineered them to within a millimetre of their lives, filled in the wetlands because they were ‘just swamps’, sucked out water as fast as possible to irrigate dairy farms that, in turn, polluted (and still do) what little water was left. And that was after English settlers introduced predators and weeds because they reminded them of home.
All of those actions are not just a problem for the plants and animals that have now become critically endangered. It’s also presenting a growing list of problems for people. The life-supporting ‘kidneys’ of our freshwater systems—wetlands—have largely been eradicated. Braided rivers now confined to narrow waterways can no longer add sediment to the coastal deltas—this once built coastlines to keep pace with rising seas—and aquifers are becoming increasingly polluted, requiring costly and much-resented treatment to ensure safe drinking water.
It’s only in the past few years that there’s been a dawning realisation that oops, maybe we’ve been making a big mistake. BRaid’s role is to draw attention to these mistakes, support the growing number of people and organisations addressing the problems, and share the science that underpins the need to protect these extraordinary ecosystems.
A braided river, or braided channel, consists of a network of river channels separated by small, often temporary, islands called braid bars.