Our rural landscapes are riddled with hidden gems that most of us never get a chance to stumble upon. The Taumata Oxbow Lake, which is close to the confluence of the Ruamahanga and Waiohine Rivers, is one of those treasured spots that we’ve had the pleasure of seeing for ourselves and more recently working on as a restoration project.
An oxbow lake is the remains of a bend in the river that has since become stillwater with no natural inflow or outlet, as in this case when the Taumata Oxbow was cut off from the Ruamahanga due to a flood or earthquake several hundred years ago.
On our visit, QEII Trust Regional Representative Trevor Thompson walked us through the area, dodging stands of remnant kahikatea, matai, totara, and kowhai that hug the waterline, pausing every now and then to look up at the tree canopy high above our heads.
“The genetics of these old podocarps are left over from the time when the Wairarapa valley was still the most extensive podocarp primary forest in Aotearoa,” he said, turning back to gaze at us and beyond. “It’s just a glimpse of what once was.”
Walking through the trees, it’s hard to get a sense of the scale of the oxbow, which forms a curve much like a waxing crescent moon. To fully appreciate the scale and shape, one needs to view it from above. But below the treetop canopy, as we look across the water carpeted in duckweed, Trevor informs us that despite being a wetland swamp, oxbows can dry up as their water evaporates in the heat of summer. Given the amount of rain, and the wet ground underneath our feet, that prospect seemed a long way off. But seasons and weather patterns change.
We are soon joined by Sarah Catley, Senior Environment Restoration Advisor with Greater Wellington Te Pane Matua Taiao. Sarah has taken an active interest in this particular site and explains to us that the Taumata Oxbow is a “significant natural palustrine and lacustrine swamp” that spans over 7.41 hectares. “It’s one of the few wetlands of this size and type that remain in the region,” she tells us, wide-eyed and brimming with youthful enthusiasm for her job.
According to Sarah, the Oxbow consists of a range of native flora including mature stands of kahikatea, pukatea, and tawa trees, bordered by a range of carex species alongside the water's edge. “Extensive restoration planting has occurred in parts of the Oxbow including totara, kahikatea, tī kōuka, and harakeke. The Taumata Oxbow provides habitat to a variety of native wildlife, some of which hold an “at-risk” declining status.”
As for the area’s biodiversity value, Sarah informs us that a survey undertaken in 2013 found species including weweia, kawaupaka, tūī, māpunga, kererū, riroriro, pārera, kōtare, brown mudfish, and New Zealand longfin eel. “Along with its rich biodiversity value, the Oxbow also has a range of pest plants and animals that threaten the ecological value of the wetland.”
Putting threats aside, we stumble through the undergrowth and into a grassy open patch encircled with young totara planted 25 years ago. Trevor points out another area that was first covenanted in 1992. The aim is to get more of this area placed into covenant. He’s still working on that.
Thankfully, the private landowners — including Mike Warren whose block we are planting — are working with a range of organisations including the Queen Elizabeth II National Trust, Ruamahanga Restoration Trust, and Greater Wellington Regional Council to restore and protect the Taumata Oxbow’s biodiversity value and wetland function.
As Trevor tears away the invasive weeds and makes a new line on which we are to plant the young seedlings, we slowly make our way, spade and plants in hand, to dig holes into the soft wet earth, dwarfed by the trunks of towering kahikatea behind us.
As each young plant goes in, it makes you reflect on the passage of time and how it’s not only rivers that change course and direction, but us humans too. If we can make a difference by planting more trees, we can certainly contribute something positive to the future direction of our environment and subsequent outcomes, making treasured spots like this even more valuable.