Looking north across the Wairau Bar. Photo: RNZ / Samantha Gee
The Wairau Bar, or Te Pokohiwi o Kupe in Marlborough, one of the oldest and most significant archaeological sites in New Zealand, is at risk of being flooded by rising sea levels, according to a new study.
One of the study's co-authors Corey Hebberd, a descendant of local iwi Rangitāne o Wairau, said the site is important not only for Rangitāne, but for all of Aotearoa.
"Te Pokohiwi o Kupe is one of the earliest known human settlement sites in Aotearoa, it dates back to at least 1250. We regard it as the birthplace of the nation it was a landing site for some of our first settlers," Hebberd said.
"The site itself holds a range of artefacts but also more importantly koiwi tangata, so ancestral remains, and for Rangitāne o Wairau it's a sacred wāhi tapu."
As New Zealand was one of the last places in the world to be settled, Te Pokohiwi o Kupe has a worldwide significance as the landing sight of some of those first settlers, he said.
"It tells a story that's important to us as Rangitāne, but also an important story for Aotearoa, but we think internationally as well," Hebberd said.
The Wairau Bar sits at the mouth of the Wairau River with the sea on one side and a lagoon on the other, leaving it susceptible to erosion on both sides, Hebberd said.
Rangitāne worked in collaboration with NIWA to model flooding impacts in a one in 100 year storm event, he said.
"The current modelling shows that the site could be potentially susceptible to a one in 100 event and be 20 percent inundated, but, obviously, we know that's going to get worse as sea level rise takes place," Hebberd said.
"We're expecting that around the 2050s, sea level will have risen by another half a meter, and when we start getting to that point those storm events start to inundate the site closer to 50 percent."
Even more concerning, as the sea level approaches a one meter sea level rise, which modelling shows will happen sometime between 2070 and 2130, approximately 75 percent of the site could be at risk, he said.
"For me, sometimes these threats, the talk of sea level rise and the talk of the storm impacts, it feels so far away, but we're actually starting to see it now," Hebberd said.
"When we talk about a one meter sea level rise and 75 percent of the site being at risk, that's in my lifetime and that places a real burden and sense of responsibility on my generation."
We have a responsibility to make sure that the stories and the richness of the site isn't lost, he said.
Photo: RNZ / Samuel Rillstone
Recent heavy rains in the Nelson Tasman region have had a negative effect on the site, although it has escaped any major damage. But Hebberd said each major flooding event leads to further erosion.
Protecting the most vulnerable parts of Te Pokohiwi o Kupe from storm events could involve soft engineering, he said. For example, by adding native plants to the bar to bind the soil together and prevent erosion.
"It's a really good opportunity for us to turn our minds to the policy and planning settings that we work within both locally and nationally," Hebberd said. "I mean this site is one of many, not only in our rohe, but nationally, that will be exposed to weather events and so we need to start thinking about how we take care of and protect them."
Hebberd said the collaboration between NIWA and Rangitāne weaved together mātauranga Māori and science.
"Our whānau were really supportive of the work that we did, our whānau were engaged throughout the research project, including contributing interviews, spending time with the research team around their experience of previous flooding events in the area."
Sign up for Ngā Pitopito Kōrero, a daily newsletter curated by our editors and delivered straight to your inbox every weekday.
