Source: Radio New Zealand
Erosion visible from the Hampden Closed Landfill. Supplied/Waitaki District Council
Plans to fix coastal erosion caused by increasingly big and powerful waves pounding the Waitaki coast could cost $70 million before 2050, with another $80 million needed to protect the entire Ōamaru sewage system by 2125.
In a report commissioned by the district council in late 2024 and publicly released this month, engineering firm BECA found three roads, a railyard, pump stations, a pā site and urupā were at risk.
The report described some locations as extremely vulnerable and others at risk from the next major storm.
BECA’s recommendations included relocating Hampden Cemetery, closing two coastal roads and accepting the loss of private property and land in northern Ōamaru over the next 24 years.
Waitaki District Council has weaved many of the suggested measures into its long term plan.
Mayor Mel Tavendale said the council faced some tough decisions and community feedback was important.
Waitaki Mayor Melanie Tavendale. Jackie Tav
“We’re a coastal community, we are going to be having these challenges and they’re ongoing. We do need to have some brave conversations and work out what’s important to us and what’s not as important because it’s going to get more and more challenging,” she said.
She said not all the land in the report was council-owned, so the council was trying to share the cost with other agencies, such as KiwiRail and the Transport Agency, where possible.
“I guess in a lot of ways the district cannot afford a $70 million spend. We need to prioritise the council-owned land and then we need to work with the community on other strategies,” she said.
“There are a few sites where [the erosion] is always going to be a bit further or a bit less than expected but it’s a well-known issue. How we solve the issue, that’s not as well-formulated at this stage.”
Peak wave heights expected to rise from 2m to 3.5m
The BECA report predicted 100-year peak wave heights could rise from under 2 metres to over 3.5m along parts of the coast by 2125.
Coastal scientist Martin Single said parts of the eastern South Island had been eroding for 12,000 years because of sea-level rise since post-glacial times, accelerated by climate change.
Single, an environmental consultant with Shore Processes and Management, said more storms were expected to hit the coast each year.
“I think it’s good to see that these reports are being written to identify the financial ramifications of coastal erosion around the country and the significance to infrastructure, and where a lot of money is actually going to have to be pushed into either protecting these assets or relocating them,” he said.
Long-time Ōamaru resident Peter De Reus said he remembered playing on fields at Waitaki Boys’ High School that had since washed out to sea.
He hoped the council would consult with ratepayers before deciding whether to abandon or reinforce an at-risk site.
“Obviously, you cannot guard the whole coast. It’s just not feasible to do that but areas where a lot of the town drive and routinely travel, those areas should be hardened and protected, armoured,” he said.
Beach Road future debated
One site in the BECA report, Beach Road North, has already been closed to traffic for several years, partly because of erosion and partly because of excavation work to remove historic waste.
The council had set up temporary fences for walkers and cyclists while it decided whether to reinforce and reopen the scenic coastal route or keep it closed permanently.
BECA estimated road reinforcements would cost almost $12m, while keeping it closed and relocating services would cost about $4m.
Beach Road North has already been closed to traffic for several years. Supplied / Waitaki District Council
De Reus said the temporary closure came as a surprise to many people and there was little support for a long-term closure, even though it was a cheaper option.
“We’re a tourist town and the area landscape around us is critical for us to market the town as for the tourist town. This road was a real big bonus for Ōamaru,” he said.
Ōamaru Ratepayers and Residents Group chair Ray Henderson said he also supported reopening Beach Road, noting it functioned as a backup to State Highway 1.
“Some years ago there was an accident on Mill Bridge [near the town of Herbert], a car actually got jammed on the bridge and that basically brought State Highway 1 to a halt. There’s nowhere else to go,” he said.
Other work ongoing
A Waitaki District Council spokesperson said the BECA report did not include recent work to tackle historic waste at risk of erosion.
‘Project Reclaim’ removed thousands of tonnes of waste from two fly-tip sites on Beach Road North and the former Hampden landfill, they said.
The council had also been reinforcing the coastline, carrying out rock armouring at the Ōamaru breakwater and replacing sections lost during storms.
“In 2025 we had to replace some on the north side of the Holmes wharf following some rough seas and some alongside the Orwell Street pump station when required,” the spokesperson said.
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– Published by EveningReport.nz and AsiaPacificReport.nz, see: MIL OSI in partnership with Radio New Zealand
