Stay or go? The question looming for Coromandel’s coastal communities

04 May 2021

A managed retreat away from low lying areas may end up being the only viable solution for many Thames-Coromandel communities as the district confronts the financial realities of dealing with the impacts of climate change.

Urgent action has now been recommended for some areas where the existing risk of inundation is already greater than what experts had anticipated. Mercury Bay councillor, Tony Fox, has described the challenge of responding to rising sea levels as the largest any local councillor will face during their time in office.

The latest modelling conducted as part of the Shoreline Management Plans (SMP) process has revealed that large parts of Thames and the Thames Coast are already in serious danger in the event of a major storm, even without any further sea level rise. 

Royal HaskoningDHV, the consultants coordinating the development of the four SMPs for the district, have advised that design, costing and consultation on potential solutions, including managed retreat for these areas, need to be done urgently. “It’s about what could happen and what we are going to do to be ready for it. We didn’t expect that level (of risk) to be apparent right now,” Sian John of Royal HaskoningDHV told the latest meeting of Thames-Coromandel District Council’s Shoreline Management Committee.

Discussions also need to be commenced with Waka Kotahi/New Zealand Transport Agency, with the loss of road access now a serious risk for communities including Colville and Tairua/Hikuai. “[In Colville], on a king tide the water comes over the road now, so that’s going to happen much more frequently as time goes on, so there will be real access issues and that is true of the whole of that Thames Coast Road,” Ms John told the committee.

Detailed reports on the specific infrastructure under threat including schools and homes, is currently being fed back to the Community Coastal Panels charged with providing input into the plans.

While the risk to Whitianga and Cooks Beach was deemed to be short to medium term rather than urgent, it has also been recommended that design and cost benefit analysis of mitigation or retreat options for Whitianga be assessed now, given the scale of such a project. “The consequences of inundation with sea level rise of above 0.5m are predicted to be significant. Hence, as for Thames, a longer-term plan/strategy should be considered in more detail,” the recommendations state.

While it was agreed to seek additional funding under the next TCDC Long Term Plan for additional scoping work, particularly to gain details around the estimated timelines within which adaptation needed to happen, it is already believed that protection measures will be beyond the financial reach of council.

Mr Fox emphasised that even the $180 million estimated cost of protecting the shoreline from Thames to Te Puru alone was beyond what 30,000 ratepayers could afford, and said work needed to be done across the entire Coromandel Peninsula to understand what the solutions would be and the costs so a case could be made to government. “[Then] you can go to Wellington and say we’ve done all the work, so if you want to save this place this is how much, so government where is your money. We (council) are not going to be able to do it, I tell you,” he told the meeting.

TCDC Mayor Sandra Goudie, who co-chairs the SMP Committee, also acknowledged the reality of what that could ultimately mean. “What we can do is look at where we can go and that’s what we are doing now, that’s our adaption option,” she said. 

Concerns were also raised about the future insurability of properties and infrastructure in low-lying areas. “It’s coming to the stage where properties in the line of this danger will either become uninsurable or they’ll end up with a 15 percent excess. We have to be ready for it and we’d better have people in our coastal communities ready for it,” Mr Fox warned. 

Emphasising the committee’s role in ensuring every councillor in the Thames-Coromandel District was up to speed with what the communities they represent are facing, Mr Fox said buy-in was needed from all parties. “If they are not engaged now, get seriously engaged because the biggest thing on this council that any one is going to face and do is this project,” he said. 

As well as submitting to the draft TCDC Long Term Plan to seek council funding for more detailed modelling, the committee also resolved to hold a workshop with both an insurance expert and representatives from Waka Kotahi.

The next stage of the SMP process will see the Community Coastal Panels draft potential adaptive options and evaluate them against the community’s priorities vis-à-vis use of and access to the coast. From this, an action plan will be developed for public consultation.

Pictured: Coastal erosion in front of the Mercury Bay Boating Club in Whitianga.
A managed retreat from low lying areas may end up being the only viable solution
for many Thames-Coromandel communities as the district confronts the realities of dealing with the impacts of climate change.