Whether we live by the beach, by a river, on a canal or on top of a hill overlooking the ocean, there is no debate that the effects of climate change on our streams, ground water levels, sea levels and accessibility in and out of our communities, in relation to where and how we live, are very real and pertinent.
Shoreline management on the Coromandel Peninsula is an important and current matter. Our future depends on it. Five meetings addressing the pathway ahead for 400km of shoreline were held from Thames to Colville last weekend. Over 60 people attended the two local gatherings in the Whitianga Town Hall and the Kūaotunu Hall.
The central issues of shoreline management are how to protect, prepare for, pay for and manage the varying risks of inundation and erosion. Pictorial maps showed clearly the areas most affected and to what degree. The presenters from Thames-Coromandel District Council brought a practical and sobering message. No one was debating whether there is climate change and there is general agreement that the temperatures are rising, the sea levels will rise and that storm patterns are more intense and severe. Recent storms have highlighted the need for action.
For Whitianga, it was demonstrated that there are areas of real vulnerability that require protection and management. Two areas in particular were identified - the centre of Buffalo Beach and the shores of the estuary to the Waterways canals. One of the presenters said, “State Highway 25 needs to be protected. We considered a new location, but have not found any feasible relocation.”
The presentation pointed out scenarios 20 years, 50 years and 100 years into the future. The key question was “What might protection look like in the future?” to address the hazards that could be predicted for each of these markers. It was demonstrated that these hazards certainly apply to Whitianga and that there were some that will apply within the 20- year marker.
The importance of putting in place triggers that would allow council to act, was stressed. For Whitianga, the questions for each trigger point are “What is the line in the sand” and “What would it take to protect Mercury Bay?” It was explained that there will be an unacceptable level of inundation at a 0.4m of sea level sea rise. Although it is certain that there will be sea level rise between 2020 and 2050, there is no certainty when the 0.4m measurement will become a reality. However, a careful outline was presented with maps and graphs of adaption plans and proposed pathways of protection which would be enacted when certain triggers in the climate change trajectory became clear.
The adaption and protection plans involve immediately addressing the erosion on the middle of Buffalo Beach through replanting, and protection and maintenance of the sand dunes. This was not met with enthusiasm, as residents had witnessed replanting projects washed away by recent storms and expressed that this approach was a “waste of money”. The residents were re-assured that this initial step would be supported by “soft engineering” - the use of diggers to move sand and rock to support and sustain the effects of the replanting.
The long-term scenario proposed for protection of the Buffalo Beach shoreline would be an embankment of 6.4m all the way around the beach and extending into the estuary. However, it was quickly pointed out by the TCDC staff that “this is not a scenario we need to go with at this present time”.
The embankment was described as a big piece of infrastructure which required addressing the questions of “What is the estimated value of this in terms of cost/benefit analysis?”, “What are the ecological and environmental impacts?”, “How will town growth look and develop in this period?” and “How will the options of relocation or enhancing defences be decided?”
It was indicated that decisions in all of these areas would need to be made in the next 20 years, but that adaption and flexibility would be required.
For residents and businesses, insurance is a key issue and this received a very detailed presentation. To quote the presenter, “Climate change requires a paradigm shift in thinking when it comes to insurance.” Three practical steps were advised - anticipate and adapt, build back and raise floor levels. “Unless we reduce risk, insurers will respond through exclusions or refusals, but incrementally,” the presenter said. “The Shoreline Management Plan wants to put in place adaption policies.”
One lingering, but key question on many minds is, “When will what is described, happen?” No one knows the answer to that, but TCDC will watch and monitor carefully the trigger points. Council will set the direction, but not the exact format of what happens. Input from residents will constantly be sought.
Pictured is the shoreline erosion at Buffalo Beach in Whitianga.