The Resilience Blueprint – How to prepare coastal communities for climate change
More than 75% of Kiwis live within half a kilometre of the coast – that’s great in terms of lifestyle but alarming when you consider sea-level-rise.
If global temperatures continue to climb and sea levels keep rising, many of these coastal communities will experience significant change - they risk damage to their homes and towns and risk losing access to their amenities.
"The main issue is that we can’t stop nature, and the work that’s being done to reduce global temperatures has a lag-time which means sea levels will continue to rise for fifty or so years after the planet’s atmosphere starts cooling”, says Natural Hazard Resilience Sector Director and chief coastal engineer, Richard Reinen-Hamill.
“Our job, as experts, is to help communities understand what are their current issues, and what may happen over the next 30-100 years and to work with them to identify their options when faced with the range of climate scenarios that could play out. This is a new process called ‘adaptive management’ which helps them plan for a more resilient future."
The three councils in Hawke’s Bay and their respective communities have, unfortunately, found themselves on the frontline of climate change with sea-level-rise and coastal erosion already resulting in impacts to communities along the coastline so they have joined forces to agree on an adaptive strategy which sets out a plan for the next century.
The tricky thing is, we don't actually know how much the sea level will rise or by when, which means "there’s not a one-size-fits-all” solution that can be done now.
What is an adaptive strategy and how does it work?
An adaptive strategy is a measured approach to planning for the uncertainty of sea-level-rise – it’s a series of flexible options that can be employed as and when the impacts of climate change are observed and only at the time when certain thresholds are met.
Some of the flexible options include:
“Soft” nature-based works such as beach renourishment – an interim defence measure to build up the natural coastal barriers that allow the continued enjoyment of the coast:
Control structures that stabilise the coastal edge (e.g. groynes and breakwaters):
Sea Walls – a more expensive and permanent defence option that can serve as a robust way of protecting properties but are intrusive with many potential adverse effects on the environment and are costly to remove:
‘Managed Retreat’ – this is a final, longer-term solution that seeks to make changes to the community to avoid, or reduce, risks. This is likely to include a plan to progressively relocate critical assets, access and buildings over a period of decades:
The development of the Hawke’s Bay Adaptive Strategy is a significant milestone project in Tonkin + Taylor’s 60-year history – it is considered to be the blueprint process to deal with the threat and impact of climate change and sea-level-rise for our communities.