Source: NIWA – National Institute of Water and Atmospheric Research
That’s the point when coastal communities will have to decide between managed realignment or managed retreat.
Realignment involves removing coastal protection and allowing an area to become flooded, creating a new wetland or salt marsh habitat.
Rather than relying on hard structures for defence, managed realignment depends on natural defences to absorb or dissipate the force of waves.
Future Coasts Aotearoa aims to show how these changes can be made while ensuring coastal communities can remain prosperous.
That’s the solution many councils are looking for, and some have already begun to plan for changes prompted by sea-level rise.
Bay of Plenty Regional Council is studying the rate and the effects of saltwater intrusion into floodplains used for farming. The results will determine when it will no longer be economically feasible to farm, and what the land could be used for instead.
The council also has a community-led funding initiative which supports three coastal hapū with their first steps of adaptation planning.
Thames-Coromandel District Council has 400km of coastline and is finalising its Shoreline Management Plan. It’s the result of three years of consultation and research to manage coastal hazards, coastal erosion and inundation.
Further south, Hawke’s Bay Regional Council is developing its Kotahi Plan to replace its Regional Policy Statement, Resource Management Plan and Coastal Environment Plan.
It has 350km of shoreline and Kotahi will have a focus on managing the coastal environment, human impacts on coastal and marine habitats as well as climate change, sea-level rise and inundation.
Rautenbach says Future Coasts Aotearoa research will provide the science needed by councils responsible for writing coastal management plans.
It will also give guidance to the Ministry for the Environment and will feed into ongoing national policy revision on sea-level rise and coastal adaptation.
“We are hopeful this will build resilience in New Zealand communities as we brace ourselves for the inevitable changes to come.”