Adaptation planning is about preparing now for the effects of coastal hazards on our communities, infrastructure and environment so that we are ready for what may happen in the future.
It’s like having a map for a road trip, with different route options that we can take depending on the conditions we experience along the way.
We’re generally following the approach recommended by the Ministry for the Environment (MfE) in the 2017 Coastal Hazards and Climate Change Guidance for Local Government(external link), and modifying it where appropriate for Ōtautahi Christchurch's conditions. For a summary of the MfE recommended process and Dynamic Adaptive Policy Pathways (DAPP) read our fact sheet [PDF, 577 KB].
The guidance document sets out a ten-step process for how we can adapt to the actual and expected changes from climate change. It’s a process that puts community engagement at the centre of decision-making. It takes into consideration everything from our natural and built environment and our cultural values, to community aspirations and expectations.
It also gives us a way to progress things and make decisions, even when there is uncertainty about the rate and effects of climate change.
The Urban Development and Transport Committee endorsed the Coastal Hazards Adaptation Programme report(external link) in November 2020.
It is predicted that New Zealand will experience 30cm of sea-level rise by 2050, 50cm of rising by 2075 and 1m of rising by 2115 (Ministry for the Environment, 2017) [PDF, 12 MB]. Note: This statistic uses a baseline period of 1986 to 2005. We have experienced around 10cm of sea-level rise since this baseline period and therefore expect to see around 20cm of additional sea-level rise over the next 30 years, by 2050
Even if emissions are reduced, it is virtually certain that the global mean sea level will continue to rise through 2100, and there is high confidence that longer-term impacts will be seen for centuries to millennia to come (Intergovernmental Panel on Climate Change, 2021) [PDF, 3.5 MB].
Low lying coastal and inland communities across Ōtautahi Christchurch will be increasingly impacted by intense storms leading to more frequent and extensive coastal flooding, erosion, and rising groundwater.
The New Zealand Coastal Policy Statement 2010 requires local authorities to consider and plan for these risks through pathways such as adaptation planning with communities, and the management of risks through the District Plan (Department of Conservation, 2010) [PDF, 497 KB].
As a region, Canterbury has around $1B of local government-owned infrastructure exposed to coastal hazards, the majority of which is in Ōtautahi Christchurch. As sea levels rise, Canterbury has the most public infrastructure exposed to coastal hazards in New Zealand (Local Government New Zealand, 2019) [PDF, 1.3 MB].
As a city, Ōtautahi Christchurch is more exposed to coastal hazards than either Auckland or Wellington (Parliamentary Commissioner for the Environment, 2015) [PDF, 2.5 MB]. Across the Christchurch district, approximately 25,000 properties are exposed to coastal hazards over the next 120 years.
The updated 2021 Coastal Hazard Assessment potentially impacts around 16,000 properties across Christchurch and Banks Peninsula. Of these properties, around 15,000 are at risk of coastal flooding and 1,000 are at risk of erosion over the next 120 years. The 2017 Coastal Hazard Assessment also included areas further up the rivers, where coastal flooding is less dominant (but remains a factor) and from that assessment approximately 9,000 additional properties (outside of the 2021 assessment) are also likely to experience some coastal flooding.
The National Institute of Water and Atmospheric Research (NIWA) estimates that with 1m of sea level rise the replacement value of buildings in Ōtautahi Christchurch is approximately $6.7B - the majority of which are residential (National Institute of Water and Atmospheric Research, 2019) [PDF, 3.7 MB].
Note that as information is updated, these numbers may change.
Within each type, there are a range of potential options. To achieve the best outcomes for adaptation planning, it’s likely that a combination of types and options will be needed.
For more information on the wide range of possible adaptation options for low-lying and coastal communities, read the full Catalogue of Coastal Hazard Adaptation Options [PDF, 3.2 MB].
If the full catalogue sounds like a bit too much detail for what you’re looking for, we’ve also created a Summary of the Catalogue of Coastal Hazards Adaptation Options [PDF, 1.5 MB], which provides an overview of the types of measures that are used locally, nationally and internationally to manage coastal hazards.
The five main options for adaptation planning are:
We enhance what we’re already doing.
We continue to live in an area while increasing knowledge of the environment and aiming to increase community risk awareness. Options include things like emergency response management, maintaining existing infrastructure, broad district-wide land use planning, environmental monitoring and community awareness-raising.
We live with the hazard.
We continue to use land in an area by raising our tolerance to hazards, which means we can avoid or delay the need to remove or relocate at-risk assets in the short term. Options include things like adapting buildings and infrastructure, raising land levels and managing ground and stormwater.
We keep the hazard away.
We interrupt coastal hazards using soft engineering approaches, hard engineering structures, or a combination of the two to form a barrier between the assets and the hazard. Options include things like shoreline nourishment, seawalls or stopbanks.
We move away from the hazard.
We retreat from coastal areas, or relocate existing and planned development to reduce our exposure to the hazards. The hazard risk to assets is reduced or removed entirely, leaving the coast to respond to natural processes. Options include things like buyouts, land swaps, or leasebacks where property rights are purchased with the provision that the land is leased back to the former owner.
We don’t move into the way of the hazard in the first place.
We use planning tools to avoid increasing the risk of harm to people and property. Options include things like land zoning or setbacks that prevent development in some areas.
Given the extent of our district’s exposure, we need to take a staggered approach to develop community-led adaptation plans.
We’ll be focusing adaptation planning on priority locations where coastal hazards are considered imminent within the next 30 years. Where hazards are less imminent, we’ll focus on raising awareness of hazards to ensure communities are aware of the risk.
This Coastal Adaptation Framework [PDF, 4.7 MB] is a proposed approach for how we will work with communities to develop adaptation pathways that will allow us to plan for, and respond to, coastal hazard risks now and in the future.
The framework sets out:
It is designed to align with the New Zealand Coastal Policy Statement 2010 [PDF, 497 KB], the 2017 Ministry for the Environment’s Coastal Hazards and Climate Change Guidance for Local Government [PDF, 12 MB], and relevant strategies, policies and plans from the Council.
We recognise that adaptation plans for different areas will likely vary, but by establishing a framework with clear principles and an agreed process, we hope to achieve an equitable approach that effectively prepares our communities for the impacts of climate change, regardless of when or where adaptation planning takes place.
This phase focused on setting things up, such as the Coastal Hazards Working Group(external link), and getting the information we need, such as commissioning an updated Coastal Hazards Assessment, appointing adaptation experts Royal Haskoning DHV to provide advice, and developing our processes.
This is when we start the city-wide conversations. While coastal communities will lead their own plans, other parts of the city may be asked to contribute financially, and there may be impacts that are shared across the district.
It’s important we have a city-wide conversation about what kinds of options are on the table, the process for shortlisting them, and how things might be funded.
It’s also important that children and young people are involved in this conversation – climate change is an inter-generational issue and future generations will be living with the impacts of decisions made now.
This phase was concluded on 7 April 2022.
This is when we start talking with specific communities. Because the timing and severity of sea-level rise impacts will vary across the district there is time for adaptation planning to occur in tranches.
This also better recognises the diversity of communities and the different approaches that may best suit each community.
We’re proposing to start adaptation planning with some of the communities in the Whakaraupō / Lyttelton Mt Herbert area. We’ve estimated this phase will take at least 1.5 years to do properly and we’ll be starting in 2022.
As the timing and severity of sea-level risk impacts will vary across the district, we’re doing our adaptation planning in sections. We’re starting with communities in the Whakaraupō Lyttelton-Mt Herbert area.
We chose these communities because, as well as having places that are going to be impacted by coastal hazards, the area has a really interesting combination of factors that make it a great place to pilot our approach.
It’s a mix of an urban and rural environment, with built, cultural, economic, social and ecological interests. It also has infrastructure dependencies, such as roading, which have implications for the wider area.
As we start adaptation planning in the Whakaraupō Lyttleton-Mt Herbert area, we will be using a coastal panel made up of a diverse group of community and rūnanga representatives from the area, along with some city-wide representatives. Where it can be achieved, three Coastal Panel representatives need to be young people, in recognition of the fact that adaptation planning is an intergenerational conversation and the impacts of climate change will be felt for centuries to millennia to come.
The coastal panel should take into account diverse views and interests, rather than advocate for a particular point of view.
The coastal panel will provide informed recommendations to the Council for adaptation plans that allow communities impacted by coastal hazards to respond to changes over time.
Note: The panel doesn’t have the authority to make decisions on behalf of the Council, nor powers of veto.
For more information about the coastal panel and its role, read the Coastal Panel Terms of Reference [PDF, 811 KB].
The Coastal Panel will have the support and assistance of a Specialist and Technical Advisory Group (STAG) – a forum that’s made up of experts in their field. The STAG members are able to provide information, advice and guidance to support coastal panel decision-making.
Because adaptation planning involves weighing up social, cultural, ecological, built and other values, the coastal panel should be committed to the process of adaptation planning, rather than on achieving a particular outcome or focussing on a particular geographic area.
A collaborative agency approach is fundamental to the success of this work programme.
A significant partner for Council in this work is Te Rūnanga o Ngāi Tahu and Papatipu Rūnanga, given the intrinsic values that Māori holds with whenua, wai and the environment.
In recognition of this partnership, two rūnanga representatives have been appointed to the Coastal Hazards Working Group.
In addition, all critical aspects of the work programme to date have had input from Mahaanui Kurataiao Ltd on behalf of Ngāi Tahu.
Alignment with coastal environment planning work led by Environment Canterbury is also critical and two representatives of Environment Canterbury have joined the Coastal Hazards Working Group.
Environment Canterbury has also provided significant staff input to support the development of the work programme to date.
Council is also working closely with the University of Canterbury who are supporting the development of a risk and vulnerability assessment.
Read Mahaanui Kurataiao Ltd's Cultural Narrative - historical occupation and use of the coastal environment [PDF, 1.2 MB].