Our adaptation planning programme

Between 2005 and 2020, we experienced around 10cm of sea level rise. While a certain amount of future sea level rise is 'locked in' due to emissions that have already happened, there is some uncertainty in how much sea level rise we will see in the future as it is dependent on how we respond to climate change in the coming years.

From a baseline of 2020, it is predicted that we will experience between 14 to 23cm of additional sea level rise by 2050, between 23 to 48cm by 2070 and between 38cm and 1m by 2100. 

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 32,700 properties could be at risk from coastal hazards with 1.5 metres of sea level rise, most commonly from 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, and with 1.5m of sea level rise it is approximately $9.4B. The majority of these buildings are residential (National Institute of Water and Atmospheric Research, 2019 [PDF, 3.7 MB]).

Note that as information is updated, these numbers may change.

There are five main types of adaptation options

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: 

1. Maintain

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.

2. Accommodate

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.

3. Protect

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.

4. Retreat

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.

5. Avoid

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, 3.9 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:

• Roles and responsibilities.
• Proposed principles to guide decision-making.
• A proposed flexible process for engagement and decision-making.

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.

Phase 1: Programme initiation (2020 to 2021)

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. 

Phase 2: City-wide engagement (late 2021 to early 2022)

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.

Phase 3: Collaborative adaptation planning with communities and rūnanga (2022 to 2023)

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’ve started adaptation planning with communities in the Whakaraupō - Lyttelton Harbour and Koukourarata - Port Levy area. We’ve estimated this phase will take at least 1.5 years to do properly.

As the timing and severity of sea level rise impacts will vary across the district, we’re doing our adaptation planning in sections. We’re starting with communities in the Whakaraupō - Lyttelton Harbour and Koukourarata - Port Levy 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 and Koukourarata 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 and specifically including youth, 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.

The panel:

• Considers the cultural, social, environmental, built, physical and economic impacts of coastal hazards, and agree – where possible by consensus – on a shortlist of potential options to address these impacts.
• Considers the broad range of limitations (including technical), thresholds for change and community tolerance to risk, and agree – where possible by consensus, on recommended adaptation pathways.
• Facilitates engagement with the wider community on the proposed options, pathways and triggers for action.
• Considers community views alongside input and expertise from technical and specialist advisors in order to make recommendations to Council on preferred options and pathways.

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].

Read more about the Coastal Hazards Working Group(external link). 

Coastal Hazards Working Group Terms of Reference [PDF, 14 KB].