Climate change, Natural hazards  |  6 Nov 2020

Christchurch City Council wants to begin adaptation planning work with the communities likely to be impacted in the future by rising sea levels.

Council staff are bringing a report to next week’s Urban Development and Transport Committee which seeks the formal endorsement of the Coastal Hazards Adaptation Planning programme.

The programme is the Council’s comprehensive and long-term response to the challenges the Christchurch district faces as a result of coastal hazards caused by climate change and sea level rise.

Within the next 30 years, the Ministry for the Environment predicts that sea levels will rise by around 370mm and by just over a metre by 2100. For a low-lying, coastal city like Christchurch, this means around 25,000 properties will be exposed to coastal flooding and around 1000 properties will be at risk of coastal erosion over the next 100 years.

“We’re proposing to follow the Ministry for the Environment’s guidance which sets out a 10-step process for how we can adapt to the actual and expected changes from climate change,” says Council’s Head of Planning and Strategic Transport, David Griffiths.

“It’s a process that puts community engagement at the centre of decision-making. 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 report recommends starting adaptation planning with some communities in the Whakaraupō / Lyttelton Mt Herbert area. These communities have been identified as a priority for a variety of reasons that includes their exposure to coastal hazards.

“While sea level rise will happen over a longer period of time, we do need to start planning now for how we respond to it, and to the associated coastal hazards like flooding, erosion and rising groundwater,” says Mr Griffiths.

In May 2020 a Coastal Hazards Working Group  with representatives from Council, Environment Canterbury and Ngāi Tahu was established to provide direction and feedback on the programme. Council staff have been working closely with the working group to get the programme to this point.