More than $3b worth of Christchurch’s public assets at risk due to climate change

Monday, 21 August 2023

The Christchurch City Council is considering fast-tracking its climate change planning as more than $3 billion of public assets are at risk of flooding in the next 25 years.

Councillor Sara Templeton, who holds the council’s climate change portfolio, is also pushing for the council to introduce a climate levy to help cover the cost of adapting to rising sea levels.

The council estimates that a quarter of Christchurch’s roads, a third of its drinking water and stormwater pipes, and a sixth of its wastewater pipes will be exposed to coastal flooding, erosion and rising groundwater within about 25 years - when sea levels are expected to have risen by about 20 centimetres.

It will cost $3.2b to replace this infrastructure and that figure does not include other council buildings or privately-owned assets.

Council head of planning and consents John Higgins said about a sixth of the district’s residential properties would be exposed to coastal hazard risk if sea levels rose 20cm.

The council started individualised climate change planning last year after splitting the city’s 23 coastal communities into seven groups.

Whakaraupō Lyttelton Harbour and Koukourarata-Port Levy is the first to go through the process, which is likely to lead to recommendations to the council next year.

The council will consider five options when adapting areas to cope with the effects of climate change, including retreating from coastal areas and trying to keep the water at bay by building seawalls or stopbanks.

Living with the hazard while adapting buildings and infrastructure to cope is another option. Not moving into the way of the hazard in the first place is another option, but that is too late for some areas.

The council had planned to go through each area one at a time, but at the existing rate of progress, it would take up to 14 years to complete, Higgins said.

Council staff want to spend another $1.5m each year to employ a second team of staff to scale up the programme, allowing two areas to be worked on at the same time.

Higgins said this would enable the council to complete planning across the city within seven to nine years, providing communities with greater certainty sooner.

“Awareness of the impacts of climate change, particularly after the devastation of Cyclone Gabrielle, has increased some community pressure to scale up.”

However, Templeton said while the council was on the right track with its climate change planning, it was not working quick enough.

She wanted the council to create three teams to work on the community adaptation plans, so the work could be completed in four to five years. Then the council could move beyond the coastal areas to other parts of the city likely to be affected by the impact of climate change.

“These conversations and planning are incredibly important for the future of the city.”

Templeton said communities expected the council to have plans in place ahead of time and there was more of a sense of urgency now the effects of climate change were already being felt.

However, it was going to cost a lot of money, so she had asked staff to look at the possibility of putting in place a climate levy to help the council adapt and move assets and facilities.

“We do need some funding to do proactive things ahead of events. We can not afford to just wait and see.”

Templeton did not want future generations of ratepayers being saddled with the entire cost of adapting to climate change.

“We do know that there will be push back but we do need to look to the future of the city and make sure we have plans in place and have ways of funding them.”

Climate change funding decisions will be considered as part of the council’s 10-year budget, the long-term plan, which will be finalised in June 2024, after public consultation.