A coastal-hazard retreat strategy is a collaboration between Hawke's Bay councils, mana whenua and communities along the Clifton to Tangoio coastal areas. Photo NZME
Managing increasing hazards along the Hawke's Bay coast could come by way of a $2-billion retreat strategy.
Hawke's Bay Regional Council says a "deep dive" planned retreat is the focus of a new report that provides guidance on implementation and estimated costs.
The Tonkin + Taylor report 'Implementation Aproaches and Costs for Planned Retreat' was commissioned by the Joint Committee, leading the Clifton to Tangoio Coastal Hazard Strategy 2120.
It outlines what planned retreat could look like in Hawke's Bay as part of its work on a response strategy, said Joint Committee chair and councillor Jerf van Beek.
The strategy is a collaboration between Hastings District, Napier City, and Hawke's Bay Regional councils, mana whenua and communities along the Clifton to Tangoio coastal areas.
"Our strategy looks at different ways of managing coastal hazards like erosion and inundation due to the effects of climate change on the coast between Clifton and Tangoio over the next 100 years. Planned retreat has been recommended as a long-term response in some areas but we needed to find out more about it," van Beek said.
"Planned retreat has not been well-defined in how it can be achieved at scale in New Zealand. Without a nationally consistent model we wanted to understand how it could be applied in Hawke's Bay."
Council's Asset Management Group Manager, Chris Dolley, said this report enhances local understanding on what planned retreat might look like, what areas might need to be retreated if nothing is done to reduce hazards risks, when by and at what cost.
"The report is clear and does not constitute a recommendation for the implementation of planned retreat in preference to other options. Rather, it gives the community information needed to make decisions," Dolley said.
The report shows that planned retreat is expensive, takes a long time to implement, and has a pronounced impact on the community.
"The report considers different ways to retreat, and explains that each approach has its own challenges.
"As expected, the costs are significant, with a high-level estimate of just over $2 billion to implement retreat over the lifetime of the strategy. The costs include planning, preparation, engagement, enabling investment, active retreat, and cleanup. This helps us to understand the merits of where to defend coastal land to buy time.
"This report gives us a much clearer picture of what might be involved in a planned retreat response, meaning we can better compare different options to manage coastal hazards in Hawke's Bay."
The report does not describe how future costs should be apportioned to landowners, councils, or the managers of infrastructure assets.
Options include the purchase of properties, noting these options have not been proposed, discussed, or decided by the Coastal Hazards Joint Committee, Hawke's Bay Regional Council, Napier City Council or Hastings District Council.
* A regional council proposal asking who should take charge of adapting to coastal hazards between Clifton and Tangoio is currently open and running until 31 July. Feedback can be made at hbrc.govt.nz More information on the Clifton to Tangoio Coastal Hazards project is at hbcoast.co.nz