Retreating from the risk of disaster

Driving home from work, I sometimes listen to Wallace Chapman and his panel on Radio New Zealand. He asks each of his panel members what they’ve been thinking about; this is a great way to get us hooked into a whole range of topics that might otherwise pass us by.
What I’ve been thinking about is the recovery of people and communities at risk of an emergency.
We have a new entity called the National Emergency Management Agency (NEMA) which will have a key role in both the initial response phase after a geological or meteorological event (such as an earthquake, volcano, flood or tsunami) and the long tail of any recovery.
Emergency recovery is a many-headed beast, and so other government departments will take the lead in some areas such as the recovery of road and rail infrastructure. Think of the massive amount of work following the 7.8 magnitude earthquake in 2016 to repair, and make more resilient, State Highway 1 and the Main North Railway Line from Picton, through Kaikoura, to Christchurch.
Infrastructure relating to the three waters (drinking, waste and storm) is also well covered. Currently, the Department of the Prime Minister and Cabinet holds the funding for three water recovery, which it operates in partnership with local and regional councils. The Department of Internal Affairs is reviewing this, and so we may see changes in the leadership and management of three waters infrastructure. However, one thing is sure; all the critical underpinnings of communities are well covered in recovery exercises.
But what about privately-owned property?
Private and public insurance can pay for the repair of, or retreat from, damaged land (EQC) and damaged housing (private insurers). There has been a lot written about how well that was managed in Christchurch and in Kaikoura following the 2010/2011 and 2016 earthquakes, and how well-covered homeowners are, and I do not intend to canvas that here.
My interest is in the situations where people cannot return to their homes due to the risk of damage rather than actual damage, because neither public nor private insurance covers that.
What about when land shifts and exposes large boulders overhanging homes, or big slips indicate that there is a risk of further slips? The homeowners are not allowed to stay in their homes, are unable to sell their homes (because who would buy them), insurers sometimes refuse to renew insurance policies, and usually homeowners are unable to afford to walk away and start again.
There are also many places around the country from which homeowners need to retreat due to rising sea levels carving away the land (Invercargill, Bluff, Kapiti coast, East Coast of the North Island, and southern Taranaki are some examples). Other areas ripe for retreat include those which are condemned to severe floods year after year (think Whakatane, Edgecumbe, and Matata) or which are situated near active volcanos (such as White Island in the Bay of Plenty).  
In all these cases, not only are homes at risk, so too are the transport life lines and three water infrastructure critical to communities. 

Do we wait for emergencies to eventuate in all their fury so that insurers (public and private) can pay out for actual damage, or should we be anticipating these risks and finding ways to move communities to safer ground in advance?
Regional and local councils are already putting in place regional policy statements and changes to district plans so that requests for new building in areas at risk can be refused, but existing homeowners in those areas are without options.
I wonder if central, regional and local councils could put their heads together about whether it is cost effective to remediate the land is some of these areas of risk and, if not, when and how those areas should go into retreat mode? There might also be a way to agree on a basic formula for who pays for what, in which situations. Would it be a third, a third, a third? Or would homeowners need to become a fourth partner in any such arrangement?
In any case, preparation may be preferable to waiting for disaster to strike before a retreat package can be developed on a case-by-case basis, with a formula for ‘who pays’ painfully reinvented each time.
This is one of the case studies I use in my Public Policy 101 training course to develop and evaluate policy options. Take a look at my course outline and details here and check out my Patreon page here.