Engineering is now so advanced that, with enough money poured in, most construction projects can come up with structures which will withstand the power of storms or moving land for longer than their predecessors managed to ward off such threats.
However, when it comes to mitigating against elements such as climate change or the power of the sea, we all know that subjugation is just a matter of time.
While improved structures may last longer, ultimately the cost of frequent repairs or of insurance becomes too much. They fall into disrepair and crumble.
We tend to think of managed retreat in terms of having to move homes and communities to safer, less hazard-prone, locations.
Think of the problems being faced by residents of Westport when it comes to relatively frequent river flooding, and how parts of the West Coast around Punakaiki and north of the Buller River are being washed away by stormy seas and heavy swells.
Coastal inundation and beach erosion is similarly an issue for people who live along vulnerable parts of the Southland and Otago coasts, and also up the North Island’s east coast.
When pounding waves incessantly batter the shoreline, it is not just the cliffs which crumble as a result of being undermined but also all the infrastructure and services which have been built along the top, too close to the edge.
Soft sedimentary rocks are exposed all along the coast between Warrington and Kakanui and are highly susceptible to erosion.
They include the same weak mudstones that failed spectacularly below Abbotsford in 1979 and that cause slumping on the Kilmog section of State Highway 1.
This week we heard that a coastal road just south of Oamaru is under threat from the sea.
What is worse is it runs past a thin strip of land above the cliffs which has historically been used for two unauthorised rubbish dumps.
But in the meantime, as the waves nibble away at the beach and the base of the overhang, who knows what nasties that erosion could potentially reveal.
The Waitaki District Council has been considering the future of about 2km of Beach Rd, and whether it is a crucial enough byway on which to spend money to stop it falling into the Pacific Ocean. Already a stretch of road near Kakanui has been closed permanently due to coastal erosion.
Mayor Gary Kircher says there are benefits of shoring up the road, but in the council’s mind will be whether it is throwing good money after bad to do so when, in some cases, managed retreat is by far the best option.
The road will be closed for about five months while the old tip sites are emptied and surveyed to confirm the extent of the work needed along Beach Rd.
On the other side of the Alps, the highly problematic Waiho River at Franz Josef is again under the spotlight.
The government has finally announced a $6 million grant to strengthen and extend stopbanks on the river’s south bank to protect farms and homes from frequent damaging flooding when the Waiho is raging.
However, while Westland District Mayor Helen Lash is happy for landowners who have had to wait years for the work to be funded, she says the disbursement is $2m less than expected.
Franz Josef is under attack on many fronts. The slumbering, deadly, Alpine Fault runs through its main street, while the hillside behind the township could slide on to it with any torrential rain event or earthquake.
State Highway 6 is a vital link from the West Coast through the Haast Pass to Otago. Yet it is often closed due to bridges being washed out.
Some engineers believe, after a major earthquake, its days may be numbered through this part of South Westland.
We need to be planning for managed retreat in many places.
We have to remember our grip on this active country is tenuous at best.
