Driving up the west coast of the South Island, it’s possible to have the road to yourself; kilometre after kilometre of black-sand beaches, snow-covered southern Alps and towns that have barely changed since the gold rush.

The quiet, traditional lifestyle of the coast is prized by residents, many of whom say they are unfazed by decades of stagnant or declining growth – in fact, they prefer it that way.

There are just over 30,000 “coasters” spread out among a distance of some 500km. According to the latest New Zealand census, the west coast is the only region in New Zealand with a declining population, especially among children, with a 9% decrease in those aged 15 and under since 2013.

During the gold rush of the late 1850s Hokitika had the second busiest port in the country and 91 pubs.

At the height of the gold rush Hokitika was home to 15,000 people. Throughout the 20th century the population fluctuated as extractive industries followed the typical cycle of boom and bust; first gold, then forestry, then coal.

Now, the population hovers around 4,000 and tourism and small businesses employing fewer than five people are the backbone of this salty town, which is home to people who like their space, their freedom and their relatively isolated way of life.

“Do we really need more people in our town?” asks Westland mayor and founder of the Coasters club Bruce Smith.

“What we have now is pretty fantastic. I don’t believe we need huge population growth to have a good life.”

Ninety-year-old Shirley Jones is a lifelong coaster, but says life is getting harder, with dwindling employment options as the extractive industries scale back or close for good.

In Jones’s youth, there was work aplenty, and she says she is worried the only way for the coast to boost its population is migration. It is a trend she isn’t keen on, because she wants to keep jobs for locals.

“At Blue Spur there was a school, a hall and two hotels or what now you’d call pubs. All that is left now is the cemetery,” says Jones, talking from her small, tidy room at the Allen Bryant retirement home.

A view of the coast at Greymouth on New Zealand’s South Island. Photograph: David Munk

“There’s no hustle and bustle here, there’s no traffic jams. The train has gone and you see so many shops closing, it’s a shame. If it wasn’t for the dairy factory, I don’t know what our boys would be doing. It’s hard.”

More than a million tourists visit the coast every year – “lifesavers” says Smith – but the small ratepayer base is struggling to fund infrastructure and facilities for visitors, and more investment from central government is needed, Smith says.

The coast is also experiencing chronic shortages of professionals, including long-term struggles to fill vacancies for doctors, nurses, accountants and lawyers. Smith says he has pushed hard for the government to consider a bonded work scheme for new immigrants, and is “mystified” as to why it isn’t a priority, with New Zealand’s population distribution so unevenly spread.

The outgoing Grey district mayor Tony Kokshoorn is also supportive of bonded migrant schemes, and laments the ongoing decline of his town, 30km north of Hokitika, which is still struggling to recover from the Pike River mine disaster of 2010, in which 29 people died.

However, unlike Smith, Kokshoorn says the west coast needs more permanent residents, not just visitors, and more vitality – “growth is good” – he says.

“The west coast in the past has been reluctant to welcome foreigners and immigrants; coasters thought that foreigners were taking their jobs and that kind of thing,” Kokshoorn says.

Pākehā New Zealanders make up the bulk of Kokshoorn’s constituents, with less than 1% of the country’s Māori population living on the coast.

“But over the last decade I have encouraged that we must be multicultural to get ahead in life. We only have 4 to 5 million people here. New Zealand can actually grow with the help of immigration.”

Kokshoorn says property prices dropped 30% in the nine years following the Pike river disaster and the liquidation and subsequent layoffs by Solid Energy, once the major employer for the town.

Many young, working-age coasters left for highly paid jobs in Australia, and have not returned.

“What we’ve been going through for the last nine years since Pike, there’s no money washing around any more. There are no underground coalmines left in New Zealand now and our district relied entirely on underground coalmines. When I was a kid in 1970 there were thousands working in coalmines,” says Kokshoorn.

White crosses and saftey helmets are pictured on the access road to the Pike River mine. Photograph: Phil Walter/Getty Images

“We’ve gone through a painful transition away from extractive industries to sustainability. And that’s really taken its toll.”

Kokshoorn says the monolithic Warehouse in the centre of town and the rise of online shopping has also killed off the bricks-and-mortar trade of Greymouth, and the knock-on effect has been a loss of street life and vitality.

“We are very isolated here. We also have a lot of natural calamities here. We have a pending earthquake they are talking about all the time. And we get a lot of cyclones now that do a lot of damage. We get severe weather conditions because of the mountain range and the heavy rainfall. They’re tough things to overcome.”

However, Kookshoorn is an optimist and highlights some wins amid the tough decade – namely ultra-fast broadband access, rising tourism numbers and NZ$140m from central government as part of a national regional development programme.

The money – described as a “godsend” – is being used to boost infrastructure for tourism, and to invest in the rise of green minerals, such as lithium.

Down the road in Hokitika, garnet is the latest hope, with the government investing NZ$10m in exploration work.

“Like any other rural place around the world we tend to lose out to the big cities. They get bigger and bigger while we stagnate. When your population is stagnant you haven’t got growth. And whether people want to admit it or not we all live in a capitalist system, and capitalism depends on growth,” says Kokshoorn.

“The whole world is changing rapidly and we have no choice, we can’t ignore it, we have to adjust the best we can. We have to be resilient.”