The sun is out, as usual, in the town of Surfside. Less than 10 miles north of Miami’s world-famous South Beach, just a square mile in size with a population near 6,000, it’s a typically prosperous American seaside community.

Kite surfers zip along the azure waves as locals in flip-flops walk their toy-size dogs – just another south Florida day.

The “snowbirds” from up north will soon fly in for the winter. Surfside’s mayor, Daniel Dietch, arrives at the town hall, kicking up his Sector 9 skateboard. A 50-year-old husband and father of two, his day job is in environmental consultancy. “There are few things better to start the day than a jog on the beach, watch the sunrise and let the ocean breeze envelop you,” he said.

But not all is rosy. Surfside’s picture-postcard beach is doing a slow-motion disappearing act – increasingly scoured by huge storms and encroached upon by rising sea levels, accelerated by the climate crisis.

Gorgeous sandy beaches are fundamental to Florida’s economy. A record 116.5 million tourists visited Florida in 2017, up 3.6% from 2016, generating commerce valued at $67bn.

But holding back the effects of hurricanes and high water is a project on an industrial scale – and one that’s only becoming bigger and more fraught. Some are even talking about “sand wars” in the Sunshine state.

Since the 1950s Florida authorities have spent $1.3bn “nourishing” the beaches – periodically buying in supplementary sand. Despite a huge effort, nearly half the state’s 825 miles of beaches are now considered “critically eroded”.

And complications abound amid not just a local or US but a worldwide shortage of sand. Dredging and mining sand offshore causes environmental damage to the ocean floor, as does repairing the beach itself. In Florida, turtle nesting season has to be worked around, but smaller creatures just suffocate.

You basically kill a beach when you dump a bunch of sand on top of it Matthew Schwartz

“You basically kill a beach when you dump a bunch of sand on top of it,” said Matthew Schwartz, an environmentalist and executive director of the South Florida Wildlands Association. “Microscopic animals that live in between sand, that create a kind of ecosystem there, are killed, and it creates all kinds of turbidity in the water, damaging the coral reefs.”

Surfside is currently “re-nourishing” its beach after a struggle for cash and supplies.

Like many other beach towns it was applying for Federal Emergency Management Agency (Fema) cash to repair hurricane damage when Dietch read news reports earlier this year that the Trump administration aimed to divert some of that money to build the president’s promised wall on the US-Mexico border.

As Dietch raced to pin down his beach money, Surfside even hired a sand lobbyist, Fausto Gomez, to navigate hurdles with the state and federal government.

“Communities are all looking for dollars for themselves. You have to fend off other communities [and] make sure you’re listed in the priority rankings [to get the money],” said Gomez.

Surfside successfully obtained $17.9m to buy and place 330,000 cubic yards of sand along its one-mile beach.

Northern Florida has more sand to spare than the southern coast but Dietch said there’s “tension” because the northern counties “don’t want their sand being excavated and barged to Miami-Dade county”. Places like the Carolinas also guard their sand jealously. So Surfside and many other Florida resorts turn to a sand mine near Lake Okeechobee north of the Everglades wilderness area.

As offshore sand becomes more elusive, south Florida beaches are instead replenished by the truck load from inshore mines. Surfside is currently in the process of having 18,000 truckloads of sand delivered 127 miles from Lake Okeechobee in order to extend its shrinking beach 150ft out into the Atlantic.

The US Army Corps of Engineers awarded the Surfside contract to the private sector to add the sand to the beach. Once Surfside is finished there will be a similar repair project undertaken in South Beach.

Meanwhile the corps is working on ways to recapture sand that has been washed away and it also searches for dwindling nearshore dredging sites. But that’s controversial, too.

“There’s noise in the background about wealthier counties wanting to mine sand off the coast of counties that are less developed,” said Tom Tomasello, a former general counsel for the state environment agency.

He added: “That’s going to be a big political issue as time moves on. There is going to be a sand war one day, I can tell you with certainty.”

The US Army Corps of Engineers’ Laurel Reichold said her worries about the resilience of these communities keeps her up at night.

“A lot of these beach projects, they’re sort of the first line of defense and that’s ultimately why we’re doing storm damage reduction, but it’s not going to prevent damages when you have those direct hits from a category 5 hurricane,” she said.

And the inherent (and market) value of sand is on the rise everywhere.

Reichold said project costs have increased 30% over the past three years.

Some want to dig for supplies overseas. The Florida Republican senator Marco Rubio last month reintroduced a bill that’s failed before, calling for a way around federal laws banning the import of sand, so that his state could go shopping with public funds for gorgeous, cheap sand from the Bahamas less than 100 miles east of Florida’s Atlantic coast.

He is arguing there’s an especially acute need because early September’s Hurricane Dorian damaged some Florida beaches.

The double irony is that, first, the damage happened even though the storm didn’t make landfall in the state, instead wreaking destruction in parts of the Bahamas, and second, climate experts point out that such storms are being exacerbated by global heating, whereas Rubio only recently began softening slightly on his long-held, hardline denials of a human-caused climate emergency.

Palm Beach county alone saw 539,695 cubic yards of sand, enough to fill 165 Olympic-size swimming pools, swilled by Dorian from beaches the county owns and manages a pebble’s throw from Donald Trump’s Mar-a-Lago private oceanside resort.

The county has a dredging program, but wants to keep the sand for local needs.

“Some of the counties to the south of us are really running low,” said Andy Studt, who manages Palm Beach county’s beaches program.

“I wouldn’t say we’re going to share it. We’re not actively advertising that we have excess sand because we know that we have enough to get us through the next couple decades, but that’s it.”

Each year, the cycle continues. Hurricane season brings stronger storms and rising sea levels bring higher tides. Beach repair is the first line of defense, leading to an increasingly costly and desperate scramble for sand. But the bigger picture is just too overwhelming for many Floridians to contemplate.

The National Academy of Sciences asserts that global sea levels could rise more than 6ft by 2100, twice as much as previously predicted, making much of Florida uninhabitable.

“If it turns out the amount of sea level rise corresponds to what scientists are saying, there’s going to be a retreat [from the area],” said Tomasello, the environmental lawyer. “That’s going to be the only option because you’re going to be living in the water 50-100 years down the road.”

Dietch said the town is getting ready to unveil a climate crisis action plan and build a “resilience fund” that’s “a euphemism for planned relocation” for people at risk from rising waters.

“We’re seeing more intense storms. It’s not the frequency, it’s the intensity and patterns of the storms. So we try to message this but not in a fearmongering sort of way because people will shut down,” he said.

Talk that gets too alarming also attracts what Dietch called “pushback” from real estate agents.

“They don’t want people to know that they’re buying in … that it’s a high-risk area,” he said.

And with thousands of trucks of fresh sand arriving at top dollar to disguise the environmental reality, there’s plenty to stick one’s head in for those who prefer that approach.