WASHINGTON - When flash floods tore through Ellicott City, Maryland, this spring, Governor Larry Hogan called it a "once-every-1,000-year" event - even though it was the second such catastrophe within two years.
Speaking to reporters in May, Hogan was channeling the bewilderment of many communities in the United States at the existential threat posed by the impacts of climate change.
Floods and mega-storms - including two that hit the U.S. East Coast in the past month - are increasingly battering the country, and recovery costs are spiraling upwards.
Yet, the federal government has no overarching plan to deal with a crisis that is likely to render many communities unsustainable, with some experts already calling for a "managed retreat" to safer areas away from coasts and rivers.
Privately, many people are "resigned to the fact that they're on borrowed time in their (waterfront) properties," said Amy Cotter of the Lincoln Institute of Land Policy.
"But then if you talk to a room full of people or politicians, nobody wants to step out there and say we need to sell, to make a change."
About 300,000 coastal homes, valued at almost $118 billion, are at risk of chronic flooding by 2045, according to advocacy group the Union of Concerned Scientists, which predicted in June that the figure would rise to $1 trillion by the end of the century.
Inland, about 41 million Americans are threatened by river flooding - three times the government's current estimate - according to a report earlier this year by researchers from the University of Bristol.
"We have seen escalating flood damage every decade from the 1980s until now, to the point that it almost seems to be doubling every decade," said Chad Berginnis, executive director of the Association of State Floodplain Managers.
Despite the rising threat, he said, it remains difficult to discuss the idea of buying properties and moving populations.
"Politically it just isn't acceptable to a lot of citizens," Berginnis said.
Nonetheless, some municipal governments are coming up with creative responses.
In Ellicott City, that meant a strategy to abandon a flood-prone section of the historic town, which sits in a valley and is crisscrossed by three rivers.
The county council this month approved a five-year flood-mitigation plan, which includes the purchase and demolition of 19 commercial and residential buildings and the expansion of a waterway.
Kelly McMillan, who owns two buildings in the city's downtown, including one where she lives, said she supports the plan.
"It's impossible to see how it would be safe to rebuild properties built over a stream in an area that had two deadly floods in two years," said McMillan.
That approach is becoming more common as communities are forced to grapple directly with the effects of climate change, which are increasingly hard to ignore.
"We have not begun any kinds of discussions about managed retreat, but I've met with all of the major investors and sat down with the maps so I can start that conversation," said Nancy Shaver, mayor of St. Augustine, Florida.
The city is expected to face a sea level rise of two feet (61 cm) by 2030. But even so, Shaver said the discussion is fraught with political pitfalls, as many residents are reluctant to abandon their homes.
"We'll do this at the neighbourhood level," she said. "We'll have to do it very carefully, and we're not there yet."
FOOTING THE BILL
While relocating communities may be safer and less expensive in the long run, the short term question is: Who pays for it?
While the federal government has long funded post-disaster home buyouts, little money has been earmarked for pre-disaster programmes – although there are signs that may be changing.
This month, U.S. President Donald Trump signed a law allowing some of the national disaster relief fund to be used for pre-disaster projects, including home buyouts, according to an analysis by the Pew Charitable Trusts.
The Department of Housing and Urban Development is preparing rules on how to disburse $12 billion worth of pre-storm "mitigation" funding, which can be used for buyouts, said a spokesman.
The government is "helping states and local communities to prepare for future events by committing an unprecedented level of funding to make them stronger and more resilient," said the office of the department's secretary, Ben Carson, in emailed comments.
Such measures are welcome, but do not go far enough, according to Rachel Cleetus, lead author of the Union of Concerned Scientists study, who argued that the United States needs a coordinated national policy around managed retreat.
"We only think about this in the wake of disasters," she told the Thomson Reuters Foundation.
Instead, the country needs "better mapping to find these places ahead of time and give people the option of home buyouts."
She added that only a federal programme would be equipped to deal with thorny issues like deciding how to assist renters versus homeowners, how much taxpayer assistance should go to rich property owners, and easing disruptions to housing markets.
If federal officials decide to take up the task, they may look to communities like Hampton, Virginia, for advice.
The coastal city has experienced eight of its 11 highest storm surges within the past two decades, according to Terry O'Neill, director of the Community Development Department.
In response officials designed a plan, approved by the city council in January, that includes restoring coastal floodplains, as well as several along rivers that run through the city.
As part of a pilot project for that plan, more than a dozen homes have already been removed from areas on floodplains that had been developed, leaving excess water with nowhere to go.
"We're not going to pick up an entire city and move or abandon it," O'Neill said. "We have to figure out how to address these issues to our benefit so we can sustain ourselves."