– Swinging cranes and clawing excavators have reshaped the landscape here, elevating Charlotte’s skyline, expanding its girth and transforming this former cotton-shipment town into the South’s financial hub and one of America’s fastest-growing cities.

But the Queen City also has been steadily unbuilding itself, bulldozing houses and razing apartment complexes along its creeks, ripping up a mall parking lot to reveal a hidden waterway and then stripping away its concrete banks, all in a bid to prevent the flash flooding that turns communities into deathtraps.

The county has removed 460 structures and replaced them with absorbent grasslands, winning national praise as a prototype for regional flood planning that anticipates the impact of projected development and the growing effects of extreme weather. The innovative strategy was ahead of the curve when it launched in the 1990s, by calculating future flood risk and then purchasing — and demolishing — vulnerable homes, businesses and office buildings.

But the region is facing more complex challenges as climate change threatens bigger and more-lasting deluges. Six out of North Carolina’s seven wettest storms have occurred in the past 20 years. In June, following an 11-inch downpour upstream, the Catawba River burst its banks here in a catastrophe that can’t be cured by opening up a few extra acres of flood plain.

“We just can’t engineer ourselves out of this problem,” said Bill Hunt, a civil engineer at North Carolina State University who predicts that more drastic steps will become necessary to move entire communities out of danger.

“What Charlotte has done works very well for two- or three-inch rains,” Hunt said. “But we don’t have tools to fix 11- or 12-inch rains.”

The program, operated jointly by the city of Charlotte and Mecklenburg County, has provided 700 households with voluntary buyouts, replacing their houses and apartments with almost 200 acres of open land that can flood safely. It also gives technical and financial assistance to homeowners looking to elevate their properties above flood level.

The effort is backed by a utility fee on impervious surfaces in homes, government centers and office buildings. The buyout program has cost $64 million, though officials estimate that it has saved $28 million in property damage and unneeded services such as emergency rescues. Charlotte-Mecklenburg Storm Water Services expects the savings will reach $300 million from the homes it has purchased.

About 85% of homeowners who have gone through Storm Water Services’ appraisal process have accepted the buyout. Properties are chosen based on flood risk and an assessment of the financial impact that would follow.

As officials toured the recently flooded Catawba River area last month, they pointed out houses they hope to buy and others that will have to be raised above their current rooflines. They picked out telltale signs of June’s flood: a cushion caught high up in a tree; faint lines of organic matter stuck on windows indicating the high-water mark; branches tangled around a tree trunk revealing the direction the torrents flowed.

It’s all part of their detective work, figuring out how the floodwater behaved so they can advise residents whether they should consider elevating their homes or taking a buyout.

Bill Strain understood some of the flood risk when he bought a two-story house on Riverside Drive in February. But this was his dream house, with a back porch 6 feet above the water and a dock for his powerboat reaching out beyond. Strain and his wife moved in just weeks before June’s deluge, which inundated them and more than 40 other nearby households.

Now, Strain, 72, is at work ripping his walls back to studs and replacing flooring piece by piece. He has dismissed talk of a buyout, but welcomes in representatives from Storm Water Services, hoping instead that they will help him secure grants to elevate his house by about 12 feet.

“They ain’t getting rid of me,” said Strain.

Not everyone trusts Storm Water Services, believing its goal may simply be to oust them and create a park, or suspecting that it is in cahoots with the behemoth Duke Energy, which controls the river’s flow through hydroelectric dams.

Congress appears to be recognizing the dangers that lie ahead. In a rare act of bipartisanship, the House and Senate have pending legislation that would make it easier for communities to set up similar programs to buy people out or elevate their homes by leveraging federal funds.