HOUSTON — The mayhem that Hurricane Harvey unleashed on Houston didn’t only come from the sky. On the ground, it came sweeping in from the Katy Prairie, some 30 miles west of downtown.

Water drains naturally in this stretch of Texas, or at least it used to. At more than 600 square miles, Houston has grown to be as big as Chicago, Cleveland, Detroit, and Philadelphia combined, a giant spread of asphalt smothering many of the floodplains that once shuttled water from the prairies to the sea.

When finished, the newest road to ring the city and propel its latest expansion, called the Grand Parkway, will encircle an area equivalent to all of Rhode Island.

For years, local authorities turned a blind eye to runaway development. Thousands of homes have been built next to, and even inside, the boundaries of the two big reservoirs devised by the Army Corps of Engineers in the 1940s after devastating floods.

Back then, Houston was 20 miles downstream, its population 400,000. Today, these reservoirs are smack in the middle of an urban agglomeration of 6 million.

Many of the residents living in and around the reservoirs didn’t even know they slept in harm’s way — until the water came pouring in from the prairie during Harvey.

The story of Harvey, Houston, and the city’s difficult path forward is a quintessentially American tale.

Time and again, America has bent the land to its will, imposing the doctrine of Manifest Destiny on nature’s most daunting obstacles. We have bridged the continent with railways and roads, erected cities in the desert, and changed the course of rivers.

Built on a mosquito-infested Texas swamp, Houston similarly willed itself into a great city. It is the country’s energy capital, home to oil and carbon-producing giants, to the space industry, medical research, and engineers of every stripe. Its sprawl of highways and single-family homes is a postwar version of the American dream.

Unfortunately, nature always gets the last word. Houston’s growth contributed to the misery Harvey unleashed. The very forces that pushed the city forward are threatening its way of life.

Sprawl is only part of the story. Houston is also built on an upbeat, pro-business strategy of low taxes and little government. Many Texans regard this as the key to prosperity, an antidote to Washington. It encapsulates a potent vision of an unfettered America.

Harvey called that concept into question. It might have been an unusually bad hurricane, dumping trillions of gallons of water in a few days, even more to the east of the city than to the west, in the prairie, and setting all kinds of records. But it was also the third big storm to slam Houston in three years, dispelling any notion that Houston shouldn’t expect more of the same.

Climate change holds a mirror up to every place its effects are felt. Global warming might not specifically have caused Harvey, any more than a single major league home run can be attributed to steroids.

That said, scientists have little doubt that climate change is making storms worse and more frequent. The floods that ravaged Houston on Memorial Day in 2015 and in April of 2016 — now called the Tax Day flood — left behind billions of dollars in damage. Coming right after those events, Harvey has led even some prodevelopment enthusiasts to rethink the city and its surroundings.

“Harvey caused me to look differently at the world we live in,’’ said Judge Ed Emmett, chief executive of Harris County, which encompasses Houston and much of the Katy Prairie.

A self-described traditional Republican and big backer of the Grand Parkway, Emmett had planned on spending his twilight years in public service saving the Houston Astrodome from demolition. Harvey altered that. Now he thinks his mission is to protect the entire region.

“Three 500-year floods in three years means either we’re free and clear for the next 1,500 years,’’ as he put it, “or something has seriously changed.’’

After every natural calamity, US politicians make big promises. They say: We will rebuild. We will not be defeated. Never again will we be caught unprepared.

But they rarely tackle the toughest obstacles. The hard truth, scientists say, is that climate change will increasingly require moving — not just ­rebuilding — entire neighborhoods, reshaping cities, even abandoning coastlines.

Resettling neighborhoods, making certain places off-limits to development, creating dikes and reservoirs is difficult, both financially and politically. It takes longer than most election cycles. Memories fade. Inertia sets in. Residents just want to get their lives back to normal. Politicians want votes, not trouble.

The number of “heavy precipitation’’ events in the United States has skyrocketed since the 1960s. Since 1980, instances of extreme weather — hurricanes, floods, heat waves — linked to climate change have cost the United States $1.1 trillion.

Studies show that for every dollar spent upfront in preparedness, US taxpayers could save $4 in emergency relief and reconstruction — not counting health costs, the effects of lost jobs and business revenues, and incalculable grief. But that requires politicians to agree.