As Hurricane Harvey approached Houston, Kevin Kelly hunkered down in his brick house, which was built in 2009 in a federally designated flood zone.
He set his alarm to ring every two hours throughout the night so he could monitor water creeping closer from a creek overflowing a quarter mile away.
From his upstairs window, as bolts of lightning flashed across the sky and wind battered his walls, he and his wife watched as record-setting rains turned his street into a river.
“The question was how much furniture were we going to put upstairs,” Kelly recalled.
In the end, the water came within 5 feet of his house and no closer. Many of his neighbors were not so lucky.
What helped save Kelly was a Houston building regulation that ensured his house was situated on higher ground than older homes.
No other major metropolitan area in the U.S. has grown faster than Houston over the last decade, with a significant portion of new construction occurring in areas that the federal government considers prone to flooding.
But much of that new real estate in those zones did just fine, a Times analysis has found.
Though Houston has few zoning regulations, it requires that new homes be built at least 12 inches above expected flood levels. The 1985 regulation and others that followed proved widely effective in their biggest test to date — the record-setting rains of Harvey.
Of the nearly 39,000 single-family houses built within city limits since 2007, a total of 3,215 — or 8% — were erected in areas the federal government expects to flood every 100 years, and another 5,529 — or 14% — in areas expected to flood every 500 years, according to property records.
To look at damage to those homes, the Times chose five neighborhoods built inside a flood zone over the last decade and asked a sample of homeowners in each area how they fared. In case after case, owners of the newer homes rode out the hurricane safely.
Their stories are supported by the patterns that are emerging as the city assesses the damage.
The brunt of it appears to be borne by older houses — sometimes just doors away from newer, unscathed real estate — that predate federal and local anti-flooding regulations and account for 79% of the nearly 129,000 houses located in the federal flood zones.
“What you see flooded are housing and structures that were built before the national flood insurance program in the 1980s,” said Carol Haddock, the public works director. “All of those changes since then have increased safety.”
Built on the bayou
Nearly a third of Houston homes are located in a flood zone. Most were built prior to safety rules adopted in 1985.
Annual totals prior to 1975 are presented as a five-year rolling average due to imprecision in the source data.
Sources: Harris County Appraisal District, FEMA, Times analysis
In order to qualify for federally backed mortgages, new homes in the 100-year flood zone must have insurance, which requires they be built above expected flood levels. Houston’s 12-inch requirement, instituted four years after the first federal flood hazard maps came out, was an extra measure of protection.
Surrounding Harris County, which has an 18-inch requirement, has also undertaken a wide range of broader flood-control measures that help Houston. It requires builders to haul out at least as much dirt and concrete as they haul in to prevent filling in flood plains, and to create basins that hold runoff during storms.
Similarly, the city designates “flood conveyance zones” — natural drainage pathways to bayous and creeks — that nobody is allowed to block.
Still, there are limits to what can be done in a place so prone to flooding.
With a population of 2.3 million, Houston is situated about 45 miles from the stormy Gulf of Mexico and gets more rain than any other big U.S. city. All that water drains very slowly, because the city is extremely flat. Hurricane Harvey, the wettest tropical storm in U.S. history, dumped a full year of rain on some parts of the city in less than three days.
“It is easy to point fingers at development, because we are growing so rapidly and we don’t have zoning,” said Steven Costello, the city’s flood czar. “If we did have zoning, we would have been a city that would have flooded anyway.”
“You can’t design for a storm like Harvey where 50 inches of rain fell in three days,” he said. “Harvey flooded four or five counties and impacted every stream and bayou that comes into Houston.”
Compounding the challenge for city planners is the prospect of even more intense hurricanes fueled by climate change.
One of the first steps should be to reassess the current risks, said Robert Bea, an emeritus professor of civil engineering at UC Berkeley whose research shows that eight so-called 100-year floods have hit Houston in the last 27 years.
Much of the flood damage from recent storms hit places not designated as flood zones and therefore not protected by safety rules, according to a recent study published in the journal Natural Hazards Review. More than two-thirds of houses in Houston are not in a flood zone.
“There is a certain uncertainty in any flood map,” said Gerald Galloway, a flood-protection expert who teaches at the University of Maryland and the University of Texas in Austin. “The 100-year elevation is not some magic number that says if you are above this level you are safe.”
Officials from the Federal Emergency Management Agency said it appeared that 68,000 homes in Harris County, most of them in Houston, were flooded by Harvey, though they are still tallying the damage.
Floyd Jennings is among the residents whose houses were built before 1985 and not subject to the flood-protection codes.
His 1968 home took on a few inches of water, forcing him to tear out the flooring, junk his car and discard a refrigerator that was in the garage. Even so, he considers himself lucky compared to others in his area that took on several feet of water.
“It doesn’t take too much flooding to cause damage,” said Jennings, a lawyer and psychologist who supervises the mental health unit of the Harris County public defender’s office. “I will never make fun of an old codger building an ark in his backyard.”
Not all newer construction fared better.
When Paul Womack’s house was built in 2003, it was not in a federally designated flood zone, and so the new codes did not apply. Several years after he purchased the home, flood maps were redrawn to include it in the 500-year zone.
During Harvey, the house took on 5 or 6 inches of water, destroying doors, cabinets, furniture and flooring, while he, his wife and two children remained dry upstairs. The flood came so fast that they didn’t have time to drive out, Womack said.
The damage will run about $50,000 or $60,000, much of which will be covered by federal flood insurance. It was the second time in 18 months that the house flooded.
Womack said he thought about a retirement home in the Texas hill country. But until then he figures he’ll have to live with the risk.
“The majority of people do what I am doing, tear it down, remodel and repair it when it floods,” he said. “If you live near a bayou, you are going to get flooded.”
The biggest challenge for Houston is what to do about all the older houses. It can cost hundreds of thousands of dollars to improve the safety of a low-lying house.
In 2016, after his home in Houston’s Meyerland neighborhood flooded for the second time in two years, Drew Shefman gave himself a choice: move or elevate his house.
In August, crews began digging tunnels under the footings and slab, inserting beams that would be jacked up 10 feet. The lift was scheduled for Sept. 1. But as forecasts of Hurricane Harvey became more worrisome, his contractor moved up the schedule. Nearly half the lift was completed by Aug. 30 — one day before the storm hit.
“They raised us to an elevation of 56 inches and the water line from the hurricane was at 51 inches,” Shefman said.
“I feel guilty enjoying dinner with my family while my neighbors are in an apartment after losing everything,” he said.
Another approach is to reduce flood risks in entire neighborhoods.
Galloway, the flood-control engineer, noted that Milwaukee is buying up houses along flood-prone rivers and removing them. In Sacramento, farmers are paid to flood their fields in the case of emergency storage needs. The most extensive civil engineering has been done in Chicago, where the city is building a multibillion-dollar network of 130 miles of tunnels that are 150 to 350 feet deep to store billions of gallons of rain water.
Houston officials said such a network could help drain water to the Gulf of Mexico in big storms when bayous and creeks overflow their banks.
Another massive proposal would involve building a storm wall across Galveston Bay, protecting the city from a storm surge, though it would have done little to prevent the Harvey flooding.
“You can’t really do anything unless you know what your risk is,” Galloway said. “You can’t bet on what nature is going to do.”
The data analysis in this story has been published as open-source software.
The lead photo is Drew Shefman, his wife Pam and his daughter Quinn inside their elevated Houston home.
Graphics by Raoul Ranoa. Research by Scott Wilson. Digital production by Ben Welsh.