How decades of Houston development add up to rising flood risk
John Yang: Next: the long road back from Hurricane Harvey.
When the powerful storm hit the Texas coast last August, it dropped more than 50 inches of rain across Houston, the most ever recorded from a single storm. Harvey was responsible for at least 68 deaths and an estimated $125 billion in damage, making it the second costliest hurricane in U.S. history after Katrina.
Five months later, people are still trying to get their lives back to normal.
For the next story in our series After the Storms, Hari Sreenivasan breaks down the problems exposed by Harvey's rising waters.
Hari Sreenivasan: What's it like to see your house like this?
Kathleen Pacini: It is disturbing. I guess I have gotten used to it.
Hari Sreenivasan: Kathleen and Matt Pacini lived here, in the Meyerland area of Houston on the city's southwest side. But on a Saturday night in late August, the rain began to fall, and didn't stop until it had dropped more than four feet of water on the city.
Kathleen Pacini: I went and looked out the front door, and the water was about this far from the top of the porch. I came to the back door and it was rushing up the driveway like a wave.
Hari Sreenivasan: Within minutes, the water was inside their house.
A neighbor called them and told them to get out. They rushed three houses down to Jenna and Chad Arnold's home. The Arnolds had recently raised 18 inches above ground, and it became an island in the river that was now their neighborhood.
Jenna Arnold: Honestly, we just thought we were going to you know get a little rain. Didn't realize it would be 50-some-odd inches, but we really — we didn't feel like we needed to evacuate. We decided we were elevated. We felt safe. We decided to stay.
Hari Sreenivasan: The Arnolds used a sailboat and kayaks to travel back and forth between houses to rescue other neighbors, then gather up what belongings they had left. At one point, 19 people were huddled in their home.
Kathleen Pacini: I was shivering, and I really think it was shock. And a feeling of helplessness. There was nothing — we were stuck there, there was nothing I could do.
Hari Sreenivasan: The Pacinis had flood insurance. Living in a federally designated floodplain, they were required to. Here's how it works: The Federal Emergency Management Agency draws flood maps across the country.
A 100-year floodplain, seen here in blue, means that each year there is a one in 100 chance your home will be flooded. A 500-year floodplain, the area in green, means one in 500, or 0.2 percent chance for the area to be flooded in any year. If you live within these zones, you must purchase flood insurance, though it's at a government-subsidized rate.
And yet, just outside the 500-year floodplain, in the city's northeast, live Jackie and Michael White. They weren't required to have flood insurance, and yet, like tens of thousands of others, they flooded, too.
Ed Emmett: If something went wrong, the maps were wrong. If you have three 500-year events in two years, that must mean your 500-year definition is wrong.
Hari Sreenivasan: Ed Emmett is the Harris County executive. They're called judges in Texas. He's in charge of the more than 1,700 square miles that 4.6 million people call home.
He says the FEMA maps were clearly wrong. And, in fact, as many as half of the flood insurance claims after Harvey came from properties outside of the floodplain. Emmett says the maps need updating because extreme weather is also becoming more common.
Ed Emmett: I hate to use the phrase, but we have a new normal. We now have to assume that these kind of flood events can occur.
Hari Sreenivasan: He points out that while Harvey made national headlines as the worst flooding in U.S. history, it was by no means the first to hit this region in recent years.
In 2015, 12 inches fell in 10 hours over Memorial Day. In April 2016, 15 inches fell in 24 hours, in what became known as the Tax Day Flood. For each of these, the federal government distributed hundreds of millions of dollars in emergency relief and aid.
Ed Emmett: I'm not denying climate change. I mean, all you have do is look at the satellite photos of the Arctic or look at Glacier National Park. I mean, clearly something is going on.
Sam Brody: This area that we are right now is one of the most chronically flooded areas in the city.
Hari Sreenivasan: Sam Brody studies flooding and flood risk reduction at Texas A&M. We're walking along the Brays Bayou, where during Harvey the water level was well above our heads and into the surrounding streets. He says in addition to outdated flood maps and changing weather patterns, the problem of flooding here has been made much worse by development.
Sam Brody: The normal of 10 years ago and certainly 50 years ago is not the normal moving forward, not just because climate is changing, precip patterns are changing, sea level is rising, but the way we're building and redefining these landscapes and fragmenting natural drainage structures is an even bigger problem.
Hari Sreenivasan: Houston is the fourth largest U.S. city in terms of population, and at 627 square miles, it's larger than New York, Chicago and Los Angeles.
Reporting for this series, we drove through seemingly endless miles of highways, office parks, strip malls and neighborhoods. And it keeps growing farther and farther out.
Ed Emmett: This is a fast growing area, and so more and more land is being taken up by development, and it's no secret. Any time you put down concrete or you put down rooftops somewhere, then you have to offset that.
Hari Sreenivasan: The Pacinis lived in Meyerland, blocks from Brays Bayou and in a floodplain, and yet they were surprised when water entered their home.
Kathleen Pacini: Our house had never flooded. I had no reason to expect that it would flood.
Sam Brody: Now, in you're in Katy, and you're moving water out as quickly as possible, that water has to go somewhere.
Hari Sreenivasan: Harvey's rains were historic. But Sam Brody says what's happening way out in Katy, Texas, 20 miles west, where prairie lands are being turned into subdivisions full of roads, rooftops and sidewalks, has an effect down in Houston.
Unlike the prairies, those surfaces don't soak water. They just push it downstream.
Sam Brody: I don't want to suggest that there would have been no flooding in Harvey if we had developed differently. There was a tremendous amount of water. We're in a low-lying coastal area, bayou system with poorly drained, naturally poorly drained soils.
But the impact could have been less if we had made different decisions upstream, for example.
Ed Emmett: We need to turn this area into much more green space. Sometimes, you have to look at Mother Nature and say Mother Nature wins.
Hari Sreenivasan: And yet, in a city famous for its lack of zoning, with individual counties acting in their own self-interest, and in a state known for championing individual rights, that won't be easy. The R-word isn't very popular here, regulations.
Tory Gattis: No, it is not. No, Houston has always been a very free market city. It's been one of our great strengths.
Hari Sreenivasan: Tory Gattis works at the Center for Opportunity Urbanism, a think tank that focuses on how cities can encourage economic growth. He agrees that changes are needed, including stricter building codes and better flood-risk disclosure. But he's also afraid of throwing the development baby out with the hurricane bathwater.
Tory Gattis: Rather than saying, look, here are the requirements for development, if we just start banning development in large swathes of the region, I think that could be very problematic for Houston's long-term future, because it will affect housing supply, which will affect housing prices and affordability, and really hit the middle class, and they won't be able to afford a home.
Sam Brody: There is not one simple solution.
Hari Sreenivasan: Sam Brody says many decisions by individual homeowners, developers, officials at the local, state and federal levels, made over the course of decades have added up to an overall increased risk of flooding for the greater Houston area.
Getting out of this mess will similarly require great coordination and resolve.
Sam Brody: Hurricane Harvey's devastation was a surprise to a lot of people, but we have been talking about it for decades as a problem.
And one of my bigger worries is what happens when a Harvey-like storm hits in 20 years from now. It's going to be that much worse because we continue to put more people in harm's way and not think about the ramifications over the long term.
Hari Sreenivasan: In our final story, we will explore some of the solutions Brody and others are proposing, and who should pay for them.
For the "PBS NewsHour," I'm Hari Sreenivasan reporting from Houston, Texas.
John Yang: Tomorrow, on Facebook at 1p.m. Eastern, we will host a live discussion with the nonprofit news organization The Texas Tribune, and answer your questions about Hurricane Harvey recovery efforts.