Is this the new normal?
After storms turn Space City into Flood City, experts believe the future could be even worse
When the rains stopped and the skies brightened, Houston once more was viewed by the world through a prism of disaster: thousands of homes and hundreds of thousands of people swamped by a sea of muddy brown water. The misery was fresh. The images were anything but.
Space City might be the preferred nickname, but Flood City is more like it. The furious storm that dumped more than a foot of water across a broad swath of Houston on Sunday night and early Monday brought to mind scenes from another such storm on Memorial Day 2015, which in turn rekindled memories of storms in 2012 and 2013 that produced flood victims of their own.
And future storms are more likely than ever to threaten homes and roadways with inundation, even in neighborhoods that don’t border on creeks or bayous. If there is a consensus among conservationists, engineers, ecologists, hydrologists, urban planners, climatologists and other experts regarding Houston’s prospects in a time of climate change, it is that neither city nor county officials have taken adequate steps to address the realities imposed by life on a rainy coastal plain.
“This should not have happened like this,” said Phil Bedient, a civil and environmental engineer at Rice University who heads a research collaborative focused on severe storms and their effects. “There is something terribly wrong here.”
That something, in general, is no great mystery. Decades of intense residential and commercial development across Harris County, especially on the relatively higher ground north and west of Houston’s center, have taken place with only modest attempts to compensate for change to the area’s natural drainage system. The crucial freshwater wetlands, which collect and retain water, have been destroyed at an alarming pace — more than 65 square miles filled in since the early 1950s, according to research done by coastal ecologist Erin Kinney.
The precise effect of a particular storm on a particular geographic area may be a complex matter. But the prescription for those who make public policy is fairly simple — plan carefully.
The information available to both developers and public agencies is
more detailed than ever, with all the elevation changes in Harris County having been measured by the laser-based technology known as LIDAR and all the stream flows within a particular channel clearly established. An entirely new discipline — geospatial analysis — has emerged to show the impact of human activity within a specific environment. More than ever, new mapping technology can give builders and planners an accurate understanding of how specific projects will affect the land they sit on and the people who live or work nearby.
“It can be built right; it can be done right,” Bedient said. “But you have to have rules, and you have to enforce them.”
Last year, the Chronicle reported that a review of a statistical sampling of permits issued to local developers by the U.S. Army Corps of Engineers found more than half were not in compliance. Those permits required the developers to take certain steps to mitigate wetlands destroyed by their construction. But apparently the work was not done.
“It’s a small sample size, but it identifies a big problem,” Jim Lester, president of the Houston Advanced Research Center, said at the time. “It’s crazy to me that we cover up wetlands, and then we spend a lot of money to build retention ponds.” Ripe for trouble
Of course, as the evidence showed, many of those ponds never get built at all.
Established in 1982, HARC, as it is more commonly known, has as one of its core missions a greater understanding of ecosystems and watershed planning. Bill Bass, a HARC geographer who specializes in geospatial technology, said the detailed research his organi- zation produces should be the backbone for anyone assessing the possible impact of storm runoff.
The starting point, however, is much simpler. The greater Houston area is ripe for trouble if the region’s climate and geography is not always taken into consideration.
“You are dealing with a flat and gradually sloping environment and a drainage system that goes into one central area to drain out to,” Bass said. “You combine those things, and then add more impervious coverage and fewer wetland areas, you have an issue that needs to be addressed. You can only widen the bayous so much. You need to keep water in some of these systems and out of the bayou in the first place.”
Older aerial photos of the Katy prairie, for example, would show lots of small ponds popping up in low areas after a large rainfall, Bass said. More recent photos tell a different story.
“There is a lot of development taking place there and covering up those ponds,” Bass said. “Where is all that water going to go? A large part of it used to stay in place.”
More and more often, where it goes — long before it ends up in a bayou or, ultimately, Galveston Bay, is someone’s living room.
Mayor Sylvester Turner said he is going to appoint a “flood czar” to try to bring order to a planning process that too often is patchwork and inadequate. Turner stressed that a solution cannot be imposed from the top down by one governmental body.
“It’s a regional issue, and it’s going to take all the different partners sitting at the table,” Turner said. “What you do in one area impacts another. What happens in one part of town impacts people down below.”
Historically, developers have had their way in Harris County. During the 1970s, ’80s and ’90s, the home building surge never seemed to end. In an environment that Bedient likens to a real estate “wild west,” new subdivisions and shopping centers to serve them popped up one after another in Katy, Cy Fair, Spring, Tomball and everywhere in between. In time, albeit in many cases quite some time, storm runoff became more problematic.
Some developments included detention and retention ponds, but often they were not enough, and certainly not as good as the natural mini-wetlands that often dotted the undeveloped property. As well-known environmental lawyer Jim Blackburn put it last week, “We have been dumping floodwaters on ourselves in the name of growth.”
As the building spree continues, tracking new highways in the suburban northwest and the so-called Grand Parkway that loops through a lot of former pasture land, the question now is being asked in more strident tones by residents who never thought they had reason for concern: Is this the new normal?
Given the unpredictability of extreme weather, perhaps “new abnormal” might be a more apt description. The fuel for an increasing sense of worry, be it among experts or homeowners, is the po- tential influence of climate change.
While no particular bit of extreme weather can be tied to this broad global trend, the link of slightly higher temperatures to more intense coastal rainfall — and more intense periods of drought — is persuasive to climatologists who understand how slight variations can have serious consequences. Dry spells, too
Houston has experienced a large number of big rain dumps in recent years. It also has experienced quite a few dry spells. Perverse as the memory may seem, Houston received only 5 inches of rain between March and August of 2011.
Such is the hallmark of climate change, when extreme events like drought and flooding increase in intensity. A small bit of warming can melt glaciers and polar ice, raise sea levels, and make local climates act like they’re on steroids. In places like the Texas Gulf Coast, where extreme events have long characterized the weather, the future now seems a bit more ominous.
Are rains like those experienced last week likelier than they used to be?
“In my opinion, the answer to the question is yes, but the next question is how much more, and whether that increase is big enough to need to deal with,” said State Climatologist John Nielsen-Gammon.
Pressed for some rough calculation, Nielsen-Gammon expects an increase in total rainfall amounts up to 7 percent for each degree of global warming. Of course, more rain does not have to equal more flooding.
“This is separate from the issue of how much flooding is produced from a given amount of rainfall, which changes over time due to the built environ--
ment and flood-control measures,” he said.
Records from Nielsen-Gammon’s office show that there’s been a fairly significant increase in the number of years when Harris County has experienced rainfall of 8 inches or more in a single event — a trend that starts around 1986.
Already, this April will go down as the wettest on record, topping a previous record set in 1976. And as most Houston residents know, most of that moisture came in one epic downpour. In fact, Monday broke the record for a daily event measured at Bush Intercontinental Airport with 9.92 inches. New forecasting tool
Still, the most recent climate assessment for Texas shows that the state overall is going to get a lot hotter and a lot drier by century’s end. Other research points to rising sea levels and increased threats to coastal towns as well as more frequent hurricanes.
One bit of good news is that this summer, the National Weather Service will be rolling out a forecasting tool that will help predict flooding on substantially more rivers, streams and bayous. The federal agency along with several academic institutions have developed a highresolution, real-time hydrologic forecasting model for the United States that will predict flows at 2.7 million points along U.S. waterways, including almost 900 in Harris County.
“Basically, water is going to be predicted just like the weather,” said David Maidment, a University of Texas civil engineering professor who’s involved with the project. “It’s a major innovation.”
Using a new $35 million supercomputer in Maryland, forecasters will be able to say where flooding will happen before the rain begins to fall, Maidment said.
“This could be really helpful for an area like Houston,” he said. “Imagine what emergency responders could do with this kind of information.”
Then again, that’s not exactly the help that most neighborhoods consider of prime importance. They want the flooding to stop, and there is no easy way to achieve that. A radical diversion plan for some of the bayous might prevent the more dramatic flooding, but the cost could be prohibitive. Already, it is likely the federal government will have to spend a substantial sum to make improvements to the Addicks and Barker earthen reservoirs, which now have to hold back more water — for longer — than they were originally designed.
“We can’t just engineer our way out of this,” said Jennifer Lorenz, executive director of the Bayou Land Conservancy. “Nature has built this (drainage) in ways we cannot replicate.” ‘Time to get more strict’
Her organization works to protect natural wetlands in the 13 watersheds that drain into Lake Houston. Its success in projects like the Spring Creek Greenway and its 12,000-acre preserve too often are overshadowed by the endless small patches of wetland that get bulldozed every year.
“We will see more extreme weather events, and that’s a catastrophe in the making,” Lorenz said. “It is time to get more strict on floodway development. Businesses in this day are allowed to scrape out old trees on the bayou system and build anything they want.”
Some developers take advantage of wetlands mitigation programs that allow them to enhance wetlands preservation elsewhere, often by simply writing a check. Lorenz is highly critical that the “mitigation bank” concept has any real value.
“These same builders are meeting very stringent requirements in other places and are still making money,” she said. “It is time for Houstonians to gather themselves up and say we cannot continue this way. There will be more and more flooding.”
Which, of course, means higher insurance premiums. And possibly diminished home values. And more deaths. And many more photos of cars bobbing in chocolate water and airboats zipping along where they have no business being.
Rice’s Bedient says it does not have to be this way. Years ago, he lived in Sharpstown before moving out to Sugar Land. He praises Fort Bend County for better and better enforced regulations and a commitment to homeowners. He also praises his old home state of Florida, which has just one agency responsible for watershed management.
“I don’t know what the deal is,” he said of the region’s inability to confront what threatens to be an overwhelming problem. “It’s crazy.”