Streetwise Professor

September 2, 2017

Harvey’s Danger Has Passed (For Most, Though Not All)

Filed under: Climate Change,Houston,Politics — The Professor @ 9:36 pm

The last several days in Houston have been warm and sunny. Most stores are open (with the surprising exception of a local Starbucks), traffic is getting back to normal–unfortunately (I-610 in particular is a nightmare). There are still flood waters in some locations, but most of the water has drained. I drove on US-59 (I-69, which nobody calls it) yesterday. Here’s how it looked a few days ago.

us59_kayak_at_hazard_dave_rossman

Some of the bayous are pretty much back to normal. Here is Brays (or Braes) Bayou, at Calhoun Rd. near UH, as of Friday–less than 48 hours after the rain stopped.

brays_bayou_calhoun

That doesn’t look much different than on a normal day. (This bayou has been subject to a lot of Corps of Engineers work post-Allison. The place I first lived in for a bit had been flooded up to the 1st floor ceilings during Allison. That area did not flood this time around. Whether that can be attributed to work on the bayou I can’t say.)

I only had to contend with many small lizards who took refuge on my 2d floor patio. When I sat out there after the storm, I felt like I was at a casting call for a Geico commercial.

Thank you to all who contacted me via various channels to inquire about how I was faring. I am deeply grateful, and am glad to say that unlike so many others, I was mainly inconvenienced, rather than suffering bodily or material harm. I am deeply sorry for those less fortunate than I: there but for the grace of God . . .

As I told most of those who wrote, the impacts were highly variable, and largely driven by proximity to the bayous. Or as Beldar, who returned from a long blogging hiatus to write about Harvey put it, there were highly localized but widely distributed areas of impact. In the areas that it was bad, it was horrid. But the bad areas were not as ubiquitous as viewing the news would suggest.

As some commenters have noted, and has been widely recognized, Houston and Texas have acquitted themselves very well. The contrast with the New Orleans during and post-Katrina is remarkable on every dimension. Rather than social disintegration, there has been solidarity and a spirit of mutual aid. My tennis coach’s father works with Red Cross, and says that they have more volunteers than they can handle. The lines in grocery stores that I visited once they reopened were amazing placid, with people patiently chatting while waiting their turn. Would that Christmas shopping scenes be as civil.

But of course, numerous people of ill will outside of Houston and Texas have taken this opportunity to take swipes at the city, state, and their people. Examples include a disgusting “cartoon” in Politico (a Tweet of which the gutless bastards deleted when called out on it), an even more disgusting cartoon in Charlie Hebdo, and more Tweets than I could count claiming that Harvey was divine justice for Houston’s petrol-chem industry–presumably these were Tweeted from artisanal wood and hemp smart phones by people who don’t drive, eschew all plastics, and produce all their own food using only llama dung as fertilizer. (The Unabomber was an evil bastard, but at least he lived what he believed.) These criticisms make as much sense as fundamentalists blaming earthquakes in the Bay Area as God’s retribution on sodomites (which is an illustration of how political opposites are often doppelgängers).

To which most Texans reply: we really don’t give a shit what you think. Or as one meme put it: Hold our beer–we got this.

And of course there are those who are using this to advance their political obsessions. I’ve already mentioned those who assert, obnoxiously and ad nauseum, that Harvey was the inevitable and predictable result of climate change. Among the most prominent, and certainly most execrable of these, was one-time economist Jeffrey Sachs:

Gov. Abbott, we would like to bid you a political adieu. Perhaps you can devote your time to rebuilding Houston and taking night classes in climate science. Senators Ted Cruz and John Cornyn, you will soon be asking us for money to help Texas.

My answer will be yes, if you stop spewing lies about climate dangers, agree to put US and Texas policy under the guidance of climate science, back measures to lower carbon emissions and stay in the Paris Climate Agreement. Then, of course, let’s help your constituents to rebuild.

And to ExxonMobil, Chevron, Koch Industries, ConocoPhillips, Halliburton, and other oil giants doing your business in Texas: You put up the first $25 billion in Houston disaster relief. Call it compensation for your emissions. Tell the truth about growing climate threats. Then, as citizens seeking the common good, we will match your stake.

This is the rankest opportunism, and his entire piece is written with a reckless disregard for the evidence about the link between CO2 and hurricanes generally (which is equivocal at best), and about the link between anthropogenic effects on climate and Hurricane Harvey in particular.

As I noted in my earlier post, Harvey was not an exceptionally powerful storm by historical standards, and indeed storms of its intensity were actually more common during the period prior to large increases in CO2 emissions. Harvey’s devastating effects were a result of the chance interaction of weather patterns that led Harvey to meander and linger over Houston.

At present another hurricane–Irene–is forming in the Atlantic. To illustrate the role of weather, there are two scenarios for its track. If the dominant weather pattern over the North Atlantic is a strong high pressure region, it will likely hit the US, most likely Florida. A weaker high pressure area, will result in Irene turning north and petering out in the Atlantic.

The other hobby horse being ridden with abandon is that Houston’s pro-development policies increased the damage: I’ve read that Houston’s lack of zoning bears some of the blame. Two of the most strident advocates of this view include The Economist and Bloomberg Business Week.

Well, on one level, this is Captain Obvious DUH territory: no development, no damage. More seriously, it is difficult to see how any policy change would have had an appreciable impact. The Houston Has No One to Blame But Itself litany wreaks of the correlation-causation fallacy, and post hoc ergo propter hoc arguments.

Where to begin? I guess with the fact that this was truly an exceptional storm, with record rainfall. Given Houston’s topology and geography, there would have been massive flooding even had the place been inhabited by Karankawa and the Akokisa indians living in grass huts sleeping on chickees, as it was once upon a time.

Houston is flat as a table. It is cut by numerous bayous and streams: its nickname is “The Bayou City.” Many of these streams are quite winding, which means that when they take on a lot of runoff, the water goes up and over the banks rather than rushing out to Galveston Bay, because it has nowhere else to go.

Yes, the pavement and building increases runoff. But several factors need to be kept in mind. First, Houston’s soil is sandy and its water table is very high, meaning that even absent parking lots and streets and buildings the capacity of the soil to absorb is limited. Second, contrary to the prejudices of people who write about Houston in blissful ignorance of the facts, Houston has the largest amount of green space of any city in the United States. Only about 10 percent of the area in Houston is rated as impermeable, and 90 percent is ranks less than 2 on a 5 point scale of permeability (with a lower score indicating greater permeability). Third, many of the outer lying areas that flooded were inundated by the Brazos River and connecting streams, which is another meandering stream, and which was not swollen by runoff from suburban developments, but which just couldn’t handle all the rain and the runoff from undeveloped areas.

And can anyone honestly say that any of Harris County would be that much less developed under any alternative development policies? Zoning for instance, might have affected the distribution of business and maybe some residential areas, but the total amount of the county that would be built on would almost certainly be virtually the same.

Yes, if Houston had adopted the policies of Detroit, and suffered the same economic shocks, there would be a lot more green space and Harvey would have done a lot less damage. No serious person considers that a good trade-off.

Indeed, there have been floods as extreme and even more extreme, back when Houston was far less developed than today. A good example is 1935, when Buffalo Bayou crested at 54 feet. It crested at a mere 40 feet in 2017. But downtown Houston has flooded ever since there was a downtown Houston, because downtown Houston lies hard up a flood-prone bayou. And it was put there because that bayou was the city’s economic link to the world, and which eventually made it one of the great ports in the United States.

In sum, given the prevalence of floods before the boom of the recent decades, it is difficult indeed to attribute this week’s floods to that boom. Instead, the floods are a constant, as is Houston’s geography and topology. Combine those with biblical rains, heavy even by Houston standards, and we have what we have.

Some–The Economist for example–blame permitting of houses in 100 year flood plains. The impact of this (the magazine estimates 8600 houses so located) on the total volume of flooding is certainly trivial, meaning that there are no external effects to speak of. Those who built in these locations assumed the risk, based on the same information The Economist used to make its calculations.

Yes, to the extent that such development is encouraged by subsidized flood insurance, or the prospects of post-flood government assistance, too many of such houses are built, and the private losses are socialized to US taxpayers at large. I completely agree with the principle of making people bear the full cost of insuring the risk, or the full cost of losses if they choose to build but underinsure. But again, the contribution of this to the magnitude of the flooding is probably too small to even measure: the magnitude of the flooding was due to record rain and Houston’s topography. Further, it also likely represents a small fraction of the estimated $160 billion in damage from the storm.

Jeffrey Sachs writes: “Houston has been growing rapidly without attention to flood risk.” It has been growing rapidly, but to say that this growth has occurred without attention to flood risk is a damnable lie–a libel, actually. Especially post-Allison (in 2001) there has been an effort to reduce the city’s vulnerability to flooding. Of course, as with any government endeavor, one can criticize the execution, and the priorities: as commenter and friend Tom Kirkendall notes, money squandered on sports stadiums and light rail (the lightest aspect of which is ridership) could have been better spent on infrastructure, including drainage improvements. But there has been considerable attention. There has been work on the bayous. (For example, there has been ongoing work on Brays Bayou near Calhoun for some time–and the crews were back at work on Friday.)  Moreover, as any Houstonian with a car can tell you (and that is the vast majority of Houstonians, as many outsiders often snarikly remark), every road repaving project is a long running saga because in addition repaving, the city is installing huge storm sewer lines. Shepherd has been a nightmare for years because of such a project.

If you look at the 2011-2015 Houston capital improvement plan, which sets out the various major road projects, you will see that almost all of them include “improving drainage.” There are 27 references to this in the document.

The strategy has been to try to direct runoff to the major highways, which is one reason for some of the most striking images of the flooding. Better to flood freeways than neighborhoods.

So Jeffrey Sachs, in his lofty and deliberate ignorance, can fuck right off.

The rainfall in Harvey was approximately double that of Allison, and covered a much wider area. For example, one reason that some of the major disasters Harvey caused did not occur with Allison is that the former storm overwhelmed the Addicks and Barker Reservoirs, whereas that did not happen with the latter because the heavy rain area did not extend that far.

I do not know for certain, but it is my impression that the Harvey flooding in the area that Allison also hit hard is comparable to what happened in 2001, despite the fact that Harvey’s rainfall was about double Allison’s. A comparison of 2017 and 2001 will tell a lot about how well post-Allison infrastructure changes mitigated the damage this time around.

Post-Allison, the Harris County Flood Control District put out an excellent report on the storm, and its effects. It was titled “Off the Charts” to indicate how exceptional Allison’s rains were. Since Harvey’s were about double Allison’s, off the charts doesn’t even come close to describing 2017.

No doubt HCFCD will put out a post-Harvey report, and will be challenged to come up with a appropriate title. I look forward to reading it, paying particular attention to what it has to say about the effect of post-Allison mitigation efforts.

But the basic point is that this is not primarily, or even secondarily a policy issue, regardless the attempts of opportunists to make it so. This was a historic storm–an epic storm–produced by a chance interaction of weather events. It dumped huge rains on one of the largest cities in the US–in amounts that would have no doubt overwhelmed every major city in the US. Moreover, it hit a city which nature made preternaturally vulnerable to flooding.

In sum, Harvey is a natural disaster. The economic cost is indeed due to economic development, but that is primarily an effect, rather than a cause, as Jeffrey Sachs, the Economist, Bloomberg BusinessWeek and myriad others with an axe to grind would make it.

Musical postscript. I survived Harvey’s danger, and didn’t even have to climb a flagpole.

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