This is going to be another one of those “unless you’ve just crawled out from under a rock” posts, because that’s about the only way you wouldn’t be submerged in coverage of Hurricane Harvey and its aftereffects on the Houston region in Texas. If you thought Noah was just a Biblical character and the story of the Ark simply a parable, imagine what 40 straight days and nights of rain could do…less than a week’s worth dumped over 50 inches on some hapless portions of Texas.
Anyway, there’s an estimate that Houston was bathed in nearly 20 trillion gallons of water, and if I recall my formula correctly a cubic foot holds roughly 7 1/2 gallons – thus, an area of 2.6 trillion square feet would have been submerged one foot deep. In turn, that works out to an area 1,632,993 feet on each side, which equals 309 miles – 95,653 square miles, to be exact. Imagine not just Maryland and Delaware under a foot of water, but all of Pennsylvania and the majority of Virginia as well. Put another way, under that same deluge all of Maryland would be drowned beneath about 10 feet of water.
What make this relevant is an article written by Jon Cassidy in the American Spectator that I came across. When people talk about planning it piques my interest for obvious reasons: architecture is my chosen profession, but I know just enough about land planning and civil engineering to be dangerous – one area I learned a little bit about in the position I have now (albeit when I had my first bite of the apple a decade ago) was the technique required for doing stormwater management and other civil work. Coming here from Ohio I found out stormwater management is a BIG f’ing deal in Maryland, much more so than in my home state.
This is important because the blame for the extreme flooding in and around Houston is being placed on the rampant growth and large amounts of impermeable surface in that area. But, as Cassidy writes, development is many orders of magnitude shy of being the primary cause:
The idea that pavement is to blame for Houston’s flooding is, to put it simply, idiotic, even comical. The daily journalists on their deadlines haven’t had time to realize how out of their depth they are, but the (Texas) Tribune has no excuse for its shoddy reporting. The committees that awarded those prizes should be ashamed of their inability to spot the obvious hole in the narrative, which has been there all along.
The turf surrounding Houston is not, in the words of the county official the Tribune singled out for abuse, a “magic sponge.” Yes, it absorbs some water. Yes, of course, impermeable surfaces produce runoff. But no, absolutely not, no way, no how, could the clay and sandy soil around Houston have absorbed this deluge. The poor absorptive capacity of our soil is a matter of record, but that didn’t really matter. Even if our turf had the absorptive capacity of the Shamwow, Hurricane Harvey would have overwhelmed it.
A study by the Harris County Flood Control District, which focused on the same Cypress Creek region that interested the Tribune, found that a residential development with 50 percent impervious cover would indeed absorb less water, creating more runoff. To be precise, the development would absorb exactly 1.79 inches less rainfall than an undeveloped property. But we got hit with up to 51.88 inches of rain during Hurricane Harvey. That’s more than rainy Seattle got all last year.
So even if the Tribune had had its anti-development agenda fully realized, it would have made no difference. The soil would have absorbed the first couple inches of rainfall, and the next 50 inches still would have had to go somewhere. Back in 1935, when the area was almost entirely covered by natural wetlands, it still got flooded.
Cassidy has an unlikely ally in Charles Marohn, the creator of a website called Strong Towns. (It’s often cited by the mayor of Salisbury, who seems to be an advocate of so-called “smart growth.”)
Harvey is not normal times. We can’t look at this event the way we look at other flooding events. The devastation in Houston from Hurricane Harvey is not the result of the accumulation of many bad decisions. It was simply a huge storm.
The Texas A&M research I highlighted above suggests reckless wetland filling robbed Houston of 4 billion gallons of stormwater storage capacity. For context, the Washington Post is reporting now that Harvey dumped 19 trillion gallons on Texas—a large portion of that hitting the Houston area. That means that, had those wetlands never been filled, they could have accommodated at most .02-.1% of the water that fell in Harvey.
Exactly. Soil has a carrying capacity of drainage, and some soils drain better than others. If you’ve spent any amount of time in Florida, you’ll know it rains nearly every day but the soil drains quickly because it’s quite sandy. Places with a lot of clay, though, aren’t as fortunate. To manage stormwater, the common technique involves collecting the overflow from impermeable areas and placing it in retention ponds where it can be released for drainage in a controlled fashion. It’s why you often see bodies of water along roads, highways, and inside developments – they’re not necessarily there for looks, but as catchbasins.
Of course, not every area has managed stormwater and in times of extreme weather they flood. During Superstorm Sandy in 2012, a large part of downtown Salisbury flooded, causing damage to several buildings. Other parts of town are often under water after a heavy rainfall of 4″ or more, with one significant headache being the closing of Business Route 13 at its intersection with Priscilla Street, adjacent to a large pond.
But even the best techniques would fail under a deluge like Harvey, and that’s the point. We design for 10- and 100-year flood events, but it’s prohibitively expensive and, frankly, unnecessary to worry about 500- or 1000-year events like Harvey may have been. Those cases are truly acts of God and the best we can do for those is pray for minimal loss of life. We can rebuild a building, but we can’t get the 30-odd victims of Harvey back.
Back to routine: Here at this residence, we’re getting set for one last school year. With the distractions of summer over, it will finally be time for me to get serious about writing once again. While it’s looking more like a wrap by the middle of 2018 rather than the spring, I’m still thinking I have a good start on The Rise and Fall of the TEA Party, and with recent developments there may be an entirely new hook to expound upon as I increase the word count.
So I haven’t forgotten. However, I also want to get a little bit into the 2018 campaign and perhaps get back to doing this blogging more often than a couple times a month. We will see.
But the year of my discontent seems to be closing – not that I miss being politically active, but going forward I’m not going to studiously avoid it, either. (I will miss the WCRC Crab Feast, though, but only because my grandson’s first birthday is being celebrated that day. Family first.) If nothing works its way onto my calendar for that Saturday I might make the Lincoln Day Dinner in October.
So that’s a brief update. All those impatient because I do other stuff besides politics may get their wish as baseball season winds down.