Flash Flood Warning
20041118
We see flash flood warnings all the time, whenever it rains hard. And the news people feel compelled to show scenes of stupid people climbing out their car windows into water up to the door handles. And cars being swept away, down the river that used to be just down the street. And they tell us how many people died last year from drowning in flash floods. On the news tonight were stories and videos of rescues from the raging rivers. On the one hand, sort of in defense of some people, one of the rivers rose -- ready? -- eleven feet in two hours. That is one inch per *minute*. Those stories were followed by the videos of trucks and SUXs driving through water up to the middle of the doors. And the police arresting them either on the other side of the river or after they'd been rescued downstream. Turns out that the police must actually observe the driver going around the barricades in order to charge him or her with the Texas version of reckless endangerment which is "deadly driving." And there were at least two of those charges today. How can you possibly do that while the cops are watching? Let's see, there's a raging torrent where the road used to be, and there's a police barricade here designed to keep me from driving into that raging torrent where the road used to be, and there's a cop car just sitting here with his blinkers on to warn people not to drive around the barricades and into the raging torrent where the road used to be. I think I'll drive around the barricade and see if I can get across the raging torrent, or maybe turn my new car into a boat and have an adventure. Must be many, many stupid people.
Well, as of this morning, I have a new respect for flash flood warnings that I didn't have yesterday. Two incidents. I knew that I had gotten stupider down here, but I was not aware just how much. When I looked out the window this morning, I noticed that Lake Spicewood, that's our name for the playground of the elementary school behind our yard, was as large as I have ever seen it. We are at about the highest point in the county, a thousand feet above sea level, but hard rain fills the local low spots with puddles like anywhere else, made slightly worse here by the ground, which is solid limestone almost up to the surface but covered in places with inches or feet of impervious icky clay. So when it rains, we have the Alpine Lakes of Central Texas in the schoolyard next door.
One. Driving along a perfectly normal suburban road, past the Exxon and the Wendy's, there is a little curve to the left. And there is a little puddle. And suddenly, the car is half a lane over to the right. Instantly, no warning. Had there been someone there, I would absolutely have pushed him out of the lane. Oops. Hydroplaning at a mere forty miles an hour? Hmmm. Should have imbued greater caution as I continued on.
The road construction in the area has changed the landscape so much that there are now lakes and rivers where there used to be just fields. I drive past one temporary lake in a construction area, about a two hundred feet wide and two thousand feet long, and all right up at road level. At the end of the lake, there is a smallish river running across the road to the arroyo on the other side. Boy, that'll be fun to work in tomorrow. I think they should probably put in a flume there as part of the reconstruction.
Digression: Impervious cover in Houston and Austin.
A big box store moves into your neighborhood. Jobs, more shopping, signs of prosperity, right? Sometimes that depends on criteria that few consider in advance. What's the contour of the land between that store and you? Is it uphill from your street?
A single large store moves in, paves over five to ten acres for building and parking lot. A small mall, twenty to thirty acres. A large mall, more than that. A few million square feet of concrete where there used to be grass. Impervious cover. Rain doesn't penetrate it and sink into the ground. It flows off, downhill, somewhere else. Away. Not our problem. It flows off our property. Somebody else's problem.
Well, if you're the place downhill from that concrete pad, your experience of rain changes. Your house is above the hundred-year flood plain? Well, it used to be. The house didn't move; the drainage pattern did. My brother's house was at the top of the hundred-year flood plain, by only inches, but above. Twenty years later, it seemed to be in the five-year flood plain. Works like this:
". . . the total runoff volume for a one-acre parking lot is about 16 times that produced by an undeveloped meadow. . . . The peak discharge, velocity and time of concentration of stormwater runoff also exhibit a striking increase after a meadow is replaced by a parking lot." (Center for Watershed Protection)
Zoning boards and planning commissions should pay a little more attention to this problem and its impact on downstream neighborhoods. In the case of my brother's neighborhood, the city of Houston has bought the entire area, every single house, so that they can widen the bayou to prevent even more flooding further downstream. Huge new big box stores and malls a mile to two north. But no more houses full of shoppers.
End of digression.
Two. I thought that the underpass coming up in a mile or so would be bad, but surprisingly it isn't. Dry, no puddles at all. A wonder of drainage engineering. Then I come up out of the underpass and start up the little hill beyond it. The pickup in front of me is driving through this puddle -- what's a puddle doing on the side of a hill? -- putting up big rooster tails. But the water isn't even over the rubber of his tires. I mean, how deep can it be on the side of a hill? On a nice, flat road? No problema. So I go through, too. For the next hundred yards, I'm driving through a river flowing sideways across the road. Obliquely, not perpendicular. What's a river doing on the side of a hill? This is a new river flowing toward me down the shoulder on the left side, then it crosses the road here to flow into the construction ditches on the right side. It's only, oh, four or five inches deep. But it's flowing like crazy, completely across the four lane road in one to two seconds, which according to my arithmetic in a later moment of clarity is like twenty miles an hour. Several times faster than I'm going. I have to slow to a crawl to make headway and steer at the same time. If you hydroplane on this stuff, you end up off the road completely, faster than you can react.
In the rear view mirror, I see another pickup behind me enter the river. Too fast. The pickup is covered with a wave, sploosh, inundated, it disappears completely, then the water flows off and he slows down. Not enough, he still goes too fast, putting up a much larger wake than I was, but he makes it.
Digression: I hope he had his window closed. Back when I smoked, I always drove with the window cracked for ventilation, to draw out the smoke, and as a place to flick ashes. At least when I wasn't driving in desert areas like California. Out there in the land of brush fires, you don't dare flick an ash much less a cigarette butt out a window. One learns to use ashtrays, a skill that is not part of the Northeasterner's training regimen. I even had to reject a rental car once in L.A. because it didn't have an ashtray. But that was back in the dark days before I had my brain washed at Mass General and denied the Demon Nicotine.
In the early days of driving and smoking, there was the little front vent window, the triangular forward tip of the front window that pivoted on a vertical axis, right at the smoking driver's left hand, which was incredibly convenient for smokers. Just pop the window open half an inch, the draft sucked the ashes right off the end of the cigarette, didn't make much noise, didn't create a large draft. What draft there was was outbound, so that even in the middle of winter you didn't have an icy breeze cryogenically preserving your left ear. Just turn up the heat a little to compensate for the loss. Similarly for air conditioning in the summer.
Aside: sunroofs are good for this sucking and flicking, too, but they're awfully noisy by comparison, and they really suck the heat out of the car in winter and kill your air conditioning in the summer.
But then in an effort to streamline and lighten (and cheapen) cars, the manufacturers killed the little vent windows. Cars were made to run with the windows shut all the time. Use the ventilation system if you want fresh air. They all come with A/C these days, so no problem even in summer. If you wanted to draw the smoke out so that it didn't stink up the interior, however, you still had to crack the window. Then you really did have the cryogenic, or fry-ogenic depending on the season, process working on the ear. See all the fun that you non-smokers missed out on? So you drive around with the driver's window cracked a few inches so you can flick the ashes out and have the wind suck them away. Or, if you really don't like the guy on the motorcycle behind you, flick the whole cigarette.
In the rain, this became a problem. If the rain was coming from the wrong direction, you couldn't really keep the window open all the time. So you crank it down an inch, flick, crank it up an inch. Pain in the butt. And all to keep other people from complaining that your car stinks. At the time we didn't know about secondhand smoke. ("Smoking is so dangerous that it kills people who don't even do it.")
So, one day (Get to the point already, geez!) I'm driving along with the window open, oh, maybe four or five inches. The rain has stopped or at least slowed to a drizzle. But then there's this puddle. I go through it, no problem. It's the truck going the other way that's the problem. He throws up a huge wake on both sides. Uh oh. I see it coming just a second before the truck-nami hits. No time to roll up the window, only enough reaction time to get a hand up. And that was really ineffective at warding off the gallons of muddy water that shot the gap into my face, hand, arm, neck, shirt, jacket, the entire front interior of the car. What a delight.
I hope he had his window closed. End of digression.
On the other side, I pass two SUXs stopped on the side of the road. They're looking at the flood, watching me and the pickup ford the stream. But there's no traffic coming the other way. A mile up the road, I see the police diverting all traffic on that side to another road that goes around the trouble. They haven't done my side yet, don't know why. Maybe it's worse driving downstream, as they would be doing from that direction. Yes, that's it. Driving against the current, you can still steer; but with the current, you can't. I remember this from days on a friend's sailboat: beware tides that flow faster than you can make headway.
This incident was an eye-opener. In the future, I think I will make U-turns instead of trying to drive through this sort of innocent-looking stream. Better a dry chicken. But today there were many, many stupid people plus one.
Copyright (C) 2000-2004, Richard Ball Landau. All rights reserved.
