Sunday, June 8, 2008

Indiana: Crossroads of Supercells - Our Future?

You probably thought that I had a case of carpel tunnel syndrome after my last lengthy post; The Cubic Mile of Oil, since I have been absent for so long. Unfortunately, nearly all my waking hours since then have revolved around recovering from supercell thunderstorms that have been raking the Midwest. And I have had it easy compared to other Hoosiers.
As I write this, my neighbors in the counties south of here are battling floodwaters the likes of which we have not seen in Indiana since 1913, and some communities have already broken the records from that historic storm. Some counties south of the metro area received more than a quarter of the average annual rainfall in less than 24 hours, with some locations receiving an unbelievable eleven inches of rain. We are becoming used to the images on local weather broadcasts (kudos to the WTHR team coverage) that track multiple chains of severe thunderstorms across our state with the high-tech graphics that show cartoon tornadoes, but on the ground, we are growing weary of the sandbags, pumps, downed trees, power outages, flooded fields, closed roads, evacuated homes, tornado-ravaged communities, ruined personal belongings and mildewed walls.

A truly sustainable green building should be designed for disaster resistance. A building that is easily damaged by the types of disasters that can normally be expected in a particular location is a candidate for the landfill. That is becoming much more challenging in our time of climate destabilization where supercell thunderstorms and the tornadoes and torrential rains they spawn are becoming a weekly occurance across the Midwest.

I currently have a two-foot tall sand-bag dam around the front of my house and gas-powered two-inch discharge trash pump sitting on my front porch. No, I do not live in a flood zone. Living anywhere near a 100-year flood zone or even a 500-year flood zone does not meet my criteria for disaster-resistant site selection. In fact, my Indianapolis neighborhood, Highland Kessler, received its name for the fact that it is a good seventy feet above the White River that attracted early settlers here. Downtown Indianapolis should flood six stories deep before my house does. Unfortunately, when I bought this place in a normally placid wooded neighborhood three years ago, I assumed that the high elevation equated with good drainage, since that would be such an easy engineering problem. For reasons I won't get into in this post, that is not the case and I have been flooded twice in the past two weeks to the extent our paper delivery person had to wade in to delivery my paper (I'm working on her medal recommendation letter) past cars nearly floating in my driveway. The first time I was also cleaning up after a large tree blew over and my garage and crawl space were flooded. The second time I had to deal with even higher water that overturned the contents of my garage, including gas cans and plastic bins of off-season clothing (not a good combination), and got to within a half inch of breaching my front door. These were both storms packing less than two inches of rain, but were of extreme intensity on already saturated ground.
They were supercell storms that generated high winds, golf-ball-sized hail, bizaare lightning frequency, tornadoes and torrential downpours. With a reasonably competent drainage system design, these storms should not have led to flooding in my neighborhood. A neighbor who has lived here for 55 years said she had never seen anything like the flooding this season. My raised-bed garden surrounded by 2x6s nearly floated off in what looked like a mountain stream and the tomatoes are listing. My understanding is that a solution to my local drainage issue is in design as I write this. I hope they sprung for the good engineers.

My greater concern is the larger question: are storms growning generally more severe in the Midwest as climate destabilizes and the Gulf of Mexico warms? Will there be any truly high ground in the future? How can we design for the type of extreme weather we have been seeing lately in the Midwest?

Due to my personal exposure, I have developed perhaps a heightened awareness of this issue, to the point that I check the weather radar about as much as I check my email. Last Friday, I noticed that hundreds of thunderheads were rising off the Gulf of Mexico and rushing toward the vortex of the low pressure system that was headed for Indianapolis. I told a design colleague who specializes in hydrology to go take a look at the national weather radar and see if he didn't share my concern that a major rainmaker was headed for us. I left work early to see if I could scrounge some big pumps and sandbags to save my house from the "big one." I was successful securing pumps and on Saturday I had a crew of extended family gathering sandbags (there were eight sandbags left at the city garage- we had to go to Lowes) and hooking up piping.
The radar showed a now-familiar train of severe thunderstorms headed our way with high winds, potential tornadoes, frequent lightning, hail and torrential rains. About the time we finished our preparations the radar picture showed the storms had tracked mostly to the south of the Indianapolis metropolitan area with disasterous effects. Whole towns in Morgan and Johnson and Bartholomew counties were flooded, as were interstate highways 70 and 65. Hospitals, designed for ultimate disaster resistance for obvious reasons, were taking on water and one had to be closed. The magnitude of the devastation made my predicament seem trivial. Another wave of powerful storms is headed our way on Monday, packing from 1 to 3 inches of rain. Stay tuned.

As for the bigger picture, have a look at the Science Daily story today about the potential relationship between climate destabilization and severe storms that mirrors my concerns. And later came the even more authoritative report by the U.S. Climate Science Program.

Please step over my dam and around the shiny new pump on my front porch. I'm going to leave them there until the 30-day wait for my national flood insurance policy ends and I feel a little less exposed. Perhaps then I will have time to post about how to design for disaster resistance in a world where the old rules of thumb are rapidly changing.

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