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Author Topic: 8/21/2021 Waverly Flood Disaster  (Read 4896 times)

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Offline Thundersnow

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Re: 8/21/2021 Waverly Flood Disaster
« Reply #45 on: August 22, 2021, 11:06:06 PM »

Online Bruce

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Re: 8/21/2021 Waverly Flood Disaster
« Reply #46 on: August 23, 2021, 07:54:47 AM »
https://youtu.be/WJX_uCOUHZk
simply gut wrenching seeing pics and vids coming in… all my In laws live Waverly … thank god all is good for them they live on the ridge part off 13…   If things go as planned I will be up there this upcoming weekend to help support needy families whatever I can do. A lot cleanup ahead .
BRING ON SEVERE WEATHER SEASON..

Offline Thundersnow

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Re: 8/21/2021 Waverly Flood Disaster
« Reply #47 on: August 23, 2021, 08:26:07 AM »
For it to be that intense something along the creek or river had to fail or collapse, right? I can’t imagine that amount of water rising that fast without some sort of failure

Good question.

I'm looking at the topo map of that area. It's an east-west flowing creek that empties into the TN River/KY Lake not many miles to the west. It appears to be a fairly steep valley with ranges of hills with side tributaries flowing out of the hills from the north and south. I'm no expert on any of this by any stretch. But, I just wonder if the drainage area just hit a tipping point. The throughput of the creek hit a wall when it reached a certain level before flowing out into the lake, and it wasn't able to as efficiently eject the extra water, as the heavy rainfall slammed all the side tributaries with massive volumes of water which all quickly emptied into the valley that Waverly sits in.

That's just an amateur guess.
« Last Edit: August 23, 2021, 09:13:58 AM by Thundersnow »

Offline Thundersnow

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Re: 8/21/2021 Waverly Flood Disaster
« Reply #48 on: August 23, 2021, 08:37:41 AM »
This tragic and historic event deserves its own thread. So, I have split it off from the August thread.
« Last Edit: August 23, 2021, 09:14:31 AM by Thundersnow »

Offline schneitzeit

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Re: 8/21/2021 Waverly Flood Disaster
« Reply #49 on: August 23, 2021, 08:40:27 AM »
Does anyone know of a way to donate to the folks affected?

Offline dwagner88

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Re: 8/21/2021 Waverly Flood Disaster
« Reply #50 on: August 23, 2021, 08:52:02 AM »
Good question.

I'm looking at the topo map of that area. It's an east-west flowing creek that empties into the TN River/KY Lake not many miles to the west. It appears to be a fairly steep valley with ranges of hills with side tributaries flowing out of the hills from the north and south. I'm no expert on any of this by any stretch. But, I just wonder if the drainage area just hit a tipping point. The throughput of the creek hit a wall when it reached a certain level before flowing out into the lake, and it wasn't able to as efficiently eject the extra water, as the heavy rainfall  slammed all the side tributaries with massive volumes of water which all quickly emptied into the valley that Waverly sits in.

That's just an amateur guess.
I was looking at this on Google Maps today. The headwaters of Trace Creek are in McEwen where the highest rain totals were recorded. McEwen actually straddles two watersheds. The north side of town drains to Waverly, the south side towards Hurricane Mills and the Duck River. Hurricane Mills was also hit with horrible flash flooding, but it's a more sparsely populated area. The watershed appears to choke down around Waverly. It is actually far more broad up near McEwen. That natural choke point led to a worst case scenario for flash flooding. That also explains why the water rise was reported to be so rapid, and why the damage looks like a tsunami.
Winter 2009-10 Snowfall: 11.5 in. :)
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Winter 2012-2013: 0.25 in.
Winter 2013-14: 10.6 (9.5 on 2/12)
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Winters 2015-2019: basically nothing
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2/8/20: 4.25

Offline Thundersnow

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Re: 8/21/2021 Waverly Flood Disaster
« Reply #51 on: August 23, 2021, 09:11:50 AM »
I think you're right. I believe that feature of higher elevation east of the River is Tennessee Ridge. The creeks basically squeeze through that, which bottlenecks the runoff.

Offline Beth

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Re: 8/21/2021 Waverly Flood Disaster
« Reply #52 on: August 23, 2021, 10:30:48 AM »
One of the citizens that lives in Waverly said that Rust Creek use to be a deep creek. But that the last 40 years it started to fill up with rocks, trees and other debris. Unfortunately nothing had been put in place to dredge it out.  I am sure it will now.
Our Church in Dickson is Compassion Church And they are taking enormous amounts of supplies to Waverly in tractor trailer trucks.  The Citizens are begging for heavy duty machinery to lift the debris to find their loved ones. 
If you want to donate to this disaster our Church has a link but also You can google Waverly TN disaster relief.
One of my daughter’s close friend lost her toddler. He was swept away like so many others. He has not been located. 
But Tennessean’s are doing so much to help.  We are the Volunteer State.  If you are a Praying person then please pray that lost loved ones can be found and families can have closures.  Dickson got hit pretty hard to but nothing like Waverly.  Our Schools are closed today as so many roads were torn up from the flooding here.  But we were very lucky and had no water issues.

Offline Thundersnow

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Re: 8/21/2021 Waverly Flood Disaster
« Reply #53 on: August 23, 2021, 10:17:42 PM »
I heard an explanation for the rapid nature of the flood in those neighborhoods.

It seems that there was a bridge upstream that created a damming situation with debris that washed into the upstream side of it, forming a temporary reservoir of flood water. The mass gave way and collapsed, sending the wall of water crashing downstream.

Offline StormNine

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Re: 8/21/2021 Waverly Flood Disaster
« Reply #54 on: August 24, 2021, 08:05:39 AM »
I heard an explanation for the rapid nature of the flood in those neighborhoods.

It seems that there was a bridge upstream that created a damming situation with debris that washed into the upstream side of it, forming a temporary reservoir of flood water. The mass gave way and collapsed, sending the wall of water crashing downstream.

In some of the pictures, you can see the debris along that bridge. Similar to the Blanco River situation in TX (2015) and some of your western floods just having a narrower channel, in general, helps max out the already powerful force that water has because it is occurring over a smaller surface area. Just like you would rather get hit with a regular tennis shoe upside your head versus the point of a high-heeled shoe.  The force is spread out more evenly over the area of the tennis shoe versus the high heels.       

There is actually some gradient from about 850 ft near McEwen to around 550 ft to Waverly that is enough to probably make some difference as well.

At the end of the day getting 17 inches in 6 hours is just going to make a bad sitaution for pretty much anyone.   

Offline Thundersnow

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Re: 8/21/2021 Waverly Flood Disaster
« Reply #55 on: August 24, 2021, 08:37:08 AM »
To further elaborate so this even makes more sense, it was apparently a railroad bridge where the event occurred. The railroad grade/train track is elevated. When the crossing over the creek was blocked, the track ridge actually behaved like a levee, which contained floodwaters backing up behind the railroad crossing. When the blockage at the railroad bridge broke loose, it truly was like a dam broke.
« Last Edit: August 24, 2021, 08:56:27 AM by Thundersnow »

Offline Nash_LSU

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Re: 8/21/2021 Waverly Flood Disaster
« Reply #56 on: August 24, 2021, 08:43:53 AM »
To further elaborate so this even makes more sense, it was apparently a railroad bridge where the event occurred. The railroad grade/train track is elevated. When the crossing over the creek was blocked, the track ridge actually behaved like a levy, which contained floodwaters backing up behind the railroad crossing. When the blockage at the railroad bridge broke loose, it truly was like a dam broke.

Here is some drone video of said railroad bridge. https://www.youtube.com/watch?v=aAhL91FRnAk

Offline Charles L.

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Re: 8/21/2021 Waverly Flood Disaster
« Reply #57 on: August 24, 2021, 10:09:43 AM »
To further elaborate so this even makes more sense, it was apparently a railroad bridge where the event occurred. The railroad grade/train track is elevated. When the crossing over the creek was blocked, the track ridge actually behaved like a levee, which contained floodwaters backing up behind the railroad crossing. When the blockage at the railroad bridge broke loose, it truly was like a dam broke.

That is almost exactly what happened, to the detail, in Sumner County several years ago
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Offline joemomma

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Re: 8/21/2021 Waverly Flood Disaster
« Reply #58 on: August 24, 2021, 11:56:42 AM »
Maybe I missed it, as I haven't been following weather very closely of late, but where did all this rain come from? 

Offline Thundersnow

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Re: 8/21/2021 Waverly Flood Disaster
« Reply #59 on: August 24, 2021, 01:22:34 PM »
Maybe I missed it, as I haven't been following weather very closely of late, but where did all this rain come from?

A boundary was stalled over western Middle TN in a very humid air mass, which was the focus for continuous and training thunderstorms for several hours.

Someone else might come in with a better meteorological explanation.

I will say that I noticed at the time that Henri was out in the Atlantic moving northward toward the Northeast. I was wondering at that time if it could have been an indirect factor and put the breaks on features moving through the US. A Bermuda high or ridge to the east can do that too, though.
« Last Edit: August 24, 2021, 01:58:34 PM by Thundersnow »

 

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