Posted on 08/29/2017 10:17:42 AM PDT by Mechanicos
A city engineer was explaining on television yesterday that the levees are required to be designed for a 100 year flood (Federal requirement), and that a design margin was added to that when the levees were designed.
However, TV weather people are calling this a 1000 year flood (that is, a 0.1% chance of occurring). That is, the current rainfall is way over the 100 year amount.
My take on this: With all of the paving that has been added in the past four decades as the community has expanded in every direction, the amount of runoff and the speed with which it runs off have increased for any given amount of rainfall. It can’t soak into the ground, and the speed of runoff is higher for concrete than it is for grass or dirt. Levels rise faster and higher for a given downpour. So a river level corresponding to a 100 year downpour of 30 or 40 years ago would tend to happen more frequently today.
One weatherman said that there have been four 1000 year floods in Texas and Louisiana in the past four years. Obviously, the data used to determine what constitutes a 1000 year flood (or a 100 year flood) is out of date for the Houston area. That being said, the current storm has dumped a lot more water on Houston than could reasonably have been proposed as a design basis for the levees. It’s not just the inches of water rainfall, but the area over which that rainfall fell at the same point in time. The total volume of water which must be handled is higher than could have been anticipated.
In the Houston area INCHES matter. Even a few trees can make a disaster. We lived near Oyster Creek when we first moved to Houston. In 1989 some storm came through and water rose steadily to our first step then second step from the street and curb. It was just about an inch from entering the house. The reason? construction debris in a new development just down stream were blocking some of the drainage. The drainage district channelized the drainage and we never saw water that high again in the 6 years we lived there.
I’m sure glad we are gone from that place in First Colony.
Bttt.
Prayers up for TX.
5.56mm
Where’d that article come from, please?
Led Zeppelin. Now Bob Dylan:
Crash on the levee, mama
Water’s gonna overflow
Swamp’s gonna rise
No boat’s gonna row
Now, you can train on down
To Williams Point
You can bust your feet
You can rock this joint
But oh mama, ain’t you gonna miss your best friend now?
You’re gonna have to find yourself
Another best friend, somehow
Now, don’t you try an’ move me
You’re just gonna lose
There’s a crash on the levee
And, mama, you’ve been refused
Well, it’s sugar for sugar
And salt for salt
If you go down in the flood
It’s gonna be your own fault
Oh mama, ain’t you gonna miss your best friend now?
You’re gonna have to find yourself
Another best friend, somehow
Well, that high tide’s risin’
Mama, don’t you let me down
Pack up your suitcase
Mama, don’t you make a sound
Now, it’s king for king
Queen for queen
It’s gonna be the meanest flood
That anybody’s seen
Oh mama, ain’t you gonna miss your best friend now?
Yes, you’re gonna have to find yourself
Another best friend, somehow
Authorities make us buy cars with seat belts, airbags, etc., forcing us to use them for our own good. So if city officials are kicking the can down the road by not preventing floods in a flood plain, why not create legislation that mandates that every house must have an inflatable boat attached to the upper part of the house, akin to life-rafts on ships. After all, we already have to have smoke detectors, CO2 detectors and water heater bracing (here in California) among other items. I have an inflatable boat, although I've never seen a flood, but they're cheap. (Written in jest; be aware of the dangers where you live!)
Was reading elsewhere that Houston has sunk 10 feet or so since the 1920's. That can't help when inches matter. And the city is still sinking a couple inches every year.
I grew up in Buffalo. I didn't know anything about a levee. We just had to deal with snow. Water is a far more dangerous situation.
My son went to Tulane. After Katrina, when I took him back to school, I couldn't believe the destruction.
Prayers for the good people of Houston and Texas.
A little further west is Old Ocean where a major refinery is located.
There’s a reason the Indians didn’t have permanent settlements on the coastal plains of Texas.
oops! post #26
And Trump is in Texas. I bet he blew it up.
(How long before someone in the media or Twitter says that?)
I’m not seeing more on this, either FR or on the news. Is this real, or all that serious? I’d think I’d be seeing FOX going nuts over this.
Yes... it was a real story... but, it ended pretty quickly. THIS happened:
OMG!! I was driving to Frankfort today, and was listening to FoxNews. They sent a reporter to Columbia Lakes to check out the “levee breech”. Instead of finding a bunch of fleeing people, they found a bunch of locals with backhoes, bags of sand and bricks... with poles, planks and guts. They had “repaired the breech”. The reporter ask if this make-shift repair would hold. His answer?
“Yessir. We’ve made it strong. We got 500 homes in this neighborhood. There not going to flood. Not on my watch!”
LOLOL. Them is MY people!
The link is too the official county twitter account. I suspect they felt a full burst was going to happen but has not yet.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.