Flood prevention
Lets say you live somewhere in the south. Or really, anywhere that could wind up flooding after a Once In 500 Years type flood. Or even an industrial accident, where for some reason your habitat is flooded for a month.
So... how do you keep out the water? And I mean keep it out for about 6 months to a year.
This construction assumes the living space will be higher than the level of the water, but I'm more concerned about the worst case scenario of the land absorbing the water, becoming soggy and it sinking.
What sort of stone, what sort of masonry? Just tons and tons of concrete? Do you need to build beneath the level of the land, or can it just stay on the surface?
>Habitat
That is a weird way to put things, and a weird question. A place that is flooded for six months to a year is a Lake, not a "your habitat"
>>984823
Maybe I like knowing houses I build are good to live through rain, snow, hurricane or flood, pal.
>>984828
>live below sea level
>wooooooooooow why did it flood so bad
>South
They have the Andes. Plus I am sure there are mountains in Africa too. Why would somewhere flood just because it is South?
>>984828
Not your pal, friend.
Properly engineered pilings that descend all the way down to stone (or simply quite deep) incorporated into a monolithic reinforced concrete structure with reinforced doors and windows engineered like massive aquarium segments. Your multi-million dollar surface-bunker might be fine.
On a more "normal" level, a concrete and steel structure, built in the style of a normal home, would serve. Make sure the foundation is as secure as possible, pilings a good choice, and place things like the power box, hvac and water heater upstairs. Don't expect to dwell in the middle of the sewage & gasoline swamp with a boat tied up outside your bedroom window.
I plan to wait for the recurring floods to trash lake lot prices in my local area, and then build a summer cabin on stilts.
I'll have live off culligan jugs of water and everything, including heat, will have to be electric, but whatever.
>>984844
Many of these comments are good, but you wouldn't really need to over design the home, as long as you kept the home away from the surface water (either by building on a small hill, embankments, or sand bagging if you have advance warning) you might be fine.
Catch is, you are definitely going to want foundations below the water table, and you need to thoroughly understand the soil characteristics below the house. A clay with high swelling potential will wreck your shit no matter what, but a decent sand or gravel might work.
Either way, be aware that you aren't getting any money from flood insurance if you fuck it up and don't get a certified engineer to be on board with your design.
![s_m01_14381413[1].jpg](https://i.imgur.com/NAbNo0f.jpg "s_m01_14381413[1].jpg")
>>984808
![article-1388660-0C24806B00000578-130_964x433[1].jpg](https://i.imgur.com/xCnv7A7.jpg "article-1388660-0C24806B00000578-130_964x433[1].jpg")
>>984808
Here ya go muddy buddy.
>>984882
can i know more about the story of this pic?
>>984884
http://www.theatlantic.com/photo/2011/05/mississippi-floodwaters-roll-south/100069/
>>984857
>retard
>implying that still isn't north of the equator
Where was your reference point? Basketball Americans, sheesh.
>>984917
It's south of the wall...
Bona fide southerner here, born and grew up in the delta.
If you live anywhere where people actually had the intelligence and foresight, you'll have levees around your towns and cities.
The biggest trick to this, is maintenance. Mow those levees like they're the yard in front of the county courthouse.
The county courthouse in my home town to this day has stains from flooding and dents from cannonballs during the civil war era, and literally nobody outside of my state knows the towns name.
It's in a flood basin of the Missouri river in the breadbasket. We used to export more rice than China itself.
If you truly want to prevent floods, it's unethical and not at all economic to do it yourself. By all means, prepare and after hell comes, deliver your success to the city officials in a public hearing. Go to city hall after you overcome the next flood yourself. I promise you'll find a lot of angry people there willing to fix the problem so it doesn't happen again.
The old city of mine has flood walls you just can't get around. Ten years ago or so the river was so high, everywhere was flooded in the county but my home town.
I remember swimming in the ditches by the road, they were so deep and culverts so large.
They aren't preppers by a long shot, a bunch of angry old men cracked the whip hard enough for the youngsters to bother using their farm equipment to dig. That's all it takes.
Flooding isn't something just for a home. One household can certainly stand the tideof flooding, like in the pic... but it can't stand the tide of displaced home owners.
If you can successfully fend off a flood on your own property, then you should go to the city hall and demand an enormous project to construct a levee around the entire city.
And, as I said before... I come from a town where levees were built before we were born.
A lot of floods happened after that.
However...
the only solution to flooding is elevation.
IF POSSIBLE, build your home on a plot of land that is elevated a few meters above the 500 year flood level, or the projected sea rise.
Artificial his are possible, but can be very expensive. ( it isnt just tossing dirt on the ground)
>>985018 oops, this is the pic I meant. The other was meant for this post. Anyways...
...And ours remains untouched because of the lessons learned by elder citizens long gone.
If you build a levee, you have to mow the grass on it. You can't let trees or bushes or even shrubs grow on it. The deep growing roots will destroy the earth walls.
The reason flooding is a problem to this day is because of that.
Our ancestors build great things works to stop the floods but they were neglected, fell apart, and washed away.
Here endeth the lesson.
And yes, the ditches beside the house I grew up in were so deep it was like a swimming pool to a toddler.
Drainage is just as important as blockage.
>>985019
Marvelous things can be done to prevent flooding.
There actually are people that are so used to THIS SHIT in the picture, it's like a way of life.
>>985022
i live in missouri on the mighty MO i know flooding, i remember the 93 floods vividly. even though i was only 10.
You build it very carefully.
>>985094
This is just an optical illusion, that fence is most probably higher than the water line. No way that old wooden fence is keeping all that water out.
>>985100
gotta use that water sealer bro
>>984808
It will need a very deep foundation. I'm talking all the way to the solid bedrock. In some places that can't happen unless you go like 50+ feet and that is only for stuff like cathedrals and such.
Long ass pilings are your best bet.
>>984834
hey guys this is DSP and let's play floodplains
>>985532
>DSP
Hi digital signal processor!
How goes the signal processing?
>>985531
whats going on in that pic?
>>985539
If I were to hazard a guess...I'd say severe soil erosion...
>>985531
Bro, you don't need to go to bedrock. Especially for a house. Go below the natural water table and you'll be fine, the soil bearing the load under that won't have any different properties in a flood situation.
>>984808
If you are concerned about soil settlement you need to consider the soil itself.
You mentioned "the south". Most of the soil in the south of the US is basically baby shit when its saturated, so first thing you need to do is move somewhere else.
As another poster mentioned. You may want to consider your ethical obligation to your community before you propose displacing any future flood waters.
>>985556
This.
The pic of the houses on a cliff is an example of using deep piles to stabilize an unprotected slope (in this case a shear cliff) and mitigate the effects of slope failure and erosion.
OP, the design of piles is based on your expected load and your allowable amount of settlement.
>>984808
My state already had it's once in 1000 years type flood.
We just have boats, hurricane survival stuff, and fix things when the water leaves, just like when storm surge comes in. Now, Columbia, SC was kind of fucked, but that's what they get for not living by the coast.
>>986344
No, it's not. The water table is different everywhere, and may be 50ft below ground or 4ft below ground. It's easy to find out. Bedrock may be relatively high where you are from, but often it's hundreds of feet down, and there is certainly no correlation between it and the water table.
Source: a degree in civil engineering which required many (too many) classes on geotechnical engineering
>>986345
Already had your 1000 year flood eh? And you say that like it means you won't have a another one in 2 years....
That term means that the likelihood of getting that large of a flood is so small that you can expect it to happen that often. The same probability applies every year, and each year doesn't really have an impact on the likelihood of it happening again.
TL;DR You are exactly as likely to get that flood this year as next year, as last year, as when the flood happened
>>986626
I am just as likely to win the lottery every day of the week.
not winning doesnt increase my chances of winning tomorrow.
>>986626
>trying to explain statistics on 4chan
Good luck anon! I'm anxiously awaiting the dice vs cards analogies, that should be a hoot!
This guy has it right by the way.
>>986656
For all the apparent hard-headedness, there's a certain genius to some of 4chan. But berating it is part of that, so eh.
Anyway, yeah. Gambler's fallacy, statistics, etc.
>>986656
Actually it should impact the probability of it happening one year, provided it happened the year before. probability of it flooding 10 years in a row is much more unlikely than flooding in ten separate instances throughout the 1000 years
>>986895
Assuming that the "1000 year flood" statistic is exactly correct and does not experience various real world complications...
Ten years in a row (starting now) would be (1/1000)^10, or one in 10^30.
The difference in the other situation is that specific years are not required for flooding, not that flooding one years alters the probability of flooding the next year. Any ten years out of a thousand would be more than twenty orders of magnitude more likely happen.
In both situations, the likelihood of it flooding one year is 1/1000 regardless of whether it flooded the year before. There are just a lot more possibilities for having ten out of a thousand than out of ten.
In real life, statements about areas being "thousand year flood plains" and such rely on analysis of past flooding, and are not perfect indicators of the likelihood of future floods. In particular, circumstances change over time. Rivers change course, changes to land use influence the amount and duration of runoff, and climactic shifts influence things like rainfall and snow accumulation. Having a thousand-year flood just two years ago is unlikely. It's more likely that the estimate was wrong, and that you can expect similar floods more often than once per millennium. Maybe not once per decade, but it would be prudent to build with that in mind.
>Lets say you live somewhere in the south.
Why don't people in Florida just live in boat houses?
>>986950
So you're saying it's like playing dice... with cards? Is there such a thing as a semi-independent event? Or is it all just errors in odds calculations? Not completely trolling/shitposting, either. Only semi-trolling/shitposting. And for the record, knowing my luck, if there were a 1/1,000,000 chance of a place being flooded, I wouldn't live there because it WOULD happen in my lifetime.
>>987040
>So you're saying it's like playing dice... with cards?
A "once in x years" chance of something happening, without complicating factors, means that the likelihood of it happening on one year is independent of it happening in any other year, like rolling dice. In cards, the likelihood of a particular outcome depends on how many cards have already been drawn.
>Is there such a thing as a semi-independent event?
Of course. They're common in real life, as opposed to simple statistical models or games of chance. Real life is a complex web of interrelationships, and lots of things somewhat influence lots of other things
In real life, the factors that produced a "thousand year" flood one year may just be a random coincidence that lined up that year, and it's not likely to do so again for a millennium or so. Or there may be a shifting of factors over time such that "thousand year" floods are more likely to happen now than they were in the past.
Figuring that out takes investigation and analysis. Ratings for flood plains are based on such activities. As with any other endeavor, it's possible to make mistakes at various points, which might have led to mistaken ratings.
>>986909
You're an ignorant dumbass. Not like this conversation matters at all, but you're fucking wrong.
>>987068
>A "once in x years" chance of something happening, without complicating factors, means that the likelihood of it happening on one year is independent of it happening in any other year, like rolling dice. In cards, the likelihood of a particular outcome depends on how many cards have already been drawn.
Statistically the chances of an event happening conscutivly or more than once in that period alters the overall chance. because it is chance of an event provided it has already happened it is called conditional probability
>>987068
So you're basically saying that the population mean isn't the sample mean, and when shit gets real that's when the difference actually matters and engineers start to sweat? Thank you for the lesson, anon.
>>984882
>>984883
>>984892
>>985021
2016, still cherrypicking photos
>>989000
it would have worked if he hadn't left a gap for his driveway
WE NEED TO BUILD A WALL
>>986624
>too many classes on geotechnical engineering
I am really fucking.glad they make sure that civil engineers can understand what they are going to put a several hundred thousand ton footing on.
>>989000
>something doesn't work 100% of the time so it's useless.
>>989045
>several hundred thousand ton footing
wew lad
A very large McMansion house footing would be unlikely to exceed 35 tons.
assume two stories + roof
Therefore 100 story skyscraper is 100 stories + roof
35*3 (close enough, kek) = 105 tons
those are US tons (i.e. 2000 lbs, or like 143 stones or some shit)
>>989045
Fair enough, I just hate designing with dirt. The thing that annoys me is there are a lot of calculations you can do for high(er) end design, but for most applications, the soil is variable enough that we just throw a factor of safety of 3 to 10 on it... Do all this work and it doesn't really matter in the end.
>not living in an invincible dome househttps://www.youtube.com/watch?v=jxsSBHTFk3w
>>989274
Agreed
Most flood plain models are best guesses as well. A lot of the modeling software and research is focused on brides. Aashto and fhwa would be your best bet if op want to perform a real designed flood control method. For soil see aashto bridge design manual. They have settlement equation. Fhwa and army have hydraulic equation and software. See hecras. Source: I am a hydraulic and bridge engineer. PS any design with soil will involve a geotechnical laboratory to analyze the sites gradation, moisture density relationship, and many other factors. Op better have big time money to fix big time problems
>>989078
>105 ton footing is what is preventing the empire state building from being blown over
>>984882
Surprised this guy didn't get busted for this. If you live in a flood plain area, there are some very strict rules about building levees and regrading your property. Permits required and
are hard to get.
The idea is that your property floods so that rich people's property doesn't. The water has to go somewhere and that might happen to be your house.
>>986626
Kek, it's a 32 yr moving average of the peak discharge. Learn to civil engineer
>>990627
I'm pretty sure he did it as an emergency measure, rather than a permanent structure. Thrown up in a hurry when it didn't stop raining upstream.
>>991231
>this is my home town
>>984808
>Lets say you live somewhere in the south. Or really, anywhere that could wind up flooding after a Once In 500 Years type flood. Or even an industrial accident, where for some reason your habitat is flooded for a month.
Let's say you be SPECIFIC, otherwise learn to civil engineer.
If in southern US, buy land on a hill. The land won't "sink", it's been there for millions of years. You don't exclude flood, you live and build above them and accept flooding below that.
Study geography of your SPECIFIC area, then adapt.
Example, I have relatively low property but even Joaquin didn't flood it because I dug a few basic drainage ditches by hand over time since I like the exercise. (Before you think that won't work, look at photos of trench warfare.) Have a drainage plan which you can refine by, holy fuck, observing where rain goes. No problem.
Don't live in an area that floods if a levee breaks unless you live on a hill above any possible flood level. Don't live downstream from a dam, and don't live lower than adjacent lakes. Joaquin breached a shitload of those in South Carolina.
>>984808
Only problem is finding a secure way of keeping it in place.
>>986950
You're assuming that everything is completely independent and random
You are a moron
>>991981
Is it any more stupid than assuming you know the correlations and can accurately predict storm events based on a random arbitrary relationship? There is a reason people assume that Poisson assumptions hold true for this sort of thing.
