The 100 Year Flood Is Not What You Think It Is (Maybe)

[@ethanely674]

As a water resource engineer, I frequently have to explain the idea of the 100-year storm to people. I may just start showing this video instead! Nicely done.

[@terrorhuhn9192]

Few days ago in german was (for our conditions) a 100 year flood. About 160 ppl died in it.. was the second 100 year flood within 10 years tho, many people say stuff like "so, that was now 100 years already?" right now.. thats freaking annoying xD

[@ChrisEffpunkt]

@@terrorhuhn9192 so, tbh, wouldnt it therefore be a decades flood?

[@toomanymarys7355]

@@terrorhuhn9192 It's ALSO because the estimations are falsely based on bell curve probabilities. It's a total load of huey.

[@danielhutabarat7596]

I think you did our job as civil engineer in educating the society and inspiring young people. Never stop posting!

[@TimmyBlumberg]

This is precisely the content that I WANT to watch on KZbin, but am never quite able to track down.

[@TheLychie]

im a student in civil engineering and this dude just showed you how much we go through in water resources/hydraulics class

[@TheLychie]

@Alex Tyson sorry, didnt mean to sound arrogant in that comment. my intention was that it's cool yall got to see what we go through in class, that's all. I finished that class and I still dont know much!

[@desijrichert]

@Alex Tyson The proper terminology is "nobody cares Moby". LOL

[@CarthagoMike]

As a Dutchman, this hits pretty hard today, with all the flooding.

[@MrJeffcoley1]

No worries mate - after it's done, you're good for 100 years!

[@almerindaromeira8352]

I also got this recommended. I live in Germany....

[@Twiggy163]

@@MrJeffcoley1 1250 years for rivers. The Dutch learned long ago that 100 years is not enough.

[@rogermcdaniel7303]

Very interesting video. As a CAD technician (Stantec Consulting,) focusing on water and wastewater facilities, I have often included flood plane data in drawings and (wrongly) assumed that it was "the worst flooding that has occurred in this area in the last 100 years". This was a excellent balance between presenting a "simplified" explanation without wandering into a "overly simplistic" one. This was a GREAT introduction to hydraulic engineering that has sparked my interest to looking into it a little further. Thanks much, and post more!

[@timothyahoffman]

Going down the rabbit hole...... FEMA floodplain boundaries are more "easement" than engineering. If someone asks you to draw it and label the elevations make sure your surveyor checks the vertical datum on your plans first.

[@awboat]

Another thing that really needs stressed is that "any given year" starts tomorrow. And another point, the flood plain is part of the river, just not always.

[@buellb0y]

Needs “ to be” stressed.🙄 But yes, the flood plain IS part of the river.

[@erisdiscordia5429]

I love that your sarcastic comment about someone's typo is edited for corrections. lol well done, you're a true credit to the species.

[@tysaquaticzone]

I work for the USGS, was nice to see the recognition, thanks.

[@nezZario]

Not being mean, I've always heard the public sector is where you go when you can't cut it in the private. How true is that?

[@PracticalEngineeringChannel]

Absolutely not true. Some of the sharpest engineers I've ever worked with were from public agencies like USGS, USBR, and USACE.

[@jeffc5974]

The public sector gets more scrutiny than anything in the private sector, because so many in the private sector rely on the information they provide. You're probably mistaking your experience at the DMV, which is a state thing, not a federal one.

[@blackeyez5033]

Public or private, it all boils down to the individual's motivation to do the right thing

[@krishankumarsanodiya7682]

I'm a Water Resources Engineer pursuing my master's. Most of my work is depend on the data collected from USGS. So thanks 👍

[@monham5041]

Another clear and understandable explanation Grady. I love your videos. I've worked in the engineering industry for almost 40 years and it still amazes me how the general public view statistical base data. To most it seems that 1 in 100 year floods means that the chance of a flood happening in these zones is once every 100 years. Statistics are obviously not well understood. Keep making these clear and simple videos. Maybe the public will start to understand their environment better. 🤞

[@apopheniacMCMLXXXIX]

We need more KZbin channels like this!

[@armorsmith43]

Starfish Prime look at Real Engineering, Wendover Productions, 1blue3brown, and The Engineer Guy

[@pqrstzxerty1296]

KZbin would still ban and remove them as its systems would see as it is reading material from a book becomes a copyright violation. Even humming a song KZbin would remove it.

[@mokin-rui717]

I found these absolutely fascinating. The fact that you're a fellow Texan made me a subscriber.

[@CapturePlay]

Just found the channel through Hydraulic Press Channel and I'm loving it, immediately subscribed! Really well put together videos with fantastic pacing and a pleasing balance between the accessibility and depth of the content.

[@VladVladislav790]

floods are dangerous and can attack at any time. We must deal with it

[@IrchaMan]

vat da fak!

[@ozuf923]

I'm a stormwater engineer and I just wanted to say, you're explanation of the basics of how we get our flow's in the systems we design is spot on and very easy to understand. Thank you for making this video! I do want to add though as the need to really understand how much water is in a basin goes up we do have some less vague maths at our disposal. Our softwares do some pretty incredible modeling (taking topology, sqft by sqft changes in perviousness of the ground, soil types, vegitation ect.) and Q=CIA gets refined a lot. Q=CIA gives you a quick conservative value for a flow, further models and equations help take that conservative value and make it something that you're pipes actually will see and these models can take months to years to make. If you're at all curious (and to any other readers) I recommend checking out you're states DOT manuals on stormwater design, the manuals should have step by step examples on how estimate flow and what storm events are used to design pipe systems. Thank you again for making such a great video! Sorry for the ramble on flow estimation lol.

[@257chapstick]

Governor Abbot said Hurricane Harvey would cost Texas 150-180 billion. that's a lot of money. For a fraction of that couldn't you just prevent flooding by piping Texas flood waters to west texas via the oil and gas company right of ways and pay for it from the exploding state revenues coming from Permian Basin and pouring into the Texas Rainy Day Fund. And therefor kill two birds with one stone. You double the habitable size of Texas by Stopping the flooding in east texas and greening up west texas.

[@SquaresToOvals]

That feel when 7 out of 9 of your friends in your standard deviation excel spreadsheet are made up

[@PracticalEngineeringChannel]

Yeah, Duke Flitznippler is totally real...

[@haph2087]

@@PracticalEngineeringChannel Charles. No last name, just Charles. Not convinced Made-Up Friend 5 and Made-Up Friend 6 are different people. Maybe they are clones.

[@soup-flavored-soup6613]

Pfft friends

[@DiscoFang]

The technical term for friends is standard deviations.

[@midnightclubII]

Duke F L I T Z N I P P L E R

[@Nonplused]

This same sort of misunderstanding of statistics happens in finance as well. For example many (most all I think) use a measure called "value at risk" to quantify the uncertainty in their portfolio. So for example after doing a bunch of highly dubious statistical work they may say that their value at risk is $5 million dollars with a 95% confidence interval and a 1-day holding period. So depending on how the confidence interval is defined, that can mean either 5% or 2.5% of the days will have a bigger loss than $5 million dollars. However nobody thinks about all the $4, $3, $2, and $1 million dollar losses that will encompass 50% of the days and can all get strung together if the market is against you. The 1 day holding period is key, if you cannot exit your position in 1 day the total losses from a market event can be well above the stated value at risk. A good rule of thumb is that if you can't get out of a position the total losses possible in a year are about 11 times higher than the stated value at risk, depending on the volatility and liquidity. And then because many financial and commodity markets are log-normal, the stuff inside the 5 or 2.5% can be dramatically larger than the stated value at risk. As the probability of occurrence is going down the impact is going up exponentially. This is how you get a bank failure or market crash. They don't happen very often, but when they do there is not much that can be done. Some very large trading shops have been taken down by events they thought couldn't happen based on statistics.

[@teddyl7006]

That was good. You didn't insult anyone's intelligence or tried to joke through the hard stuff.

[@Azathoth43]

Yup, left that to the comment section lol.

[@beringstraitrailway]

True, except for the part about taking selfies in front of your rain gauge, lol.

[@General12th]

@@bobsagget823 Dude, what the hell?

[@General12th]

@@w.o.jackson8432 If you look at the discussion tab on his channel, you'll see people have been leaving mean comments for _six years._ Either he's still quite young (and he started his channel when he was, like, ten) or he's been an asshole for a long, long time.

[@mikegerig5363]

bobsagget823 .

[@hudsonevans485]

Yo! Travis County whats up! I grew up there, but now I'm in Atlantis (Houston). It's so cool to see local (somewhat) people creating amazing videos like this that are viewed by thousands of people across the world. Btw totally agree with changing the x-amount year flood system to an x-percent chance system, I was a little confused on why they used that terminology in my civil engineering classes last year. Can't wait to see the next video!

[@NickFerry]

loving the new channel direction - keep it up!

[@PracticalEngineeringChannel]

+Nick Ferry Thanks Nick! I want to feel your beard.

[@NickFerry]

Practical Engineering lol - I wish that was the first time I have had that request

[@PracticalEngineeringChannel]

+AvE taken?! It's always been there

[@NickFerry]

***** maybe too many pixeys

[@K-Anator]

+Nick Ferry This chain of comments makes me happier than it should. Also, what's with people wanting to feel beards? I've been stroked a number of times, occasionally without consent.

[@wxckefekt]

"Good enough." - The entire methodology of my hydrogeology class.

[@MrRoboskippy]

In this case the 100 year flood actually was what I thought it was.

[@willievanhetkerkhof286]

Harvey is gone Irma is coming, every month a 100-1000 year risk.

[@howardbaxter2514]

Willie van het Kerkhof To hell with Harvey. May we never see another Harvey like hurricane again.

[@e1123581321345589144]

same here

[@haph2087]

I don't understand why people would expect it to be anything different. When I first heard the term "100 years flood" I thought "The size of flood that would occur on average once per 100 years?". Admittedly I termed it that way in my head, not "the flood size with a 1% chance of occurring each year", though that is a fairly simple mathematical relation, and if asked for the chance per year I would have replied with 1%

[@mennoltvanalten7260]

Yeah, same. Though I guess as a Dutch person I already have a larger than average reason to know this stuff.

[@JohnHudert1]

Great vid! Liked the selfie shot with the rain gauge (I do that too) and the last shot of skipping a stone - always good to feel like I'm back out on the river. Keep up the good work!

[@opnorty]

Great video. As a fellow civil engineer, I have to explain this all the time. The other confusing issue for lay people is the 1% flood vs the 1% storm and why they dont occur during corresponsing rain events... Keep up the great work.

[@PradeepSingh-br4gd]

I have always been curious about all the stuff we see everyday, your book is the best thing I found this year. Keep up the good work .

[@RowanHawkins]

The National Weather Service in the US also allows you to access the Hydrology Data because they also care about water flows in streams so they can issue flood watches and warnings. If you have a stream that floods often in your area, you are likely to have a flow gague on it someplace. Also Highway departments put data into the system, because many bridges essentially have a ruler built onto a pylon that is visible from shore. Some times those also mark record high water events.

[@amsmarkwilli]

I'm a H.E.R.S. rater, air and water work the same and your vid has helped me understand a little more. Thanx! I'm looking into changing into a different field due to boredom! Keep up the good work with yours.

[@johnconklin9039]

Don't know how many times that I've tried to explain 100 year storms to people, I never do as well as you. Maybe someday explain retention basins and metered outfall. Don't know if that's in the code in Texas, but here in Ohio they've been a big part of the building code for about the last 20 years.

[@waterman308]

been doing basins here in NJ since the 50's or so. we'e elevated it to a level of requiring some kind of Mage to figure out how to make them do all the regulatory requirements - water quality, erosion control, infiltration, flood control. Yikes!

[@matthewlehman7937]

Hi, I'm a civil engineer specializing in water resources, I've never heard of "metered outfall," what does that mean?

[@carmichaelmoritz8662]

i am so stupidd that i dont really understand most of what he said . certain things just make sense while the other stuff is just extra words added to make it sound professional .

[@michaelagius6814]

I work in the Engineering Department in Bridgeport Connecticut City Hall. I get people in my office all the time complaining about being in a flood zone and saying "I've lived there 30 years and I've never been flooded!" Now I'll just show them this video to save myself some time of explaining. Thanks!

[@danhammond9066]

I have been there and done that. After living thru a 100 year flood, seeing my entire city go under water. I know exactly what it is. Further I know what it is to deal with the aftermath, the cleanup, the destruction to families heirlooms. The pain and the healing.By far the clean up and getting back to life is the hardest part of a 100 year flood.

[@dreambydesign808]

Hey, thank you for explaining this. I do work as a junior architect and consistently find myself throwing basic property information like this on my general sheets. I didn't fully understand the difference between the flood plains (you would think we'd touch on it at uni at some point). Either way, I respect the work our Civil and Geotech consultants do--this was a great example of how their expertise is necessary--and allows me to do my work.

[@TheJaredtheJaredlong]

Mies van der Rohe built the Farmsworth House to sit right on the edge of the 100 year flood plain. Then for good measure, he raised the entire house 5 feet of the ground. Since it's completion,, it has been hit by two 500 year floods causing massive damage to the house.

[@timothyahoffman]

farnsworthproject.org

[@fuurinkazan164]

Grady, I just discovered you a couple of years ago and now going back to watch your old videos. Your production value has increased a lot (not saying this to downplay your older videos but you're definitely getting better at your craft!).

[@peterbaston4370]

A great example of dynamic teaching using web technology will replace standard engineering courses. Comprehension is everything : )

[@sbdragoo4463]

As a former civil engineer working with hydrology for bridge design, this is a fantastic video. Great explanation of the topic and the pieces that make this up. Keep up the great work. Your videos are informative and very entertaining!

[@CalvinoBear]

I KNEW IT! In one of your other videos I saw a highway underpass that looked very familiar... From Austin, you are!

[@reluctantlydancing]

This is so interesting. I grew up in Central Texas. In 1998, we had a 100 year flood, then in 2002, a 400 year flood. It was very confusing for me as a kid.

[@matachamoco]

The 100 year flood reminds me of a principle we use in electronics engineering called "mean time between failures". I've seen it mostly used to describe for measuring the failure rate for latching an asynchronous digital signal, where failure is when the latch goes metastable (i.e. oscillates between 0 and 1 by itself). The units are in time, but it really reflects a probability that it would fail, e.g. we want the mean time to be in days or years, but all that really means is we wan the probability of failure to be in the parts per billion/trillion.

[@musaran2]

MTBF is also common on hard disks. And it can be quite misleading, because it turns out HD typically fail young or live old, so combining those lifespan does not make that much sense.

[@LucarioBoricua]

When politicians and concerned voters see the bill of the flood protection projects needed, or how many people/businesses/industries/facilities must be evicted out of the floodway, and how much land would be needed elsewhere to relocate all the affected activities, they'll shriek in pain and agony and sweep the problem under the rug. That is, until the problem starts costing dozens to hundreds of billions of dollars per year, every year. As it's happening with climate change inducing more extreme weather and sea level rise giving more inland reach to coastal storms. For instance, the US Army Corps of Engineers is evaluating the feasibility of constructing flood defenses for Galveston bay and the Houston Shipping Chanel. Price tag? $90 billion. Cost of Hurricane Harvey (2017)? $125 billion. When did the next nasty storm happen? Tropical storm Imelda, 2 years later.

[@MonkeyJedi99]

I first encountered MTBF in the military, where weapons and vehicles, as well as other major equipment, was listed with MTBF (or MRBF - Mean Rounds Before Failure) to give the unit quartermaster working estimates of how much to order, and when.

[@Ratlins9]

Thank you, your explanation gave me a much better understanding of flood plains and the 100 year flood. This will help me determine where I relocate. Your videos are the best!

[@zachydrogeo]

Grady: "we can't make everyone buy flood insurance" South Amboy NJ: hold my Bud Lite

[@tylerjones2407]

Thank you so much for making this video! I have heard people talk about the 100 year flood, and completely misunderstood it. Your explanation was very clear and interesting!

[@chasemixon6327]

that just made my brain hurt... but good stuff.

[@thekittulegend]

Chase Mixon he feeds information too quickly and often does not explain much about a concept and rushes to the next one.

[@misterdinner3648]

new2k16rapper Pretty much how lectures work in higher education.

[@Huyvovo903]

The information he presented was very bare-bone. Explaining every single concept in this video would take hours assuming the viewers have the basic knowledge of fluid mechanics. And no this is not how lectures woke in higher ed, it's meant for an audience with little to no knowledge regarding the subject. He barely went over any math except for some basic statistics and rudimentary formulas.

[@gigglesgames1]

Basically all you need to know is that take the phrase "x year flood". Take that x and put it in the fraction 1/x and then convert that fraxtion to a percentage. So a 100 year flood would be 1/100 which equals 1%. The larger the x the least likely it will flood in that area

[@mrdecider]

Thanks!

[@TheBookDoctor]

I think you forgot the link to the FEMA flood plain maps. Great video, though. Very interesting!

[@PracticalEngineeringChannel]

+TheBookDoctor Fixed! Good catch.

[@guyh.4553]

I've worked in natural resources and ag conservation for 20 years, land use planning for 5 years. I really enjoyed and learned information, specifically the probability of high water calculations with EXCEL, and it was very useful. One suggestion is how to determine Bank Full and 2 times bank full determination. Another, using engineering/land survey tools, is to show how to determine channel depth. I look forward to more videos!

[@geoffreyreeks2422]

This presentation is well done. It would be very helpful for engineers to understand the changes to hydraulic head by flows into and through storm water pits. I think that a lot of unexpected flooding occurs because we have built storm water pits that aggravate hydraulic head. If you do a report on this topic them please tell me. I am easy to find. Thanks.

[@bloqk16]

I recall the town I lived in had a "100 year flood," where the town council the following year wanted to take steps to improve the street drainage in the community. Many citizens in the audience were against it, as taxes would need to be raised to do the drainage projects. I recall one vocal person in the audience saying that we wouldn't have to be concerned about a similar flood for another 90+plus years, where he concluded that plans could be delayed and let a later generations deal with it. Ah! But, two years later the town was hit with another massive *100 year flood!* After those experiences, I've never put any serious stock into the phrase of _100 year flood,_ as, where I lived, it happened twice in _four-years!_

[@CUBETechie]

It's nice that it comes today in my recommendation. Is it because of the events in Germany?

[@almerindaromeira8352]

I also got it (again) in the recommendations. Grüße aus Hamburg

[@terrorhuhn9192]

probably that's the reason.. algorithms hits u xD

[@DaHitch]

The algorithm works in both mysterious and predictable ways.

[@jonanderson70]

Hey Grady, I just found your channel last night and Im getting obsessed with watching your videos. I just started my 3rd semester as an engineering student here in Virginia. I've only been here for about 2 years, but I was born and raised it Manchaca so it was cool to find out that you're a fellow Austinite. Thank you very much for your videos!

[@KingdomOfDimensions]

The number of dislikes on your video really doesn't matter, and as long as your video isn't factually incorrect, uninteresting to the point of tedium, or a controversial opinion, you're unlikely to have more than a few percent dislikes. Inviting the audience to honestly represent their feelings about a video using the like/dislike buttons or by leaving a comment is more endearing than directing them to hit "like" regardless, and won't negatively affect the outcome.

[@abhigyanchakraborty5563]

I have recently started working as a hydrological modeller at Department of Space, Govt. Of India. And I loved every bit of this video.

[@supernova4562]

Missed a chance for a pun at 7:04: "[water] shapes every facet of our lives" and faucet of our lives!

[@jameswyatt1304]

Thank you for a good link to share with friends. Your videos are an interesting and efficient use of time, though I'm glad I can replay parts of it a few times when it's deep, so to speak. Approachable engineering and science material is a wonderful thing to share.

[@tzisorey]

And with recent happenings in Texas, this video has made it's way in to the Recommended Videos again.

[@martendschrage]

This explains a lot. for someone who's been through many floods, I didn't understand the "year" concept. But you didn't mention snow fall and frost rate. things we need to worry about up north.

[@ef2b]

Physicist here: Measuring something to 1% is no walk in the park. This is even more true when you're talking about understanding the shape of a distribution out in the 1% tails. Even if you have a theoretical basis for the shape of the distribution, the 1% tails are generally mucked up by instrumentation effects, noise, background, etc., etc. So, if you think the technical parts of this seemed hard, I suspect it is even harder than it appears while, simultaneously, requiring a substantial amount of prayer and a fair bit preparing to run to high ground anyway. Nice video!

[@ninjapancakes9435]

This is one of if not the first video that decently explains storm water concepts! Thank you so much! You should make a video on what a Storm water pollution prevention plan (SWPPP) is! ;) (Thats what I needed to learn, usually I look to KZbin to learn about stuff I have no idea on, but there was almost nothing on the subject which was kinda disappointing because it is something that is important to consider. Ive been subed for awhile so this was a pleasant surprise! Thanks for all of your hard work.

[@jelmerth]

Can the past floods in Germany, Belgium, Austria be in this line? Nobody expected this.

[@patrickspendrin3107]

Obviously. The problem with floodings is: the higher the flood level is, the less likely it is to occur. if you look at a 1000 year period, then you'd see that certain flood levels are reached 10 times in that period - that is the 100year flood level. From a single event, you can't tell that easily though. There are problems with this statistical analysis though because various boundary conditions have changed over time (climate, think of the small ice age in central europe), building density (especially in such highly populated areas like the rhine-valley), river straightenings... And what you have to remember: a 100 year flood occurs around once in a life time. There is a high chance that there is nobody alive to tell you about it. For comparison the flood level markings at Schloss Pillnitz: upload.wikimedia.org/wikipedia/commons/6/6a/Hochwasserstand_Pillnitz_Schloss.jpg You can clearly see that the last flood before 2002 was 150 years ago. There simply was nobody alive anymore to speak about it. I think the same happened for the floods in rhine region this year.

[@TheSmiley316]

It's only for Americans, they don't think there is anyone else other then them

[@buckshot70737]

Thank you so much for the video. I have experienced catastrophic flooding many times in my life. This video gives a great perspective of how many variables come into play in circumstances that cause flooding. Thank you.

[@cirurginn]

5:00 hey pervert why are you recording me? I was recording the stream gages I swear! tell that to the police

[@mrnice88x]

haha she looked over too

[@greenwolfx]

Thanks for the video Grady. We all appreciate the effort you put into them 👍

[@thetheflyinghawaiian]

Woo woo, Hydrology major represent.

[@thetraveljack]

AdamOrnelles usually you need a masters for hydrology

[@xavierhenriques1116]

I adore this channel You are one of the reasons I have decided to go back to school and finish my engineering degree Thank you, Sir 🙏

[@davidjohnson4669]

Well you got my sub easy information to digest on a curiosity click :3

[@chriss3948]

I couldn't have agreed more. Guy seems to have his shit in one basket, I enjoyed it really.

[@BRollOffroad]

this is my third vid, glad i found this.

[@angelkitty11]

:3

[@sharedknowledge6640]

Awesome video and especially applicable with Houston, hurricane Irma, etc. You do a really good job of presenting concise explanations striking a good balance between the technical side and using layman' terms.

[@briansmobile1]

Fish jumps in foreground → 0:43

[@dcgo44r]

Good eye! Fisherman? Lol.

[@jo-gu4ln]

thank uou

[@creeper8647]

You want to know what I think? I think this may be the best channel on YT. And that's high praise from a seventy-five year old lady.

[@FlatBlack_240SX]

@5:02 I ride my bike by that gauge every day on my way to work!

[@hfyaer]

You've improved your editing a lot. And I like your humor. Even if it's weird, it's genuine. It is part of the world of top level engineers that you're exposing.

[@andrewfrey6960]

The fact that this video appeared on my feed right after Hurricane Harvey.

[@EdmondWanyela]

Thanks for making this explanation of " return period " easier for everyone.

[@John_Ridley]

Mmm, that is actually exactly what I thought the 100 year flood was. The only people confused were the people who think that they can be "due" when gambling or something.

[@PracticalEngineeringChannel]

More people would probably think they were "due" for it if they called it a 26-roll dice throw. It's a terminology issue.

[@SentientTent]

26 roll?

[@ericv00]

They should call it "the 100-sided die roll". In this case, a critical fail being a flood. ...And a critical success being that you become a hydromancer.

[@thorr18BEM]

It seems a lot less crazy to believe there might be cyclical behaviors in nature than in the behavior of dice. This is especially true since we *know* the days, months, years, and seasons are cyclical as are less well known phenomena like earth's axis precession, the sun's 11-year cycle, a possible 105-year cycle seen in carbon-14 studies, and more. It's not just astrologists or gambling junkies who might think a "100-year flood" probably refers to something cyclical, even if it doesn't.

[@TheCptCoy]

Yeah dumbasses be dumb as usual.

[@shabadooshabadoo4918]

Rofl that 2 second clip of you taking a selfie was a brilliant treasure of comedy that I hope everyone payed attention to.

[@bernardo00124719]

5:04 nice.

[@KarlBunker]

Yeah; gotta love that stream gauge. 😉

[@noahway13]

7:39

[@weaslemin7728]

Bruh.

[@liu408]

haha I was gonna say that too #buns

[@Superlokkus5]

I knew that comment would be here

[@Phelixc]

This reminds me of when I was working on an oil rig. The rigs are built high enough that the lowest deck (cellar deck) is only hit by a 30 year wave... I was on board one of those rigs, when one of those waves hit cellar deck (and I was also on cellar deck inspecting pipes with a snake cam when it happened). Shortly after the wave, a smug rig captain gets on the PA to announce "ladies and gentlemen, that was the 30 year wave, it will now be 30 years till the next one hits us" which was shortly thereafter followed by a second wave hitting cellar deck... All my equipment was ruined and I was soaked from head to toe... Quite the experience...

[@AUSTINBGRANT]

What's the probability of a 100 year storm occurring in a 100 years if it's normally distributed? The answer is not obvious.

[@PracticalEngineeringChannel]

The probability of having exactly one 100 year storm in 100 years is 37%. The probability of having at least one 100 year storm in 100 years is 63%. This is application of binomial statistics if you want to learn more.

[@AUSTINBGRANT]

That is correct, thank you! I love your channel and have watched all the videos today and study civil engineering myself.

[@Kevin-ci1uo]

IIRC an event with probability 1/p happening exactly once in P trials is always ~63% which I think is a pretty fun fact.

[@Angel33Demon666]

+Kevin Markielowski Isn't this the geometric distribution?

[@Kevin-ci1uo]

Angel33Demon666​ man its been a while since college! A geometric distribution is basically, "how many until" whereas a binomial is "how many in x" they are very closely related. In my example above its probably of 1 "successes" in p years, so you can use binomial, I think you can also use geometric because some factors will cancel out.

[@dustinhughes7643]

I’m a Realtor in Metro Detroit. I really appreciate how you explained this. Next time a client ask me about the 100 year flood. I’ll share this video.

[@exceisior3145]

>engineering >users imperial measurements

[@cr7rulz97]

hey, Grady, I'm from Kerala, India, and we were having the worst floods in our state over the past few weeks, since 1924, and given that its been almost a century, i suspect we are indeed recovering from a 100-year flood. the video was extremely informative and has helped me to gain some valuable insights, keep up the good work!

[@VonGeggry]

ha, Civils, with your using imperial units, and you're huge estimations, and your concrete canoes.

[@ShaneDGri]

Geoffrey Vonbargen and providing clean safe potable water to your house that conveniently comes out of a tap that you can turn on and off at will. Then to 'tap' it off (sorry couldn't resist) we'll also provide you with a convenient way to remove your wastewater and treat it for you. Thank you Civ Eng.

[@JustCheckingMusic]

Imperical units is not something typical to this field of research. More like geographical *uche* the USA *uche*

[@MrHamsto24]

Coefficients are the reason I don't trust anything built on a "model." Love your channel. Always a logical, understandable delivery of observable information.

[@tsd560ti6]

A good model hits the SweetSpot between Guessing (inaccurate, especially for unexperienced engineers) and Experiments (expensive for every case). If possible, I would design by the model and test it with an experiment, thats true :D

[@keenanpepper]

Oh, so the 100-year flood actually IS what I thought it was.

[@chinoYochino]

Thanks for the nice video. I just studied NRCS TR-55 at my hydrogy class and this video really helped me understand a lot!

[@bwhog]

One of the things I like to point out to people is that no matter how careful you have been, no matter how well prepared you think you are, Mother Nature is always ready to one-up you and proves this constantly. So it is with flooding. The flood risk now is really that there is so much more development uncomfortably close to rivers and washes that when one of these "100 year floods" comes through, it does far more damage than it did in the past, not because it was any worse (100,000 cfs is 100,000 cfs) but that there was so much more in its path that it could destroy, so the aftermath *looks* so much worse even though it didn't crest any higher than it did the last time.

[@stanmccorkle]

I'm grateful for your willingness to share your knowledge with the world. Good work explaining the term 100 years flood. Speaking of floods. How much do you want to bet that Brenham, Texas gets an incredible 20.50 inches of rain on May 27, 2016, making it the wettest day on record, since 1897?

[@jerodstanley3752]

Hydraulic engineer here. The flow calculation method you mentioned is the Rational Method. It is only used for drainage areas 200 acres and smaller. We use other methods for drainage areas larger than that, including methods that take more factors into consideration.

[@texw4062]

5:00 I really appreciate the beauty of this stream guage.

[@styrex4261]

it is amazing how smart yet unaware we are about the world around us

[@StrawberryblondeHobbit]

Thank you this was informative and you broke it down just right. I am trying to learn one new thing a week or so. Keep up the good work.

[@SnappyDragon2]

I'm a system safety manager dealing with complex multidisciplinary projects, this sort of straightforward explanation of engineering concepts/terminology is really effective and useful.

[@emeraldphoenix7499]

Thanks for putting this together. I had a general sense of what the term meant, but I hadn't seen the specifics. I can see know why one of our local retired hydrologists was a bit squeamish about folks demanding exact answers. The good part is, even with the minor fudging going on, we've gone through a pretty bad flooding period locally that lasted almost a month and the forecasts were extremely helpful. From an emergency management standpoint, it worked this time. I can also see why this is tough to explain to EM folks. Most don't have science or engineering backgrounds (often public safety instead).

[@woodenkat8971]

I love engineers. All thar practical information and a way to inform the rest of us. This is awesome. Thanks! Going to use it with my kids, homeschooling is so much easier with youtube.

[@jeffebert9463]

Great job of shedding light on a very complex subject in a brief video.

[@christopping5876]

As a hydrologist, that is a beautifully put together video. Essential watching for all engineers and Earth scientists in this field. Thank you.

[@ShahrukhKhan-jy4ly]

I really appreciate that you share quality engineering videos for young aspirants to learn and design future communities.

[@diannelinam2407]

Very interesting video! I live in a flood plain area and did my own work determining our risk on a new home. I had the advantage of having the TVA as a great resource. Thanks for this excellent video!

[@dsh696]

Excellent video! Very easy to understand. Other possible topics: How do hurricanes develop, how to manage floods/flood protection (e.g. rain barrels, permeable pavement, etc.)

[@LD-qj2te]

This is what makes the internet, shared learning and collaboration and cooperation awesome! Thank you for adding to the body of knowledge ! This is a great point you should expand on ideas such as black swan or six sigma events!

[@JamieJobb]

We appreciate your caption (use of the word "maybe") --- because, of course, you only know what YOU think, not us! And that's practical engineering!

[@Iamconnorlee]

these videos have so much content and you actually learn something. and can take notes if you want to actually remember

[@ralphbyers6136]

Love all of your videos, Grady!

[@nickpetersen5934]

Yo, not even done with the video and I subbed. Great stuff. Really gets me psyched to become an engineer.

[@mrdecider]

Very good, insightful even to me who has worked with this stuff as a PE for 40 yrs, I learned a lot. Standard Deviation, and Inverse of Probability, ie 36th dice roll- excellent. I began as Engineer in mountainous Monterey Co CA, "who cares about an Hydraulic Grade Line"? Moved to FL, with 1 ft drop in 2 miles!! Now needed HGL and Time of Concentration.