> temp > à-trier > what-is-a-weir-practical-engineering

What is a Weir?

Practical Engineering - 2019-02-25

A weir is a small dam built across a river to control the upstream water level. Weirs have been used for ages to control the flow of water in streams, rivers, and other water bodies. Unlike large dams which create reservoirs, the goal of building a weir across a river isn’t to create storage, but only to gain some control over the water level. Over time, the term weir has taken on a more general definition in engineering to apply to any hydraulic control structure that allows water to flow over its top, often called its crest. In fact, the spillways of many large dams use weirs as control structures. So how do they work?

-Patreon: http://patreon.com/PracticalEngineering
-Website: http://practical.engineering

Writing/Editing/Production: Grady Hillhouse

Tonic and Energy by Elexive is licensed under a Creative Commons Attribution License
Source: https://www.youtube.com/watch?v=U6fBPdu8w9U

This video is sponsored by Skillshare.

Real Engineering - 2019-02-25

Found this really interesting. The weir in Galway, my hometown, creates a pretty unique cityscape. I have always been fascinated by it, but never really put much thought into it why it existed.

Cian Mac - 2019-02-28

Hey I'm from galway too, used to row just above the weir.

Shin Gojira - 2019-04-08

Cn you do a collaboration

AMULET72 - 2020-02-29

That salmon weir (along with others) on the Corrib in Galway is the reason a lot of south Mayo and north Galway is experiencing serious flooding at the moment.

Arya Manake - 2020-03-13

Real engineering has joined the chat.
😂😂😂

Jack Kenny - 2020-09-18

I thought it existed to make waves for kayakers :)

John Guastavino - 2019-12-02

Me the next time I see a weir:
"It's actually called a weir."

ゆ〜のちゃんねる。JUNO - 2020-08-30

lol i always thought it was a vaier

Gta 5 Lovers - 2020-09-05

Same here

Brian Wallace - 2020-09-06

How weird 😅

Lowell Arnett - 2020-09-17

I thought the same the first time I saw this video, but now I know, I'll never remember that term.

Hunter Green - 2020-10-08

Weired flex but okay.

Seabastard - 2020-02-28

Youtube: Ever wondered about Weirs
Me: Nope "click"


And yet i watched it all, great vid.

Bruno Darini - 2020-05-22

That's the algorithm knowing more about us than yourselves

Michael Hyre - 2020-06-03

LMAO me as well.

State of art - 2020-07-08

He lost me at ‘mitigate’ yet I watched it.

JayBird - 2020-09-16

Same!

John Smith - 2020-09-16

Weirwulfs?!

khtam - 2020-06-30

youtube randomly recommends this video and I find it interesting.

Davin McCoy - 2020-09-16

It wasn’t random.

John Smith - 2020-09-16

Ditto I love this guy’s videos

Devaraj L - 2020-09-21

Do watch, /the social dilemma_

Nirvaan Aggarwal - 2020-09-29

I relate with this comment

DragonMaster485 - 2020-10-05

That's how everyone finds this channel, no one searched for it they all found it through recommended.

Sean Walter - 2020-03-26

During the video you say, "Flatten the curve." I can't help but think that's why you just now showed up when I've been watching corona virus videos. The algorithm listens!

Bo pete - 2020-05-06

@Paul Freedman That's called confirmation bias. You see random things all the time, and only notice when they are oddly relevant.

Reason - 2020-06-01

You really think delivering videos that people will click on takes this much work? How about the fact that you clicked on his previous videos?

Last Prophet - 2020-07-15

Skynet omg!!!

jimmy rustler - 2020-08-04

Meanwhile:
Day 140 of the 14 day lockdown

David Weikle - 2020-08-11

jimmy rustler but muh flat curves

Kyle Mouttet - 2020-03-06

If a pier is an artificial outcropping over water for people, then it makes sense that a weir is an artificial outcropping over water for water!

Magnus Juul - 2020-07-29

how wierd ...

Gord Baker - 2020-08-20

A Pier is a man made structure IN the water to provide calm waters on the leeward side.

swapode - 2020-08-24

@Gord Baker I think you might be confusing pier with mole. At least since we're speaking english. In other languages like german you'd actually be at least partly correct. Weird.

Gord Baker - 2020-08-24

@swapode nope. Moles burrow in the ground eating roots and worms.

Psilocybe Vibe - 2020-09-05

Mother of God.....

v n - 2020-03-31

3:10 "So how we can flatten this curve?"
Flattening curves before it was cool.

Daniel Daniel - 2020-07-16

ikr, everyone a copycat

VedVids - 2020-03-17

YouTube algorithm heard 'flatten the curve ' thought this is relevant in present times and recommended it ,,,,
Very subtle

Reason - 2020-06-01

You really think delivering videos that people will click on takes this much work? How about the fact that you clicked on his previous videos?

VedVids - 2020-06-01

@Reason the comment literally meant it's not much work , and I just explained how I came across this video .

Reason - 2020-06-01

@VedVids Yeah okay, if you think transcribing every video to look for current phrases is an easier explanation than the fact that you've clicked on this or similar channel before.

VedVids - 2020-06-01

@Reason Im defeated . Pls enjoy the day!

Reason - 2020-06-01

@VedVids lol people sure love to find patterns in noise

Supergaming101 - 2019-12-22

YouTube: hey you goin' to sleep?
Me: yes, now shut up
YouTube: What is Weirs
Me: *wakes up*

Overwhelming Euphoria - 2020-03-06

The piano key Weir looks like a work of art.

Ross Marinov - 2020-06-28

Engineering is a sort of art and practical use. So it is actually win - win :)

MultiPleaser - 2020-07-19

In engineering if a component does one job, it's good. If it serves two functions (like a normal weir), it's great. If it serves three functions, it's genius (like an artsy weir).

wensou - 2020-09-13

I clicked the video just because of that thumbnail image. So I guess his skill-share course on how to get more clicks works.

Andrew Weir - 2019-12-02

Practical Engineering: What is a Weir?
Me: Me

ArgentOrangeOK - 2020-03-23

Related to Tom Weir?

Buhklao - 2020-04-20

Yo same

travy w - 2020-04-28

lmao right

Andrew Weir - 2020-04-28

travis weir ahh a fellow man of culture

Matthew Weir - 2020-08-24

Hello fellow Weir, Co-worker sent me a link to this video today. Today he learned something I have known about most of my life.

Mike Oxlong - 2020-07-15

4 million people: engineering is my passion

Siddharth - 2020-09-20

4.5

Siddharth - 2020-09-20

I don't give a fuck about engineering video is just interesting

Hus Sae - 2020-02-29

Me: Lets check Youtube for corona plague updates
Youtube: Would you like to know What a Weir is instead?
Me: Okie, looks interesting

Shaun Torpey - 2020-03-04

2nd that.

Valerie Pallaoro - 2020-03-08

Perfect assessment ...

Sean Walter - 2020-03-26

I'm convinced the algorithm heard him say "flatten the curve" and suggested it. I'm here for corona videos too but still watched the whole thing

S FERG - 2020-04-18

Me: let's watch YouTube to get away from Corona Virus updates

phalcon23 - 2020-04-28

Some are choosing to numb their minds by watching tiger king... others are using this time by expanding their mind watching channels like this.., or this old Tony, or niels (I thing thatw his name, the young guy who does chemistry) honestly, I've learned more in the last month than in a long time.

A wild Filing cabinet - 2020-05-07

Youtube: hey you know what a weir is?
Me: don’t know, don’t care
Youtube: what if practical engineering teaches you?
Me: ... aight

mnaufal ihza - 2020-05-13

Mom : Son look a mini water fall
Son : Actually, its called Wier

Q. E. D. - 2020-09-19

PE: What is a weir?

Me: 80% weird?

Seriously, an interesting and informative item. Thanks.

stewart choo - 2019-11-30

me: watching this video just to feel smart
also me: really not understanding anything

Sophia Cooks - 2019-12-05

I will try to put it in layman terms. If you lived on a lake with a river coming in and a river going out. And you wanted to lower the level of that lake no matter the flow rate of the river. You can build a Piano Weir or Wedge Weir on the River going OUT of the lake. It will increase the mouth of the river allowing for more water to flow through thus lowering the level of the lake forever. Okay not forever... as long as the weir did not wear out. LOL.

b8e71fcbe2e195c67d8d16734013d20f - 2020-02-23

How does watching a video make you feel smart? The video is telling you information, not the other way around. That you don’t understand the information should make you feel dumb.

stayOnTheBike - 2020-03-26

Same

Jumpercable wireless - 2020-03-04

He's a guitarist and founding member of Grateful Dead.

ShamanSTK - 2020-04-23

Weir everywhere

conservat1vepatr1ot DL - 2020-04-26

Jumpercable wireless

lol...

I know his daughter. She’s sweet and pretty darn attractive.

Tranny Niggot Fagger Whore - 2020-05-14

Read this as Guitarist Found Dead

My Lord - 2019-12-07

The photo of the Hoover Dam at 4:09 shows a high water level overflowing into the spillway. It must have been taken more than 20 years ago. The water level is so low now that there is about 100 to 150 feet of the intake towers are exposed.

ArtumTsumia - 2019-12-08

Now you've got me wondering what the flow into the dam is like. I visited recently and the water is significantly lower than the towers or overflow weirs, but there's other places that the water flows out during 'normal' usage, so there would probably need to be significant watershed upstream or perhaps oncoming drought where they want to store that much.

MrCloudseeker - 2020-04-25

I was there for the last time this happened in the last week of May or first week of June 1999. It was amazing sight and the sound of the water flowing over the gates into the spillway was amazing. The operators were very worried about opening the gates because they had not been tested under stress in decades or ever.......There are bypass flow tubes, but for some reason most of those had been capped off for reasons to which I do not know. This picture is older from the looks of the cars.....maybe sometime in the 80's.

rupe53 - 2020-05-03

@MrCloudseeker ... the bypass tubes were used during the original construction so they had a dry area to build the dam. The original tubes have not been used since then. Most likely there are more tubes within the dam itself but I have never seen any reference to them. Perhaps they are there to flush silt from the bottom? Who knows?

Derek aka Derek - 2020-07-16

there's old picture of low water levels too... relax. you know the water doesn't all cross the dam, much of it is sent to las vegas.

John Smith - 2020-08-07

That's a nice picture. Imagine how the designers/engineers were sweating it when that thing first filled with water.

TitanFighter - 2020-09-29

YouTube: “You want to hear about weirs?”


Me: alright you got my attention,

Overwhelming Euphoria - 2020-03-06

The fact that YouTube can predict what videos I want to watch without me having any prior interest or knowledge of the subject is slightly creepy. Awesome video though.

wideopenoutdoors - 2020-03-14

ai is a hellava drug

Kyntteri - 2019-03-04

Dam if you do, dam if you don't. It's weir, I know.

keir farnum - 2020-03-06

Kris Kringus
Whooooosh. Over your head.

Jeff Warner - 2020-03-09

@keir farnum maybe it was not weired enough for him

Jeff Warner - 2020-03-09

Wouldn't have been, if it was weired enough. 😏

pappi - 2020-03-09

As a German speaker it hurts to hear the pronunciation

David Butler - 2020-04-25

Watevever you say

Nicholas Rusanoff - 2020-07-10

DO THE MATH EQUATION WITH EXAMPLES.
‘Merica CANNOT “fear” MATH!

Robert Nelson - 2020-05-03

3:10 “How do we flatten this curve?” That was a different phrase one year ago.

Trout Hammer - 2020-05-01

I'm going to try some of these shapes in my aquarium sumps to improve aeration

Griffin g - 2020-04-27

i have heard the term “low-head dam” and my city is trying to get them removed because they are dangerous

blipco5 - 2019-02-25

I'm one who loves viewing dams and structures built to control waterways for our benefit. If I see a sign along the road that says "dam", I immediately turn off and investigate. This information will help me further bore my friends. Thank you for that.

jo - 2019-03-08

Electron i like to follow them to see how many times it branches off and where it starts/ends and to see how it’s shifted over the years.😊

QhTl9 - 2019-03-10

Damn

Game Seeker - 2020-02-29

Ps1 hagrid

w a t e r

Mileyard Gigahertz - 2020-05-11

Dam that's a weir hobby

blipco5 - 2020-05-11

Mileyard Gigahertz ...😂 I see what you did there. 👍

Chrisroygbiv - 2020-04-22

"So how can we flatten this curve?"
Rona: Allow me to introduce myself...

FDroid01 - 2020-04-21

Ah yes, controlled weirs or as I like to say Weir: Automata

Tom - 2020-04-26

Always wondered what they are. They have them on a much smaller scale in waste water treatment plants. I'd be interested to know how it applies specifically in that scenario

Jared Pope - 2020-07-23

When I was a kid we had a damn that would occasionally flood for no apparent reason. They couldn't figure out where all the water was coming from. so they just paid some civil engineer to come and solve the problem. the whole thing was weird.

I refuse to be ashamed

I did a thing - 2019-02-25

Well, i'll be "damed".

August XIII - 2020-01-20

SIRENS BELONG HERE. WET

August XIII - 2020-01-20

@GenuineBronxite mitatgate all

August XIII - 2020-01-20

@Sigma more on that later.

James Langford - 2020-01-27

I did a thing i love ur channel and have been subed since 30k

seattlegrrlie - 2020-03-10

😑

worxharder - 2020-05-06

Me: "what did you just call me?"

PsyphBassQuake - 2020-08-07

Everyone: youtube recommendations are broken


YouTube: hold my weir!

pen_BERRIES - 2020-09-20

Whenever I think of weirs, I always think of that one episode of Top Gear where they are driving a homemade hovercraft down a river and they go down over a weir, and then while trying to go back up it, they burn out their engine.

leo ll - 2020-04-26

Instead of using the "weir" equation, I opted for using the "juicedratic" equation.

az zahar - 2019-03-11

In another episode of: Youtube algorithm brought me here

Christine Chesse - 2020-03-06

Weir, right?

Overwhelming Euphoria - 2020-03-06

I swear they're keeping secret some AI that's already surpassed human intelligence and can simulate someones brain.

FS7Snyper - 2020-03-10

I dont even know how I got here

Patrick Hallquist - 2020-04-19

This freakin' channel is my new hobby! I have always been curious about the whys and hows pertaining to the flow of water.

TheMrvidfreak - 2020-04-20

Strange indeed. In fact, we got weir'd.

Richard Tan - 2020-07-02

Me: it’s 4am, i need to sleep
Youtube: WEIR

Paul R. Screvane - 2020-04-26

for once YouTube, you've made me feel like you know me. Like you REALLY know me.

Celanis - 2019-12-04

Some weirs can write books. I really like The Martian which spilled from Andy Weir.

LaGuerre19 - 2020-03-03

"Thank you for watching, and lemme know what you think."
...
You know what I think, sir? This is the best channel I'm subscribed to on YouTube. Thank you for your hard work, and for making engineering so interesting. All the best.

Ahmad A. - 2020-04-24

“We can’t hang out with you you’re too weir”

KeiNovak - 2020-05-22

2:48 - No way! I know this area. Do you live around here or was this from a random video you found?

Sophus VD - 2020-07-12

"So how do we flatten this curve?"
^ Prophetic words in 2020

Rick Sanchez - 2020-08-23

I read it as:
"What is a Weiner?"

Ross Ozarka - 2019-05-24

Weir, ogee, nappe-- so many great scrabble words!

aboctok - 2020-04-26

@SupaBwad Hah, I wish you were right. I'd even feel sympathetic. But this is pretty widespread and evidently growing in popularity. In Australia we have an equally grotesque "impediment": every sentence clause ends in a sharply rising tone, equivalent to a question tone, or the intermediate items in a list. But it's placed on every sent^ence, except the very final sentence in a paragr^aph, which takes a descending cad^ence. Then the whole thing rep_eats.

Once you're awake to it, it's intensely irritating. We think it came from New Zealand in the 80s and 90s. It feels like a meme from the movie Idiocracy.

SupaBwad - 2020-04-26

@aboctok i played games with somebody like that, i didn't realize it was the same thing just from outside the US. It's always nice to hear from different people, i try to just be positive lol.

aboctok - 2020-04-26

@SupaBwad Well, positive is nice. But the phrase tough love has a basis in reason. If you make a typo, then why should it bother me? On the other hand, if I persistently avoid all disciplined thinking just because I'm more comfortable that way, what right do I have to expect others to extend themselves to protect or promote my interests? And that could be as simple as how diligently they serve me a cup of coffee. 😉

SupaBwad - 2020-04-26

@aboctok i mean i do try to fix the grammar still. Lol.

Mountain Cynic - 2020-04-28

Yep, this one served me well!

draksionar - 2020-10-09

In our vicinity lies one such flat weir ( Prague - type) in disrepair. Severely cavitated by water to extent that hole undermining the stucture, where water drops and whirls has depth over 4 meters now (and increasing). Any slate chunk in that hole under 2 metric tons of weight got shreded to gravel. Same fate would face any unlucky swimmer, who would get sucked by it I guess.
PS.: I can send you picture of the said weir, if interested.

Oregon Patriot - 2020-03-06

The first Weir I ever saw turned me into a 'Dead Head' ... and although the Greatful Dead is no longer together... Bob Weir is still rocking!
Casey Jones you better watch your speed!

ElTurbinado - 2020-02-17

I really couldn't wrap my head around a lot of this. I think the rating curve thing could have used some more illustrative explanation.

But I still love your videos. This one made me feel like I missed something though.

Craig Iedema - 2020-08-24

This showed up in my Youtube suggested video feed, nice timing I was having a discussion on water flow over dam spillways last week, as I visited the dam at 2:52 in this video (this "weir" forms a lake of 1859000 Megalitres).