to not understand how the Thames Barrier works

[clam]

Just reading a link on the bbc website here and I don't get how closing the barrier can possibly help the level of floods way back upstream at Teddington.
I daresay they know what they're doing but surely leaving it open would allow more water to flow out to sea, particularly at low tide?

[FoxesRevenge]

Wouldn't it also flow in if it was open?

[Monty27]

I'm always a bit confused too, I think they shut it to stop water coming in.

[ladypete]

No idea here someone come and fill us in

[Custardo]

i think its possibly bullshit and only exists for great filming opportunities a la spooks

[OrangePixie]

They shut it at high tide to stop the waters rising further then open it afterwards. I think.

[jacks365]

It's closed as the tide rises to prevent tidal water going too far upstream and then reopens when the tide turns. It isn't kept closed.

[Jaisalmer]

So glad someone asked this... What are those big shiney, domey looking things then ...

[MaureenMLove]

I'm going to say something that I say on a regular basis in the classroom now....

'Read all the text and you'll be able to answer the question!'

It explains how it works in the paragraph under the diagrams.

[Nittyb]

This puzzled me too the other day so I had to look it up ! Apparently they close it on a high tide to keep it back & make a space for the extra water coming from the river , if they don't close it the high tide would push the river water back & flood parts of London. I really need to get out more .....

[Cranky01]

It's to keep London dry and not flooded. Which seems to be the main aim

[ReallyTired]

The river thames is a tidal river as it is an estury. When the tide comes in from the sea water flows up the river. It means that places like Molesey get hit with water coming up the river as well as coming down. The flow of the river is also controlled with lock gates.

I don't think that closing the Thames barrier prevents flooding as the water has to go somewhere, however the flooding is controlled. Flooding fields in essex is far less damaging than flooding people's homes or the houses of parliment. In the past people have been drowned by the Thames flooding and flood defences were built along the river to prevent such a tradgy happening again.

Prehaps an interesting question is why was the UK stupid enough to build their houses of Parilment on a flood plain?

Major rivers are flooding all over the UK. Why is it only the Thames that gets in the news?

[coffeeinbed]

When it's not closed water goes up and down,when it's closed the water only goes downstream to drain away.
The tidal part of the Thames is not tidal anymore.

[coffeeinbed]

Well, sort of not tidal.

[ReallyTired]

In summer when all the locks and thames barrier are open the river thames is certainly tidal. If you live along the thames then you will certainly notice the level of the river go up and down.

The flow of the river thames is only controlled when it needs to be. Most of the year the Thames is tidal otherwise there would be a huge affect on wildlife.

[clam]

"Major rivers are flooding all over the UK. Why is it only the Thames that gets in the news?"
Well, there's been fairly extensive coverage of the flooding caused by the Severn at Worcester and the Parrett and Tone on the Somerset Levels, so it's not just the Thames. And actually, it's not London that's flooded, but many, many communities upstream in Berks and Oxon etc..

They said the barrier is closed at low tide, just before it turns and all comes back in, and I've now drawn a picture so think I get it.

[clam]

And a HousePoint to coffeeinbed for the clearest explanation so far (although everyone has helped Mrs Thicko here )

[HeeHiles]

Why is it only the Thames that gets in the news?

Really? I've been listening to Radio London all day and I haven't heard anything about the Thames lots about ALL the floods ALL over the country.

This comment reminds me of weather forecasters not being able to mention London as viewers go ballistic and say 'Why is only the weather in London that gets mentioned?'

Shhh! No one say the 'L' word fgs!!

[whois]

How do you not get this? Thames is tidal. At low ride, they close the barrier and this prevents the ride waters rising and pushing the water up stream (which would worsen flooding and or actually flood london). The bbc explains it reasonably clearly.

[coffeeinbed]

But yes, level if water goes up and down and the water flows upstream and downstream.
Except when the barrier is closed.

[clam]

By the way, has that bloke who's built an earth barrier all round his house in Somerset managed to stay dry still?

[sarahandmallard]

good visual explanation here

[clam]

If only he was in London, then we'd all know.

[ReallyTired]

I understand the idea of the Thames barrier, but I am in awe of the engineering behind it. I am amazed that whole thing doesn't just get washed away by the storms.

[HeeHiles]

Clam don't be naughty!

[clam]

Jaisalmer "What are those big shiney, domey looking things then ..."

They're to house the hydraulic cylinders.