dredging rivers

[Phil Ambrose]

Way way way back in the day there was a fellow called Cornelius Vermuyden who came over from Holland and helped us reclaim the lands of the Fens and the Isle of Axholme where I am from. Now even though there are a multitude of dykes and drains I recall the River Trent still over topping when I was a little girl. Whether any of that engineering was ever taken to other parts of the country I do not know. But I do know that in the Isle the local drainage board and local farmers keep their drainage channels clear and dredge them every year............ but then the geology of the land is also naturally sandy.................I'lll leave you to make of this what you will

Cornelius Vermuyden built the first sluice at the Denver Complex in 1652 as part of the Cambs Fen drainage scheme in part as drainage and in Part to preserve navigation from Cambridge.

Phil

[ditchcrawler]

OK I stand corrected. As someone who lives approximately 600ft above sea level, however you measure it, the thought of people willingly living 12ft above, even high tide level, just strikes me as madness.

 

George ex nb Alton retired

Like me and everyone else within about 20 miles of Gt Yarmouth in all directions.

[Alan de Enfield]

Like me and everyone else within about 20 miles of Gt Yarmouth in all directions.

 

20 miles East of Gt Yarmouth is at sea level

[furnessvale]

Like me and everyone else within about 20 miles of Gt Yarmouth in all directions.

I rest my case.

 

George ex nb Alton retired

[Radiomariner]

But if onrust advocates to raise the banks, to increase three volume of the channel, the same effect is achieved by dredging. By removing silt from the bottom, you make the river deeper.

 

But than you all know that, really...

 

No. If the river bed is below sea level, dredging it deeper will make no difference to the flow, Raising the banks will, providing they are raised to a height above sea level, allow the level of the river to be higher and increase the river capacity and flow

 

I believe dredging could help in some areas and make things worse in other areas. It neets clever people indeed to work out what to do and where

 

The truth of this whole problem is the phenominal amount of rain, wind direction rising seasonal high tides (sea level) even higher, modern ideas on building drainage farming etc., and nobody realising what would happen when all this accumulated. Where was the "Visionary" we needed? Ah yes, I remember his plans now,. "Build a big Ark"

Edited February 10, 2014 by Radiomariner

[Guest]

[Bee]

Even if its above sea level it makes no difference, you have to lower the surface of the water to take the excess, the only way to do that is to dredge pretty much the whole length of the river, dredging cannot work.

[DaveC]

It's all down to plastic carrier bags. When they get banned things will get back to normal.

 

 

Dave

[nb Innisfree]

Even if its above sea level it makes no difference, you have to lower the surface of the water to take the excess, the only way to do that is to dredge pretty much the whole length of the river, dredging cannot work.

To drain an area it has to have somewhere to drain down to and that somewhere, ultimately, has to be the sea, the higher the area is above the sea the faster it drains. If that area is at or near sea level then it has to be pumped up to above it.

 

Another prob with draining peat based areas is shrinkage, on the Middle Level, draining over the centuries has lowered the ground 4 metres so it is now below sea level and river embankments have had to be continuiusly raised. Solve one prob and another is created.

[furnessvale]

Another prob with draining peat based areas is shrinkage, on the Middle Level, draining over the centuries has lowered the ground 4 metres so it is now below sea level and river embankments have had to be continuiusly raised. Solve one prob and another is created.

I thought London, Manchester and many other places were desperate to find places to dump their rubbish, even moving it the length of the country by train.

 

I can think of one or two low lying bits of land that could use a bit of fill.

[Jambo]

An interesting assessment of where the situation has got to:

 

http://therivermanagementblog.wordpress.com/2014/02/09/scramble-for-blame-serves-no-one/

 

...The cumulative outcome of this is that the human interest stories on the Somerset Levels dominates the news, and the narrative that has emerged is one of a lack of dredging leading to flooding. The government, against advice of the Chartered Institute for Water & Environmental Management, leading hydrologists and flood scientists, has embraced the dredging narrative and committed to dredging the levels. There are two fundamental problems with the way this issue has played out in the media.

Firstly it is highly doubtful dredging rivers in general, or the Tone & Parrett specifically, would have any appreciable effect on flood events of the magnitude we have witnessed recently. To use one of my trademark analogies, it’s a little like drinking two bottles of wine and suggesting the brandy chaser was the thing that made you drunk. It’s possible it might be the case, but it’s highly unlikely. Stretching the analogy (as is my wont) and speaking purely of my own alcohol tolerance, I could drink 1 or 2 glasses of wine, with or without a brandy and be coherent. If I drink 4 glasses of wine, I’ll likely be hammered either way. It is only in the very specific case of my consuming precisely 3 glasses of wine that drinking, or not drinking a brandy will have any difference whatsoever. That is the essential problem with dredging; increasing the river conveyance only has an effect for a very specific flood event which would just over-top the un-dredged river (and thus may not over-top in the presence of dredging). It’s a little more complex in managed systems like the Levels, but the magnitude of event is most relevant issue. This one was far, far too big...

 

 

And from that link above a couple of expert views on the impacts of dredging:

 

http://www.sciencemediacentre.org/expert-reaction-to-somerset-flooding/

[Radiomariner]

I have been listening to the radio (BBC 2) and am pissed off with the "Who is to blame" culture we seem to have in this country. What is done is done, what has happened has happened, we should accept that and ask "What can we do about it?" If it is necessary, as some people believe, to blame somebody, it should take place AFTER the problems have been sorted and with the added benefit and clarity of 20-20 hindsight.

Edited February 10, 2014 by Radiomariner

[Phil Ambrose]

I have been listening to the radio (BBC 2) and am pissed off with the "Who is to blame" culture we seem to have in this country. What is done is done, what has happened has happened, we should accept that and ask "What can we do about it?" If it is necessary, as some people believe, to blame somebody, it should take place AFTER the problems have been sorted and with the added benefit and clarity of 20-20 hindsight.

Lord Smith was asked by a stroppy reporter where the blame lay regarding the flooding, he simply said "the weather" (good boy)

Phil

[Alastair]

Lord Smith was asked by a stroppy reporter where the blame lay regarding the flooding, he simply said "the weather" (good boy)

Phil

I was dead impressed with him in that interview. Pickles comes across as a complete idiot by comparison.

[mark99]

I have been listening to the radio (BBC 2) and am pissed off with the "Who is to blame" culture we seem to have in this country. What is done is done, what has happened has happened, we should accept that and ask "What can we do about it?" If it is necessary, as some people believe, to blame somebody, it should take place AFTER the problems have been sorted and with the added benefit and clarity of 20-20 hindsight.

 

I tend to agree.

 

Near us there has been a tradegy where some poor souls tried to keep their property dry, used two pumps and the CO fumes killed their child and put them both in hospital.

 

Out comes a friend or neighbour ranting and blames the government etc for letting this family down and the whole country down for the floods and leading to this death.

 

OK I can understand the shock but it's always some-one elses fault.

[Phil Ambrose]

 

I tend to agree.

 

Near us there has been a tradegy where some poor souls tried to keep their property dry, used two pumps and the CO fumes killed their child and put them both in hospital.

 

Out comes a friend or neighbour ranting and blames the government etc for letting this family down and the whole country down for the floods and leading to this death.

 

OK I can understand the shock but it's always some-one elses fault.

Also like the woman (from a "big" house whose drains were backed up and complained loudly that Anglian Water would not supply her with a Portaloo, so she had to hire her own

Phil

[boathunter]

...

 

The bloated bureaucracy of the EA is also a problem, especially when compared to similar agencies on the continent. Our British management style ends up with people who have little understanding or experience of what they are managing, often with disastrous or expensive results.

On a small local scale (I work in the fens near Mildenhall in Cambridgeshire), I often buy a bacon buttie from a local van and meet a 75 year old chap. When we have too much rain and something locally floods the EA don't know what to do! This chap has spent an entire lifetime controlling the water in the area and knows every sluice and ditch and how it all works, but they won't employ him. Worse still, being a nice chap he has on many occasions offered to teach someone what he knows for nothing but they don't take him up on his offer. What happens when there's flooding is the people in charge drive around purposefully in their vans looking like they're out there attending to it but nothing happens because they have no local knowledge. Sometimes they make it worse!

 

Eventually some old boy phones the nice chap who at 75 dons his waders and oilskins and goes to sort it out. All on the quiet, for no pay, to help his friends and neighbours. What will happen when he gets too old for this is a worry.

 

[edit] Part of the problem is that Harry is such a gentle, lovely and considerate man (his chickens live in the house with him) that people who don't know him or are quick to judge, take him as simple, which is far from the truth.

Edited February 10, 2014 by boathunter

[furnessvale]

On a small local scale (I work in the fens near Mildenhall in Cambridgeshire), I often buy a bacon buttie from a local van and meet a 75 year old chap. When we have too much rain and something locally floods the EA don't know what to do! This chap has spent an entire lifetime controlling the water in the area and knows every sluice and ditch and how it all works, but they won't employ him. Worse still, being a nice chap he has on many occasions offered to teach someone what he knows for nothing but they don't take him up on his offer. What happens when there's flooding is the people in charge drive around purposefully in their vans looking like they're out there attending to it but nothing happens because they have no local knowledge. Sometimes they make it worse!

 

Eventually some old boy phones the nice chap who at 75 dons his waders and oilskins and goes to sort it out. All on the quiet, for no pay, to help his friends and neighbours. What will happen when he gets too old for this is a worry.

It's obvious they won't listen to him. Does he have a degree...........No..............He knows nothing!

 

George ex nb Alton retired

[boathunter]

It's obvious they won't listen to him. Does he have a degree...........No..............He knows nothing!

 

George ex nb Alton retired

Quite so, I added a bit about him in my post above saying much the same. He even worries they'll find out he's doing it and get in trouble, but he can't let his community down and he knows if push came to shove there'd be a minor riot if anyone so much as worried this truly lovely man.

[peterboat]

An interesting assessment of where the situation has got to:

 

http://therivermanagementblog.wordpress.com/2014/02/09/scramble-for-blame-serves-no-one/

 

 

And from that link above a couple of expert views on the impacts of dredging:

 

http://www.sciencemediacentre.org/expert-reaction-to-somerset-flooding/

Great link says what I said all along thames barriers for all rivers and when all the money has run out print some more is this trolling?

 

Peter

[Radiomariner]

Thanks for the links Peterboat. Projects my understanding of the situation precisely !

 

The home owners on the now flooding Thames areas must be really gratified to know that their sacrificial floodinge is enabeling Londoners to get to work without getting their feet wet.

Yes,a bit too cyinical, I know flooding in the city would be catastrophic probably with horrendous loss of life.

[Phil Ambrose]

Thanks for the links Peterboat. Projects my understanding of the situation precisely !

 

The home owners on the now flooding Thames areas must be really gratified to know that their sacrificial floodinge is enabeling Londoners to get to work without getting their feet wet.

Yes,a bit too cyinical, I know flooding in the city would be catastrophic probably with horrendous loss of life.

Doubt there would be loss of life but would provide the impetus to take river matters seriously, it would really focus the mind of the powers that be.

Phil

[luctor et emergo]

Thanks for the links Peterboat. Projects my understanding of the situation precisely !

 

The home owners on the now flooding Thames areas must be really gratified to know that their sacrificial floodinge is enabeling Londoners to get to work without getting their feet wet.

Yes,a bit too cyinical, I know flooding in the city would be catastrophic probably with horrendous loss of life.

Ohh, seeing as the houses pf parliament and The City are near the river, there could be a bonus.

Can we quickly organise a Lawyer Symposium in the O2??

[GUMPY]

I find this conjecture about saving London rather strange as all the weirs on the Thames have been fully drawn since December and at the moment apart from the Jubilee river not a lot can be done to alter the flow.

All the Jubilee river will do is relieve flooding in Maidenhead not London.

[Tony Brooks]

I find this conjecture about saving London rather strange as all the weirs on the Thames have been fully drawn since December and at the moment apart from the Jubilee river not a lot can be done to alter the flow.

All the Jubilee river will do is relieve flooding in Maidenhead not London.

 

That seems to be the EA line over the last few years but unless they have shut Boulters weir we now have two "rivers" feeding water down where as before we only had one. Without the Jubilee there would be some flooding in Maidenhead but a lot more on the low fields (with their water courses) above Maidenhead would have flooded and ten across the town moor and out to Bray as the old flood relief scheme intended.

 

Sorry, I just do not see how providing a second large water course can do anything but move the problem downstream.