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The Boston Barrier


Naughty Cal

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Flood defences - you stop the tide/river flooding one place but the water has to go somewhere. I'm not convinced that we need to keep the water out rather that work around the inevitable.

 

Perhaps its time to start building raised housing? In the Isle of Axholme there are a few houses near the Trent that have the garage at ground level and living quarters second level and upwards. Sound idea if you ask me.

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yes I agree, flood water needs to go somewhere and by putting up barriers it's just going to get pushed to the next village that has no defence's

 

That's not really the case with tidal defences. If the wall or barrier is big enough then the tide will just stop at that point rather than further inland, and shouldn't put places nearer to the sea at greater risk of flooding that they already are.

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Houses on stilts? This is now mandatory for new builds on The Broads, when applying for planning you must apply to both the local planning authority and the Broads Authority who insist buildings within a certain distance are built in stilts so accommodation is above flood risk level, makes sense to me

Ref Black Sluice Drainage Board, we lived at East Heckington and were sent a map which showed the area that would be flooded and act as flood water containment, it was within the confines of the South Forty Foot and the Maud Foster and was several hundred square kilometers in area.

When we sold up, to get the sale we had to agree to pay a one off insurance premium for the purchaser as cover for the (unlikely) event that flooding would occur. We were about 8 miles from Boston but there was not a contour line between us and the Haven. The premium was only £90-00, bargain I thought

Phil

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that's interesting about the one off insurance payment Phil, not heard of anything like that before

We had to pay an insurance for buying our first house at an undervalue from my Dad, it was to protect against any future claim by the seller. if I recall it was around the £90 mark the same as Phil.

 

Money for old rope!!

As far as the barriers goes, good to see some more progress in the Boston area. I wonder if I ever will see the Fen Waterways Link my lifetime though?!

Edited by gazza
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We had to pay a one off insurance too when we sold up.....house being just under 3 miles from the River Trent (Keadby) on a natural flood plain. We also had to sign a declaration that it not flooded there in our lifetime. We moved out the end of October 2012 and in December 2012 the Trent went over the banks at Keadby......

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We had to pay a one off insurance too when we sold up.....house being just under 3 miles from the River Trent (Keadby) on a natural flood plain. We also had to sign a declaration that it not flooded there in our lifetime. We moved out the end of October 2012 and in December 2012 the Trent went over the banks at Keadby......

Result!

Phil

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It is nice to see that they have actually listened to the concerns of local boaters voiced over the previous plans and amended them in a way that facilitates their needs.

 

What will happen to the boat when the gate is up and the boat (or you) is outside in the storm.

 

The boating group asked for a lock have a look at Cardiff.

Edited by oboat
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What will happen to the boat when the gate is up and the boat (or you) is outside in the storm.

 

The boating group asked for a lock have a look at Cardiff.

 

The barrage is permanently in position in Cardiff, so a lock is needed (actually I see there are three, available 24 hours a day).

 

By contrast the Boston barrage would only be used when a very high tide is expected. There is no lock at the Thames Barrier, which has much more traffic, so it would be hard to see the justification for a lock at Boston. If you were an incoming narrowboat you would need to get to Grand Sluice well before HW anyway. And it would be pretty sheltered anyway downstream of the barrage, you would just tie up to the dock wall if necessary.

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The barrage is permanently in position in Cardiff, so a lock is needed (actually I see there are three, available 24 hours a day).

 

By contrast the Boston barrage would only be used when a very high tide is expected. There is no lock at the Thames Barrier, which has much more traffic, so it would be hard to see the justification for a lock at Boston. If you were an incoming narrowboat you would need to get to Grand Sluice well before HW anyway. And it would be pretty sheltered anyway downstream of the barrage, you would just tie up to the dock wall if necessary.

 

I think you miss the point.

 

Its not just narrowboats going in or out!

 

One of the factors re a surge is a very high on shore wind. Plus a high tide. & or high fluvial flows.

 

If I was late back for whatever reason & in a GRP boat and a big steel fishing boat was on tow & could not pass through, I think they call it confetti.

 

Obviously the good folks at Burton Waters have not been thinking it through???????

 

But going to the next step, Why do you think the EA have put the last little note on the film. Think about it before you reply.

 

Clue Pumps

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I think you miss the point.

 

Its not just narrowboats going in or out!

 

One of the factors re a surge is a very high on shore wind. Plus a high tide. & or high fluvial flows.

 

If I was late back for whatever reason & in a GRP boat and a big steel fishing boat was on tow & could not pass through, I think they call it confetti.

 

Obviously the good folks at Burton Waters have not been thinking it through???????

 

But going to the next step, Why do you think the EA have put the last little note on the film. Think about it before you reply.

 

Clue Pumps

 

Thank you. I agree a lock (ie the barrier having two gates in line?) would be nice, I just think it would be hard to justify. Compare for example London, where navigation stops when the barrier, and all the other smaller barriers further downstream, are shut

 

Do you mean the "business as usual" quote from the Black Sluice IDB?

 

If so, then the fluvial flow around high tides comes from pumping (if any) at Black Sluice, as Grand Sluice will be shut. A feature of this scheme is that the Black Sluice pumps can't be operated for long when the new barrier is shut (capacity 60 cumecs, for four hours into a stretch of water roughly 2000m long x 75m wide = nearly 6m of water). But the impression I get from various other documents is that those pumps are not very effective anyway, ie the Black Sluice can drain adequately via gravity discharge at lower states of the tide, and that the proposal is to decommission the pumps. Is that right?

 

http://www.boston.gov.uk/CHttpHandler.ashx?id=13787&p=0

http://lincolnshire.moderngov.co.uk/documents/s11316/Black%20Sluice%20Consultation.pdf

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Thank you. I agree a lock (ie the barrier having two gates in line?) would be nice, I just think it would be hard to justify. Compare for example London, where navigation stops when the barrier, and all the other smaller barriers further downstream, are shut

 

Do you mean the "business as usual" quote from the Black Sluice IDB?

 

If so, then the fluvial flow around high tides comes from pumping (if any) at Black Sluice, as Grand Sluice will be shut. A feature of this scheme is that the Black Sluice pumps can't be operated for long when the new barrier is shut (capacity 60 cumecs, for four hours into a stretch of water roughly 2000m long x 75m wide = nearly 6m of water). But the impression I get from various other documents is that those pumps are not very effective anyway, ie the Black Sluice can drain adequately via gravity discharge at lower states of the tide, and that the proposal is to decommission the pumps. Is that right?

 

http://www.boston.gov.uk/CHttpHandler.ashx?id=13787&p=0

http://lincolnshire.moderngov.co.uk/documents/s11316/Black%20Sluice%20Consultation.pdf

 

 

 

 

 

 

 

 

 

Thanks Simon

 

In a word. Yes.

 

But to take London first.

My understanding is that as it is now closing so often, that it IS becoming a real problem, which would have been much greater when the river was more commercial. As a matter of interest WLM for London was proposed at the time of build, but the PLA were opposed due to bridge heights particularly Chelsea and Hammersmith.

 

Black Sluice

Your 60 cumecs is very interesting as is the 4 hours, where did you get this from?

I have not seen any modeling for this, or what happens if the 60/4 will not work?

 

Is that total volume with the gate up from last low water?

or

With WLM, operating?

 

Some volume could also be available from over toping back over Grand Sluice (but not a good idea)

 

Do you know how long the 2013 over topping went on for?

 

As I read it (in simple terms) with the barrier up and tide kept out the pumps would not be required. But EA have not said this.

 

My concern or observation is, if the tide is excluded, closing the river to navigation how often will it take place.

 

As we know officialdom always errs on the side of caution (and rightly so), thus in this regard it is not the number of times the pumps have run in the past, but the number of times they have been on standby to run, that is important in regard to lifting the barrier and closing the navigation.

(The other potential and it is only a potential, is that the EA could find it convenient to lift the barrier to avoid dredging, as per the new extra 50mm on top of Grand Sluice gates.)

 

I can’t believe the EA have not taken all this into account!

 

Is this the real reason they will not build the lock?

Have the EA worked out that if a lock is provided, water retained behind it could occupy channel volume that could otherwise be used to accept gravity discharge from the Black Sluice Navigation, when the barrier is lifted to exclude sea water?

(The original requested Hobhole location increases available volume, could use the Hobhole pumps, the new and extra Boston Dock gate would not be needed and dock availability could be marginally improved).

 

This development alone is a fundamental reason for a “Transport Work Order” Enquiry.

 

If the above tide exclusion model were to be used, with a lock I would see the temporary elevation of water level as nothing more than inconvenient for high sided craft as at H W Spring tides now.

 

In terms of economic justification

 

A Managed Water Level in the Haven had been an integral part of the studies and plans for the Boston Barrier until the recent EA shift of focus.

 

The benefits of MWL to tourism and inland navigation are well illustrated by Cardiff Bay which now has over 1,000 boats (Take a look on Google Earth.) which call the bay home.

 

Boston desperately needs this type of economic diversification.

 

I would see the greatest economic benefit to Boston as coming from visiting sea going craft as at Cardiff and Swansea, not to mention the Copenhagen example given in the WLM Study.

 

 

In terms of argument for the lock.

 

IF my comments above are so, then the case for a lock is magnified.

 

At the Lincoln CC debate on the subject it was claimed that the barrier would only close about once in ten years.

That was also the prediction for London back in the 70’s.

Clearly we now have a new set of conditions, which should mean the lock situation must be reviewed.

 

I could go on but I think that is enough for today.

It is nice to see that they have actually listened to the concerns of local boaters voiced over the previous plans and amended them in a way that facilitates their needs.

 

How did they do that ?

 

This is not what the PWG asked for.

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Thanks again. The four hours was just a guess on my part, ie if the barrier (as currently designed) is closed then it might be shut for 2 hours either side of high water.

 

My understanding of the various documents on Black Sluice is that gravity discharge is adequate to drain it, either side of low water. The total capacity for gravity drainage matches the flow capacity of the channel inland.

 

I do see the case for holding the water inland at a fixed level, in effect moving grand sluice downstream a couple of km.I don't quite understand if that level is low enough for Black Sluice to drain under gravity, or if pumping is needed (and then gravity discharge though the lock around low tide).

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