Tidal surge

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steve yates

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Was going to move my wee boat back across the creek to the sailing club piles, but my staging at benfleet moorings was under a foot of water :) so I coukdnt actually reach it. (well i could have waded but I couldnt disconnect the power as the cable was threaded below the staging) There was a tidal surge of .85m on top of the almost spring tide of 6.1m Got me thinking, what are the largest tidal surges we see in the estuary, aside from ones driven by excessivle large storms that hit here?
 
I'm not clear why you want to know the largest tidal surges excluding those driven by 'excessive large storms'. It's a combination of pressure (high and/or low) and the winds associated with pressure gradients, that causes tidal surges. Without storm-like weather systems there wouldn't be a substantial surge.

If you don't exclude 'excessive large storms', then the highest recorded are, I believe, those of the 1953 floods, shown (for the English coast only - the Netherlands was also badly affected) on the map below (about 5m above predicted tide for Benfleet, I guess). (We don't know whether there were higher ones prior to reliable recording.)

Don't panic now, but there's no saying that there couldn't be a higher surge than the 1953 one. Note also that the 1953 floods were caused by the surge on top of a high tide, but it wasn't the highest of high tides. :oops:

page6image3237376384

https://forms2.rms.com/rs/729-DJX-565/images/fl_1953_uk_floods_50_retrospective.pdf
 
LittleSister said:
I'm not clear why you want to know the largest tidal surges excluding those driven by 'excessive large storms'. It's a combination of pressure (high and/or low) and the winds associated with pressure gradients, that causes tidal surges. Without storm-like weather systems there wouldn't be a substantial surge.

If you don't exclude 'excessive large storms', then the highest recorded are, I believe, those of the 1953 floods, shown (for the English coast only - the Netherlands was also badly affected) on the map below (about 5m above predicted tide for Benfleet, I guess). (We don't know whether there were higher ones prior to reliable recording.)

Don't panic now, but there's no saying that there couldn't be a higher surge than the 1953 one. Note also that the 1953 floods were caused by the surge on top of a high tide, but it wasn't the highest of high tides. :oops:

View attachment 128079

https://forms2.rms.com/rs/729-DJX-565/images/fl_1953_uk_floods_50_retrospective.pdf
Click to expand...
In the December 2013 surge tide the heights in some East Coast areas were greater than those of 1953. Although the defenses are better now.

Www.solocoastalsailing.co.uk
 
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Plum said:
In the December 2013 surge tide the heights in some East Coast areas were greater than those of 1953. Although the defenses are better now.
Click to expand...

And, perhaps more importantly, the plans/arrangements and communication technology for responses to flooding (and other large scale) emergencies, and the warnings of impending flood risk .

A lot of the problems and fatalities in 1953 were, I read some time ago, due to shortcomings in those areas.
 
Plum said:
In the December 2013 surge tide the heights in some East Coast areas were greater than those of 1953. Although the defenses are better now.

Www.solocoastalsailing.co.uk
Click to expand...
I believe that that was so on the north Norfolk coast? As for Benfleet what we saw the other day is about as big as we get usually, it all depends where & when the surge coincides with High water, back in 2013 a few of us were down the club that night and it came into the clubhouse, Strange thing was we had two HW 's about 15 minutes apart where the surge peaked started to go out & dropped then came back in again really fast, quite un nerving.
To put it into perspective on the road by dauntless gate it was up to my knees. In 53 it topped the flood boards so would have been over my head at the same spot.
 
The deaths at Sea Palling were when the sea broke through the sand dunes, there were no defenses as such then. My current house was left on an Island I wouldn't have bought it otherwise. Now Sea Palling and a couple of miles either way have big concrete defenses with gates closed at forecast high water events.

At Hunstanton, the waves overtopped the then embankments as I believe it did down in Essex..

Just looked at the Horning sailing club web cams and the water is a couple of inches below the Key heading.. That's tidal effects and it's 19miles inland by river... about 18 inches higher than it should be.
 
LittleSister said:
And, perhaps more importantly, the plans/arrangements and communication technology for responses to flooding (and other large scale) emergencies, and the warnings of impending flood risk .

A lot of the problems and fatalities in 1953 were, I read some time ago, due to shortcomings in those areas.
Click to expand...
Let's not forget the effect of WW2. Essentially 6 years of neglect of flood defenses, both coastal and inland. Somewhat countered by the availability of a large body of conscripts and surplus equipment that could be mobilized to plug breached defenses. I believe there are still places where flood barriers have surplus military vehicles embedded in them.

Flood defences are less likely to be breached these days, but if ever they are, it might take years to restore the situation - if ever. We don't have the manpower or equipment to do what was done in 1953.
 
AntarcticPilot said:
. We don't have the manpower or equipment to do what was done in 1953.
Click to expand...
Have you been asleep for the last 60 years?
I do not know the population increase since then - I could Google it. But you only have a short drive to a few building sites to see the hundreds of hydraulic excavators & other earth moving equipment that is now available at a moments notice.
I could hire them my digger for a few bob if they are short. Might even throw in a graft for you, free, as part of the deal,-- if you know how to work one ;)
 
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WoodyP said:
The tidal Nene goes up to Dog in a Doublet near Whittlesey, the tidal Ouse goes up to Denver, near Downham Market, the tidal Welland goes up to Spalding. All these are a long way in land, and navigable. I rest my case.
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And all of those Cambs / NW Norfolk have had thejr defences substantially reinforced and heightened since 1953, along with other E coast sea defences. Also the cause of the flooding there in 1953, as Gladys wrote, was overtopping rather than failure there as well.

Peter
 
Keith 66 said:
I believe that that was so on the north Norfolk coast? As for Benfleet what we saw the other day is about as big as we get usually, it all depends where & when the surge coincides with High water, back in 2013 a few of us were down the club that night and it came into the clubhouse, Strange thing was we had two HW 's about 15 minutes apart where the surge peaked started to go out & dropped then came back in again really fast, quite un nerving.
To put it into perspective on the road by dauntless gate it was up to my knees. In 53 it topped the flood boards so would have been over my head at the same spot.
Click to expand...
Thats useful, I was asking to make sure I had enough in my lines for big spring high tides combined with a surge.
There was no storm of any sort anywhere near, so I guess the surge the other day travelled down from Scotland?
 
We've had northerlies for several days, that and easterlies always increases the sea level on the south east coast of the UK..
For us on the Norfolk Broads the wind direction and air pressure normally has more effect than Rain..

Low air pressure=== High water,
Northerly ===== High water,
Spring Tides==== High Water,
A Storm==== maybe high water
Get any two and we're paddling..
Get three and some may be swimming
Get all four and a lot will be swimming..
 
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