Herring Bridge

[MY littleboat]

7 hours ago, marshman said:

What and where is the Norfolk Weather Centre - any average figures from them would be  suspect anyway as the weather in W Norfolk is very different to that within the Broadland catchment area.

You will never get any scientific data so why not accept anecdotal evidence, instead of just dismissing it purely because it doesn't agree with what others may believe! The world these days is just too full of experts and people believing they are right, and everyone else is wrong!

I don't think I dismissed it, and apologise if that is the way my post came over, just purely questioned the 'definitive' nature of the statement made, especially when the statistics quoted are not substantiated. It is an opinion, I haven't doubted it, but I would not conclude that these findings in any way diminish that the Herring Bridge may also hold a partial contributory hand in it! As I have said many times, there are those, like yourself and Vaughan who know the rivers, the farming systems and the ways that the land and rivers were managed, but in recent years there have been competing priorities from BA in reduction of cost and dredging necessity, water management with the Environment Agency, building and development targets, discharges from water companies - the list is endless, but the only common theme is that just about every agency, company and authority are putting their hands in the air saying 'not me guv' where the likelihood is, all will have a contributory hand in this - and what really got my goat was the final statement as if to say 'its definitely not that,' when in fact we just don't know but an earlier poster is right - there hasn't been any substantial rain in a few weeks and yet, here we are, still large amounts of flood water.

So no, not a dismissal, just challenging the wording and the nature of that wording, and acknowledging that the contribution is valid but is just, at this stage, anecdotal!

incidentally, this is a UK wide issue and not just linked to Broadland alone so some real joined up thinking is required to understand the issues and we aren't going to solve them on a forum!

[Vaughan]

4 hours ago, grendel said:

7 hours ago, marshman said:

The world these days is just too full of experts and people believing they are right, and everyone else is wrong!

all the more reason not to accept the anecdotal evidence in the face of the inconsistencies

Or perhaps, all the more reason to consider the anecdotal (historical) evidence rather than the spurious theories being put about by various experts.  It is all very well to come up with new theories but they may not stand up against the proven history of how this lowland basin has managed its drainage and water levels, over the centuries since it was artificially re-claimed from a peat bog.  One is tempted to think that the Dutch knew much more about it, back in the 17th century, than we do now.

One way or another, the Broads are now suffering more problems of flooding due to rainwater retention than all of us can remember in our own life-times.

So something, somewhere, has gone badly wrong. 

[batrabill]

 

So:Broads-River-Tidal-Gradients-OctDec23-v-10-Year-Averages (2).pdf

\https://assets.publishing.service.gov.uk/media/659fdb61e96df50014f844a3/East_Anglia_Water_Situation_Report_December_2023.pdf

[MargeandParge]

4 hours ago, FairTmiddlin said:

Be aware that the ceremony starts at 11 am, but ordinary traffic is not expected to be able to use the bridge until after 3 pm.

Is that to let the tide out just incase 

Kindest Regards Marge and Parge 

[duncanholmes123]

On 26/01/2024 at 07:51, MY littleboat said:

Although the poster made detail of being extremely experienced in this field and went to great lengths to describe in pseudo-scientific terms what his impression was, it was neither scientific or can be regarded with any accuracy as to present an accurate picture, readings would be required at all states of tide to calculate volume flow, flow rates and whether the estimated volume in equals volume out - this would also need repeating at different tide-cycle points - simply neap and springs. Whilst I agree that small boat sonar is better than before, it certainly isn't showing current differences (under currents etc) so, whilst this writer, has a well equipped sea-going boat, and has significant detailed experience, it still does not produce any sort of scientific bulk data which can be analysed and assessment drawn for the purposes of flood alleviation.

At university I learnt one thing - evidence sources that are unsupported or opinions should be treated as just that - a hypothesis which needs testing in order to validate or ignoring.

The most worrying aspect of this report are the two final statements;

You are also aware that Oct-Dec the Broads Catchment received 175% of average rainfall. At the same time the North Sea tides have on average been 36% higher since October, reducing a tiny river gradient even further. 

It may be so that rainfall is increased - actually I cannot find reference to 175% and is not supported by data from the Norfolk Weather Centre and did not significantly exceed the 30 year average between 1985 and 2015 source - Climate & Weather Averages in Norfolk, England, United Kingdom (timeanddate.com)

EDP picks a figure of 125% here - Norfolk weather in 2023 was among wettest years on record | Eastern Daily Press (edp24.co.uk)

As for the statement with a calculated tidal percentage - what is that statistic in comparison to, and where the heck has it come from?

Lastly, Keep reposting these unsubstantiated claims really gets in the way of the conversations that are being have trying to help people in the same place as yourself (if indeed YOU are still underwater).

Why suddenly complete what appears to be a thoughtfully written submission with some passive aggressive threat?

 

Wow,

The dissection of my social media post is so unbelievable,

I am a volunteer that spends 100’s of hours a year working in the 3rd sector on various issues and projects on the Broads. I decided at my own time and expense to see if I could use my years of experience in studying water to add some clarity to the conversation around Herring Bridge.

Your attempt to discredit me, my genuine findings/observations is uncalled for, especially as you elevated my observations to something I never claimed them to be, and then attempted to pull them apart based upon that. 

So my right to reply....

1)      I reported findings and observations, not conclusions.

2)      It was a part of social media post, not a scientific paper or a university thesis.

3)      My data comes from verified EA sources stretching back over 10 years or more.

4)      I don’t use the EDP for data. my rainfall data is Broads catchment specific from the EA.

5)      36% higher tide in Great Yarmouth is based on comparing mean high tide data from October to December 2023 with the October – December average from the past ten years. (1.26mAOD v 0.93mAOD)

6)      Restricted water scours, soft riverbeds and seabeds. (hydrology 1-0-1)

7)      Visible Restriction and scouring are clearly obvious at Breydon and Haven Bridges, but completely absent from Herring Bridge

8)      I can find no change in the shape of tidal curves on any of the gauges post Herring Bridge. (restrictions usually create deviation from sine)

9)      Rainfall in the Broads Catchment was extreme.

10)   Specific issues with Overtopping in the Upper Thune are a huge factor the flooding.

11)   The OP from my original post continually trolls the flooding/herring bridge conversation and from my understanding is not under water, hence my slightly catty sign off. 

And most importantly not once did I ever claim to produce any sort of scientific bulk data which can be analysed and assessment drawn for the purposes of flood alleviation. 

Your attempt to discredit me is bad enough but to do it behind a pseudonym is cowardly, you could have discussed my findings without the attempt to discredit me.

All of this while offering none of your own data (other than an edp link), evidence, findings or observations as counter argument.

[batrabill]

Frankly, you (you know who you are and not just Mr pseudo-scientific), deserved that. 
 

You take ideas from people you like without any examination. Show me where you have scrutinised the Bure Hump? 
 

But someone you don’t know posts real observations, not conclusions, and you behave like cult members having their faith questioned. 
 

Shame on you. 

[Smoggy]

In fairness no one discredited the post, they merely pointed out it was not a scientific study but just a anecdotal post of experience/opinion as you have just said yourself, it was sort of shared as some kind of study.

It's a text based forum, don't take it to heart as text never has the context to the reader as it does the poster.

Thank you for your experience. 

[Smoggy]

17 minutes ago, batrabill said:

Oh that’s BS

Thank you for the compliment!

I'm not the one that reposted a faceache post as if it was some sort of study.

[grendel]

On 26/01/2024 at 16:14, marshman said:

Grendel - presumably your comments equally apply to the underlying issue purporting to be the cause of this flooding!!!

quite true.

[CambridgeCabby]

Whilst this thread has contained some interesting information it has sadly evolved into something we try and avoid on the NBN and has turned confrontational , there are always differing opinions on many subjects and healthy discussion is encouraged however this does not mean that confrontational posts will be permitted , please keep it civil to avoid locking or potentially removing this thread 

[Roy]

13 hours ago, duncanholmes123 said:

Wow,

The dissection of my social media post is so unbelievable,

I am a volunteer that spends 100’s of hours a year working in the 3rd sector on various issues and projects on the Broads. I decided at my own time and expense to see if I could use my years of experience in studying water to add some clarity to the conversation around Herring Bridge.

Your attempt to discredit me, my genuine findings/observations is uncalled for, especially as you elevated my observations to something I never claimed them to be, and then attempted to pull them apart based upon that. 

So my right to reply....

1)      I reported findings and observations, not conclusions.

2)      It was a part of social media post, not a scientific paper or a university thesis.

3)      My data comes from verified EA sources stretching back over 10 years or more.

4)      I don’t use the EDP for data. my rainfall data is Broads catchment specific from the EA.

5)      36% higher tide in Great Yarmouth is based on comparing mean high tide data from October to December 2023 with the October – December average from the past ten years. (1.26mAOD v 0.93mAOD)

6)      Restricted water scours, soft riverbeds and seabeds. (hydrology 1-0-1)

7)      Visible Restriction and scouring are clearly obvious at Breydon and Haven Bridges, but completely absent from Herring Bridge

8)      I can find no change in the shape of tidal curves on any of the gauges post Herring Bridge. (restrictions usually create deviation from sine)

9)      Rainfall in the Broads Catchment was extreme.

10)   Specific issues with Overtopping in the Upper Thune are a huge factor the flooding.

11)   The OP from my original post continually trolls the flooding/herring bridge conversation and from my understanding is not under water, hence my slightly catty sign off. 

And most importantly not once did I ever claim to produce any sort of scientific bulk data which can be analysed and assessment drawn for the purposes of flood alleviation. 

Your attempt to discredit me is bad enough but to do it behind a pseudonym is cowardly, you could have discussed my findings without the attempt to discredit me.

All of this while offering none of your own data (other than an edp link), evidence, findings or observations as counter argument.

Thank you for you observations I found your original article interesting and informative I didn’t comment on the issue as I’m not a expert in this field but I’ve been through haven beige many times and the tide runs through that bridge something awful !!! 

[Vaughan]

Hmmm . . . .   Perhaps I am beginning to understand why the admin here doesn't like "mixing it" with Facebook.  A different sort of medium, it seems.

It is a pity as this has become an informed and useful discussion with good opinions being offered.

 

13 hours ago, duncanholmes123 said:

6)      Restricted water scours, soft riverbeds and seabeds. (hydrology 1-0-1)

7)      Visible Restriction and scouring are clearly obvious at Breydon and Haven Bridges, but completely absent from Herring Bridge

We have discussed the official soundings posted here on another thread and I noticed that the considerable scouring at the Haven Bridge occurs upstream of it, as far as the mouth of the Bure. Downstream of the bridge, the bottom flattens out immediately and becomes more shallow.

This (incidentally) also shows the fact that the ebb, on both rivers, is a lot stronger than the flood.

The flow downstream into the harbour slows down greatly as it widens out, so although the volume of water flowing is the same, the speed is very much slower. So even though the Herring Bridge is now a restriction, it would not cause as much scouring, in a much wider harbour area - in my opinion.

I still believe, however, as I described above, that if you restrict the outflow from the harbour area, you must also be restricting the inflow and thus, passing less volume of water through the Haven Bridge.

[Vaughan]

24 minutes ago, Vaughan said:

you must also be restricting the inflow and thus, passing less volume of water through the Haven Bridge.

Taking this suggestion a little further, if you are therefore slowing down the flow of the ebb on the Bure - which is an alluvial river - it will be dropping more of its silt in suspension, especially around the bends in the area of the "Bure hump" and Scaregap farm.

[grendel]

22 minutes ago, Vaughan said:

Taking this suggestion a little further, if you are therefore slowing down the flow of the ebb on the Bure - which is an alluvial river - it will be dropping more of its silt in suspension, especially around the bends in the area of the "Bure hump" and Scaregap farm.

which will necessitate the resumption of the dredging that used to happen and has stopped under the current management.

I would encourage anyone who does touch the bottom while midriver in this area to report it to the Broads authority to start generating a pattern that will be impossible to dismiss as a one off occurrence, and hopefully initiate some dredging action.

[batrabill]

Worth a read. https://www.broads-society.org/post/climate-change-and-the-broads-what-s-at-stake

[grendel]

Ah, I see- so what they are saying is that the river system can no longer be relied upon to remove the water from their catchment areas and that regular dredging is required to improve the outflow of this water.

Quote

Moreover, maintaining and improving the water flow and defences is crucial. This includes ensuring that channels and waterways are kept clear to facilitate smooth water flow. When the sea levels permit drainage, it is imperative that this process is as efficient as possible to maximize the removal of excess water. This requires well-maintained and strategically designed defences that can cope with both the volume and speed of water flow

at least that is what the quote from the article above seems to indicate to me.

[batrabill]

1 hour ago, grendel said:

Ah, I see- so what they are saying is that the river system can no longer be relied upon to remove the water from their catchment areas and that regular dredging is required to improve the outflow of this water.

at least that is what the quote from the article above seems to indicate to me.

That does seem to be the case. However, it is because the fundamentals have changed. Weather and tide. 

[grendel]

1 minute ago, batrabill said:

That does seem to be the case. However, it is because the fundamentals have changed. Weather and tide. 

although I do see that as part of the problem, the lack of dredging / silting in the lower Bure does also seem to be a contributory factor, at least that is how I see it, so that is just my personal opinion.

having run aground once on the lower bure last year a good 30 foot from the bank (well my keel stuck in the mud and took a few seconds of work to free myself), and having seen less than 2 foot under the depth sounder on another occasion mid river and mid tide. anecdotal maybe, but as I personally experienced it, it seems real enough for me.

[JanetAnne]

Rumour has it that one of the BA's dredging rigs is up for sale.

'One careful owner, little used'?

[marshman]

I wasn't aware that they had specific dredging rigs - they all seem to long reach JCB type diggers attached to floating structures and are used for a number of functions. Undoubtedly they are leased and perhaps the lease has come to an end?

And of course the fact may emerge they are just renewing equipment? Seems plausible but without corroboration, we just won't know exactly what is going on.

JA your post suggests they are reducing the number of dredgers - is that fact or supposition I wonder?

[annv]

If the incoming tidal flow was restricted at Yarmouth when high rain fall or high tides by a barrier/gate this would  allow the outgoing tidal flow to continue at double the normal outgoing amount of water from the system. The new bridge abutments would be a ideal place to have this floating barrier. John

[bucket]

This is such an interesting and important thread. Thank you to the OP and those who shared their experience(s) and personal observations.

Like most others, I am no expert! I am however interested in what, if anything, can/might/might not happen next?

I can't dispute that it has been raining a lot since last summer and I accept the report on the higher than average tides over the last few months.......I don't have any reason to doubt Grendel's (and others) observations about the 'Bure hump', somewhere near Stokesby?.......and there is no doubt that the new bridge reduces the river (Yare) width by some margin from what it was 3 years ago when construction began.

My own not scientific observation is that during our 5 weeks syndicate allocation last year, we had a week in April, May, June, September and October, there was only one day where the river level guage showed adequate air draft to get our boat (we need 7 feet) safely through Wroxham, with reasonable confidence of getting back through a couple of days later.

Now, we can't do much about the tides without a tidal barrier can we?..... I read that this has been considered and dismissed previously, and I suspect that one would only be reconsidered, as sea levels continue to rise, if it was needed to prevent flooding of properties, mostly in and around Great Yarmouth and Gorleston.....I don't think me and others getting up to the Rising Sun or not will contribute to decision making too much? It is however important to me!

The Bure hump, (assuming as I do that it exists), may well be a contrbuting factor to the prolonged high northern river levels, particularly with the impact of the reported, far higher than average rainfall, on the catchments of the Bure, Ant and Thurne. And let's not forget the constant pumping of water from farmland back into the rivers. But I have read on here that there used to be a ford at Stokesby? So maybe the Bure hump has existed in some form for quite some time.

The Bure hump shouldn't influence river levels on the Yare and its tributaries. I don't know for instance whether data exists on the rise and fall with the tides of Breydon Water? I have seen photos of the flooding at Reedham for example and the additional rainfall and higher tides will impact the Southern rivers as well as the north, but am I right in thinking that river levels have returned to 'normal' in Reedham (as an example) in between higher tides? That certainly has not been the case at Wroxham (as an example) for months. 

I would think that more water empties through Breydon at Great Yarmouth than does down the Bure, (unscientific personal observation) but does it? If the rise and fall at Breydon has changed significantly since the construction of the Herring Bridge started (3 years ago) then this might point to the narrowing of the river width as a factor. If there isn't a discernable difference at Breydon.......maybe not....others who regularly visit the dark side will know more than me about river levels there over the last 3 months and, indeed, the past 3 years. 

The above, could point to where the current problem, (and me getting under Wroxham bridge any time soon) lies.

I think I have read that the river span of the new bridge is greater than that of the Haven Bridge. Is that correct or have I made it up? I know that flow capacity is determind by volume and not just river width.....but at this location, flow is also influenced by river bed height above sea level, because it won't drop any lower than that, so you can only effectively dredge to that level anyway.....and wouldn't an additional river width restriction, restrict the ebb as well as the flood?

One thing I do know though is that the new bridge, whether or not it is having an influence on river levels, is not going away, anytime soon.

The point I am trying to make is that there are many factors that influence broads' river levels. All of the above (and probably many more) may or may not be a factor...but is anyone looking at everything in the round? I don't know.

Sustained flooding of properties on the riverbanks this winter must be heartbreaking for those who live there, but are there enough properties affected to bring about an investigation.....again I don't know.

If the Bure hump is growing and can be shown to be a significant contriburary factor to the sustained high northern river levels then the solution seems relatively straight forward.....although I suspect not cheap.....and if the hump was dredged effectively.....could that lead, without significant additional strategic dredging, to reduced, at times unnavigable river depths further upstream? 

We could well point to previous failings of planning, maintenance and human impact on climate change.....and I am sure many will. But we are where we are.

If there is to be a solution, the benefits, going forward, must outweigh the cost.

And there lies the problem...the costs could well prove to be far greater than the benefits and the solutions, let's say for a moment that the new bridge is a major issue and has to go.....or removing the hump would devastate the local colony of critically endangered vegan newts, are unaffordable or unpalatable (or both)......

The solution for me regarding getting up to the Rising Sun is far more attractive to the authorities isn't it........I will just have to get a smaller boat.

 

 

[MauriceMynah]

Many moons ago I asked if the bridge clearance at Beccles old bridge had changed significantly in the last 10, 15 years. My logic was simple, if it has,  then it's an overall broads problem. If not then it's a Bure problem.

This question has never had an answer.

[batrabill]

Bucket, the meeting on Friday at Hickling may shed some light on this.

There must be within EA the data on average river heights at all locations -  so someone must know the answer to the question if the rise is everywhere or more in the Northern Broads.

Re the Bure Hump. The shallows at Stokesby have been there for a long long time. I think there is a hard bottom, so it's not a sediment problem, so I don't think anyone is claiming that is the Bure Hump, or that it has changed in recent times.

 

On a recent thread I posted the depth maps for Yarmouth to Stokesb,  from EA  and there wasn't  a specific area where it was shallower - ie in that data there was no visible hump, other than some shallowing at Stokesby.  Recently the problem has been described by those who think there is a Bure hump as something along the lines of " a shallowing from Stokesby to Yarmouth" this is due to lack of dredging in some eyes.

Frustratingly, there must be people in the EA and Ba who have the data.

I think when a BA hydrologist did come on here some years ago he didn't support the Bure Hump theory. Cant find his contribution. I think he pointed out that shallows stop the incoming tide and specifically salt incursion. So dredging the Stokesby - Yarmouth stretch may have other consequences....

One thing I am absolutely certain of, that river systems are complex and simple solutions are hard to find.

[AndyTBoater]

Just for info - if you want to go to the meeting be prepared for a bit of a walk

Duncan Baker has just put this up on his FB page

https://www.facebook.com/photo?fbid=786247036654560&set=a.356876166258318

Not sure they were expecting more than a few people there for this.