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smitch6

Southern Broads Extremely Low :o

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Never seen the broads this low before..........

we went to look at a new mooring we're getting in OB today

the chap is leaving as he said his sailing boat keeps grounding, so the OH and me thought lets pop down and have a look.....

when we got there the bottom of the broads at the maltings was actually uncovered and i thought ooo it does get low.

we spoke to a cpl of ppl and they all said never seen it this low before and we've been here 20 years.

so we thought we'd pop up to Geldeston and see if our little boat in Rowan was ok and this is what we were confronted with...

even boats at Beccles were leaning badly

2018-12-16 12.27.33.jpg

2018-12-16 12.27.29.jpg

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Yet another excellent example of why the Broads are in dire need of a major dredging operation. It makes you ask the questions, why do we pay so much in tolls, and what are they wasting it on if not doing much needed dredging?.

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It's what a strong wind in the wrong direction does especially when there is a big low pressure area in the north holding the tide away, dredging would just make it run out quicker.

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well it ran out fast enough when the sea levels were low enough, so I guess that answers the question on whether the lower reaches around lowestoft need dredging.

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If you had a dyke with a depth of 4fft alws, and you dredged it to 8ft alws, the surface of the water will still be the same height above ground. The more you dredge out, the more sea water will come in to fill the rivers back to their original level in relation to the ground. Also, if the rivers had regular dredging, the immediate effect would be less, and would`nt take as long to go back to its original level.

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Who wants to see 8' draught boats at Geldeston? If you regularly go aground on a normal tide then dredging is an issue but at £45 a grab load, even doubling the dredging programme would decimate the navigation budget!!

And all to achieve no extra benefit other than messing up the natural flow - alter the flow excessively and you could well have other downsides with no extra benefit! Not an option IMHO - for what its worth!!

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Is that what it generally costs? - £45 per grab load?  That's a heck of a lot of grabs to clear out the lower Bure down to the yellow post.  Mind you, if the 'B.A' had kept on top of it as it was handed over to them it would just be minimal on going maintenance

Griff

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Sadly we have all seen the results of piecemeal maintenance on water courses all over the country and the resulting flooding over the last decade or two. 

Regards

Alan

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Controlled flooding upstream seems to be the name of the game, as in some cases it prevents damage downstream - we are quite lucky around here as we generally have lazy rivers often with marshes to spill over into even if a few senseless farmers still try and pretend otherwise!!

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Marshman, I have a genuine question. As you know it is my belief that thorough dredging for the whole system is needed, and also, as I know, you hold a counter view.

My view is from the standpoint of a summer visitor from 1966 to 1992 and a boat owner and more regular visitor from'92 to today. I have discussed this with some who live and run businesses on the broads. I have witnessed changes, and while I have accepted that flood alleviation may well have had a significant impact on water levels, I cannot ignore the lack of dredging as another major factor. 

Your posts regularly imply that such dredging would have little or no effect on the water levels, yet, unless I'm missing something, rarely are your implications backed up with possible reasonings . I suspect that there is perhaps a certain level of "devils advocate", which is fair enough, I like to have my thoughts questioned, it makes me question them myself, but your objection to the lack of dredging being a reason is so solid that I wonder why.

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yes , from what I can see, when the sea levels are low enough, the tide does recede, there were substantially lower levels at horning and stalham too, indicating that given low enough levels at breydon, the water can escape fast enough, which leads me to surmise that possibly it is not additional dredging that is required (although i too thought this previously). this would seem to indicate that sea levels hold a major factor in the water levels on the upper northern broads, ie that if the levels are high on Breydon, the water doesnt flow out., this doesnt mean that the dredging is unnecessary as the depths should be maintained sufficient for navigation, but it does seem to indicate that the air draft at Potter Heigham Bridge is more a factor of the sea levels than the dredging (or lack of).

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14 minutes ago, grendel said:

ie that if the levels are high on Breydon, the water doesnt flow out.,

On a calm day when the tide is starting to flood on Breydon but has not turned on the Bure, you can actually see a step in the water level, going diagonally across just a few yards upstream of the river junction. It can be a difference of several inches. Anyone else seen this?

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2 minutes ago, Vaughan said:

On a calm day when the tide is starting to flood on Breydon but has not turned on the Bure, you can actually see a step in the water level, going diagonally across just a few yards upstream of the river junction. It can be a difference of several inches. Anyone else seen this?

No, i have`nt, but then i do live around 250 miles away lol. 

Seriously though Vaughn, as someone who has been working on the Broads for decades, you, and people like you, have personal experience of just exactly how the Broads and rivers have changed over decades, and as such, i always  value your thoughts. 

As for Potter Heigham old road bridge, i stand by my belief (through scientific evidence) that it IS caused by structural issues, and the fact that the Eastern Coastline of the UK is sinking gradually.  A couple of years back, Neil Oliver on his tv programme "Coast" went diving in the North Sea with a group of scientists, where they were looking at tree stumps on the sea bed. Also, Gryff Rhys Jones did a programme called "Rivers" where he was going around rivers all over the UK, and when on the Fens, reported on a scientific survey by people from Cambridge Universities, where they were measuring a pole on land and stating that the whole of the area, including the coastal regions was gradually sinking. A preferential view in favour of a personal theory is NOT proof, but scientific evidence taken over decades, maybe even centuries IS. 

We all know some people believe the BA can do no wrong, and are always honest and right, but sometimes, as we`ve all no doubt had to do at times, people have to swallow their pride and accept they are wrong.

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1 hour ago, Vaughan said:

On a calm day when the tide is starting to flood on Breydon but has not turned on the Bure, you can actually see a step in the water level, going diagonally across just a few yards upstream of the river junction. It can be a difference of several inches. Anyone else seen this?

Yes that is a regular occurrence if you arrive at the right time.

Fred

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1 hour ago, SPEEDTRIPLE said:

No, i have`nt, but then i do live around 250 miles away lol. 

Seriously though Vaughn, as someone who has been working on the Broads for decades, you, and people like you, have personal experience of just exactly how the Broads and rivers have changed over decades, and as such, i always  value your thoughts. 

As for Potter Heigham old road bridge, i stand by my belief (through scientific evidence) that it IS caused by structural issues, and the fact that the Eastern Coastline of the UK is sinking gradually.  A couple of years back, Neil Oliver on his tv programme "Coast" went diving in the North Sea with a group of scientists, where they were looking at tree stumps on the sea bed. Also, Gryff Rhys Jones did a programme called "Rivers" where he was going around rivers all over the UK, and when on the Fens, reported on a scientific survey by people from Cambridge Universities, where they were measuring a pole on land and stating that the whole of the area, including the coastal regions was gradually sinking. A preferential view in favour of a personal theory is NOT proof, but scientific evidence taken over decades, maybe even centuries IS. 

We all know some people believe the BA can do no wrong, and are always honest and right, but sometimes, as we`ve all no doubt had to do at times, people have to swallow their pride and accept they are wrong.

I think the problem with Potter just highlights the changes in levels rather than just being a major issue in its own right, I am no scientist or expert in anything but as a school boy back in the 1950 s one of the things I was taught and has since been backed up with 60 odd years angling experience is that due to friction water flows at a faster rate on the surface than it does at lower levels being slowest on the river bed, this allows sediment to drop out while still flowing but more important when it meets an obstruction like the hump at GY it sets up an undercurrent which deposits even more sediment increasing the size of the hump but it also raises the water level both where it crosses the obstruction and further back upriver, this is why dredging is necessary and without it the obstruction will continue to grow thereby increasing the water levels even more.

This is just my opinion of course not based on any scientific profiling but purely observation of the affect on tackle and fish  while fishing various running waters.

Fred

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I think the pole referred to in the fens is at whittlsey mere, the land has not sunk it has eaten itself IIRC, when the land was drained and the peat dried out the air got in and set the microbes at work and the result is the fields get lower and lower, a lot of the roads and houses around there sit high above the fields on firmer ground because they were built on rhoddons which were old river beds where the deposited silt is far more solid that the surrounding peat.

I would imaging a few of the straight line villages around the broads are on similar ground for the same reasons.

The post in question is surprisingly high seeing as it was buried to ground level when it was put in, there is now a new one beside it and the old one is on a concrete base.

These are sketchy fact so may be liable to the odd trumpism (or cock up) as it's quite a few years since I was there.

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2 hours ago, Vaughan said:

On a calm day when the tide is starting to flood on Breydon but has not turned on the Bure, you can actually see a step in the water level, going diagonally across just a few yards upstream of the river junction. It can be a difference of several inches. Anyone else seen this?

I can see quite a blockage in that area at a certain time when a load of boats queue up to see this phenomenon! :default_jumelles:

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is that not just the local equivalent of the severn bore?, where the incoming tide and the outflowing river meet? or is it some other phenomenon?

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2 hours ago, rightsaidfred said:

I think the problem with Potter just highlights the changes in levels rather than just being a major issue in its own right, I am no scientist or expert in anything but as a school boy back in the 1950 s one of the things I was taught and has since been backed up with 60 odd years angling experience is that due to friction water flows at a faster rate on the surface than it does at lower levels being slowest on the river bed, this allows sediment to drop out while still flowing but more important when it meets an obstruction like the hump at GY it sets up an undercurrent which deposits even more sediment increasing the size of the hump but it also raises the water level both where it crosses the obstruction and further back upriver, this is why dredging is necessary and without it the obstruction will continue to grow thereby increasing the water levels even more.

This is just my opinion of course not based on any scientific profiling but purely observation of the affect on tackle and fish  while fishing various running waters.

Fred

This is what I understand to be true, that a hump at the Bure mouth does hold some water in the system. But it ignores the incoming tide. This is what JP, reporting what BESL said, 

 

"In reality, the bed level near to the Bure mouth is raised and currently prevents extra water (saline water) from entering the system at high tide. If the channel were to be dredged from the mouth of the river, flood levels would in fact become worse. 
Dredging the river further upstream from this point would possibly reduce water levels but by such a small amount that the overall effect would be negligible."

The reference to flood levels does confuse things, which is frustrating, because what we are interested in is average levels. I'm hoping to get better info.

But, my core point remains, any raising of the river bed works both ways - it reduces the amount of water entering the system on the flood tide.

One thing I am certain of, hydrology is a very tricky subject.

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