Dredging - Lowe Bure - Lack Of Maintenance

[riverman]

Just my unwanted thoughts.

After the flooding on the Somerset levels in 2014 and the massive backlash regarding the lack of dredging, I strongly doubt the EA would disapprove of any comprehensive dredging programme, be it in BA jurisdiction, CRT or anyone else's. Its not BA bashing to put the onus on them instead of the EA.

For an operation of their scale, 26000 cube is pathetic. Truly abysmal. However in their defence, from personal experience, getting rid of even 1000 cube is a challenge. 

Excusing the slightly hippy-ish term and bareing in mind this comes from someone who does dredging but what's required is a genuinely holistic approach. Nurturing better relationships with land owners to allow for easier spoil deposition and possibly active involvement, because you can only dredge if you've got somewhere to put it. Working with the WMA and Norfolk Rivers Trust to try to store water and slow the flow coming from North Norfolk would be another good idea.

And slightly less hippy-ish, pulling there finger and stopping the holiday camp that is BA's works team would help. We were sheet piling in Oulton Broad back in March and in the 2 weeks were on site, they removed no more than half a dozen barge loads of mud, an utterly pointless waste of time and money.

 

 

 

[NeilB]

I would have thought with the strongish tides on the lower sections they could use some sort of water injection or ploughing.  This loosens the silt enough to be carried out by the tide with no soil to dispose of.  

[Regulo]

I think Goodchild's used some sort of pump aboard a barge to do this at their marina entrances? Don't know how successful or not it was. 

[Bytheriver]

On 17/12/2023 at 21:10, riverman said:

Just my unwanted thoughts.

After the flooding on the Somerset levels in 2014 and the massive backlash regarding the lack of dredging, I strongly doubt the EA would disapprove of any comprehensive dredging programme, be it in BA jurisdiction, CRT or anyone else's. Its not BA bashing to put the onus on them instead of the EA.

For an operation of their scale, 26000 cube is pathetic. Truly abysmal. However in their defence, from personal experience, getting rid of even 1000 cube is a challenge. 

Excusing the slightly hippy-ish term and bareing in mind this comes from someone who does dredging but what's required is a genuinely holistic approach. Nurturing better relationships with land owners to allow for easier spoil deposition and possibly active involvement, because you can only dredge if you've got somewhere to put it. Working with the WMA and Norfolk Rivers Trust to try to store water and slow the flow coming from North Norfolk would be another good idea.

And slightly less hippy-ish, pulling there finger and stopping the holiday camp that is BA's works team would help. We were sheet piling in Oulton Broad back in March and in the 2 weeks were on site, they removed no more than half a dozen barge loads of mud, an utterly pointless waste of time and money.

 

 

 

At the time of the Somerset Level floods in 2014 I was a Flood Warden in Dorset ( The scheme in the South West is organised & funded by EA ) There is a full report into cause & solutions ( Updated 2023 ) here https://www.gov.uk/government/publications/somerset-levels-and-moors-reducing-the-risk-of-flooding/somerset-levels-and-moors-reducing-the-risk-of-flooding#:~:text=In early 2014%2C the Somerset,area of 65 square kilometres.

[marshman]

Thats quite interesting and I note the Bridgwater Barrier work is going to happen - as a result some 13000 homes and many business premises will be protected. But if you read the current objectives, it is designed to stop a high tide coming in and flooding the Somerset Levels which in many cases are below sea level But there are not direct parallels with the situation here surely ? 

We have seen extensive flooding of marshes and some "marginal" agricultural land but has life been in danger?  Indeed the main effect has been the flooding, with fresh water, of what is often just summer grazing marshes - my guess is that in summer 2024  they will still be full of cattle as the grass will regrow and the land will be back to normal.

I also believe few properties were directly affected, other than those that you would expect, and there have not, to my knowledge, been reports of the " new" river walls being breached. I am sure the EA are well aware of whats happening and if I recall, did put out a report somewhere where I cannot find anymore ( just found it!!)

Whats is worth remembering, and highlighted in this report, and which I have mentioned before, is keeping the balance right - removing silt further downstream may enable the salt surges to encroach further inland and everyone knows what happens, I suspect, if you increase, salinity too much. It impacts the whole eco system , and the first impact is on the fish population and then beyond, in fact it could destroy much of the Broads as we know it.

As I frequently comment, beware of what you wish for and the Laws of Unintended Consequences.

[grendel]

surely the problem with the salt surges is that if the incoming salt surge cant properly drain away, the next incoming tide pushes it further upriver, then the next and the next, if the bure freely drained, then the salt would get to a point, then be flushed out, and the next incoming tide it would get to the same point and be flushed out, rather than the current salt surge being pushed further upstream with every incoming tide.

Just my thoughts I know, the BA are using your theory as a reason not to dredge, but (and I dont know this for a fact) were the salt surges as bad or worse when the bure was dredged?

[kpnut]

It was interesting that the report said something along the lines of keeping the banks clear of encroaching reeds is necessary to aid the proper flow of water. I agree. Quickest way to have a silted up river system turning into wetland carr is to slow the water down at the edges. 

[floydraser]

I am totally unqualified in these matters but there is an invitation by Griff at the start of this thread to debate so:

The covid enquiry demonstrates that in places, there are authority folk pondering actions of great importance to large numbers of people. While the plates are spinning, these people may become just that; a large number and not individual lives. I worked at an agency where the boss referred to workers as his “stock”.

Visiting Birmingham University in the summer I saw students demonstrate experiments in a large, stainless steel tank about 6ft by 4ft by 2ft deep. In it were layers of coloured sand. It was tilted up at a slight angle and water was made to flow from the upper end to the lower, exposing the layers. So they were learning about rivers, flooding, geology etc. But from who? Lecturers who already have years of experience and the benefit of historical records. All funded by organisations including the EA.

All this convinces me that somewhere there are a group of people who know EXACTLY what the situation is. They probably know the depth and contour of every river bed. But as long as these people keep their heads down and the information remains ambiguous, people like the BA can spout what they like and they can all get away with doing nothing. Isn't that how they got away with doing nothing at Somerset?

Be gentle..

[Cheesey69]

I work for a similar semi government agency and I can tell you they know exactly what is needed but also what is obtainable with the current funds and that is rub. 

[rightsaidfred]

Problem these days is we have a plethora of experts and a few individuals with practical knowledge, two things to bere in mind salt water is heavier  than fresh water  and due to friction the water at the bed flows slower than the surface.

Fred

[Bytheriver]

12 hours ago, Cheesey69 said:

I work for a similar semi government agency and I can tell you they know exactly what is needed but also what is obtainable with the current funds and that is rub. 

I was at the well attended EA East Coast & Estuaries Flood Seminar in Ipswich in September & it was clearly stated the amount of work that can be done is on a cost /benefit/ residential properties protected basis with each scheme having to bid for funds 

 

[Paladin]

2 hours ago, Bytheriver said:

I was at the well attended EA East Coast & Estuaries Flood Seminar in Ipswich in September & it was clearly stated the amount of work that can be done is on a cost /benefit/ residential properties protected basis with each scheme having to bid for funds 

 

It seems sight has been lost of the simple fact that the Broads Authority has no responsibility under those criteria. Their legal obligation is to protect the interests of the Navigation.

[Smoggy]

There's more graduates than proper knowledable folk at the EA these days so don't hold too much hope, on the great ouse my uncle was with the EA but started in the days of great ouse drainage board and then NRA before the EA came into being, when they did a load of work on St.Ives lock they had loads of trouble with concrete cracking and couldn't work out why things were moving when it should all be solid, my then retired uncle knew full well the surrounding mooring edges couldn't be tied into the lock and weir structure as it was built on a bed of elm and effectively floats on the ground water pressure so the whole structure changes elevation when the water level changes,  similar when St.Neots lock was refurbed and they took a crane in beside the pen during the work, the rest of that season the lock had emergency patches holding the side up until a full rebuild could be carried out the next year, as soon as he saw the crane there he said it would collapse the pen, the poor blokes in the bottom at the time had a get out quick when it started moving, no-one had spec'd the max crane weight for ground that had been waterlogged since the lock was originally built.

Very little dredging happens at all now only the shoals that build below locks and then it's dumped in the river just downstream as it's hazardous waste and can't be put on land, the land floods with the same water that runs over the river bed so how is that less hazardous? Of course if you spend a fortune on a previously un-needed flood defense you get to stand beside it for photos in the local paper and claim credit for it, that doesn't happen with routing dredging that saves the need for flood defence in the first place.

[BroadAmbition]

And there’s the key to it all right there

- Routine dredging/ maintenance or in our case the lack of it on the lower Bure.

IF the blessed authority had simply maintained what they inherited in the first place then we would be in a far better situation 
 

They only have themselves to blame but it is the people of the Broads are paying the price

Griff