Extra High Pressure.

[TheQ]

Just seen the weather forecast,  they are predicting a high air pressure deeper than anything seen in the last 50 years. 

This will lower the water levels considerably,  if the northerly wind is not to strong.  If it happens,  it's likely to be followed by a fish kill when the salt water rushes to refill the broads. 

[rightsaidfred]

Levels still very high at the moment with rivers overtopping at Wroxham, Horning and Potter Heigham, I don`t know what the Southern side is like.

Fred

[Simondo]

Fairly high in south side but nothing alarming and dropping now

[TheQ]

Wales had the highest air pressure since 1957 overnight, since high pressures generally move eastwards I would expect our highest to be in the next couple of days..

[marshman]

Our figures at the moment are around 1047 and moving on into the week, look to decline a bit -  I would also expect it to impact water levels but surprisingly its only reducing levels a bit and not as much as many would hope. This shows how many factors affect Broadland tides and their levels!

There are two which may be relevant - I think normally the upstream marshes take a lot of the water when tides are at their highest as they have been, but this winter the "sponge " effect has been reduced as they are already very wet. Some of the few reedcutters are very concerned that levels this year are going to impact what small amounts are still cut annually which does have a knock on effect.

The other point is that the other day, out in mid Norfolk, I noticed even there, there was a lot of water about. Hawk and Owl Trust by Fakenham for example, have had to close temporarily as they are inundated. Whilst we have not  had a huge amount of rain of late in Broadland they may have had more there and its all got to pass through and out through Haven Bridge!! Everywhere is wet and all the extra has to run off as land is pretty saturated.

We need 2/3 weeks of dry weather, preferably with drying easterly winds, to dry everything out, but its not on the cards - yet!!

[MauriceMynah]

Sorry Marshman, but I must comment.

There is a third option as to why the water seems so reluctant to leave. It has been the same story elsewhere in the country after prolonged periods of rain. Where the dredging has been left to one side there have been problems with flooding, saturated land etc. etc.

[Polly]

However, should the amount of fresh water held upstream not help prevent a salt water surge? 

[MauriceMynah]

It might, it might not, but either way it seems to be another small piece of evidence indicating the effects of the lack of dredging.

[SPEEDTRIPLE]

23 minutes ago, MauriceMynah said:

It might, it might not, but either way it seems to be another small piece of evidence indicating the effects of the lack of dredging.

Sorry John, but I'm going to have to agree with you there........ AGAIN 😂. 

[SPEEDTRIPLE]

1 hour ago, marshman said:

Our figures at the moment are around 1047 and moving on into the week, look to decline a bit -  I would also expect it to impact water levels but surprisingly its only reducing levels a bit and not as much as many would hope. This shows how many factors affect Broadland tides and their levels!

There are two which may be relevant - I think normally the upstream marshes take a lot of the water when tides are at their highest as they have been, but this winter the "sponge " effect has been reduced as they are already very wet. Some of the few reedcutters are very concerned that levels this year are going to impact what small amounts are still cut annually which does have a knock on effect.

The other point is that the other day, out in mid Norfolk, I noticed even there, there was a lot of water about. Hawk and Owl Trust by Fakenham for example, have had to close temporarily as they are inundated. Whilst we have not  had a huge amount of rain of late in Broadland they may have had more there and its all got to pass through and out through Haven Bridge!! Everywhere is wet and all the extra has to run off as land is pretty saturated.

We need 2/3 weeks of dry weather, preferably with drying easterly winds, to dry everything out, but its not on the cards - yet!!

Hi marshy, 

I would have thought easterlies would hold the levels back up river so not allowing the water to escape?. 

[JennyMorgan]

19 minutes ago, SPEEDTRIPLE said:

Hi marshy, 

I would have thought easterlies would hold the levels back up river so not allowing the water to escape?. 

A good Easterly can also force the water out of the North Sea or hold back water from the Atlantic. We'll know on the day!

[rightsaidfred]

2 hours ago, marshman said:

Our figures at the moment are around 1047 and moving on into the week, look to decline a bit -  I would also expect it to impact water levels but surprisingly its only reducing levels a bit and not as much as many would hope. This shows how many factors affect Broadland tides and their levels!

There are two which may be relevant - I think normally the upstream marshes take a lot of the water when tides are at their highest as they have been, but this winter the "sponge " effect has been reduced as they are already very wet. Some of the few reedcutters are very concerned that levels this year are going to impact what small amounts are still cut annually which does have a knock on effect.

The other point is that the other day, out in mid Norfolk, I noticed even there, there was a lot of water about. Hawk and Owl Trust by Fakenham for example, have had to close temporarily as they are inundated. Whilst we have not  had a huge amount of rain of late in Broadland they may have had more there and its all got to pass through and out through Haven Bridge!! Everywhere is wet and all the extra has to run off as land is pretty saturated.

We need 2/3 weeks of dry weather, preferably with drying easterly winds, to dry everything out, but its not on the cards - yet!!

And that will only get worse with all the additional housing development planned around the NDR etc.

Fred

[marshman]

Easterly winds tend to less humid I think and it tends to be a more drying wind - the westerlies we see pop straight out off the Atlantic and carry a lot of moisture.

The water exiting through Haven Bridge drains an enormous area of Norfolk and Suffolk - which is why they continue to spend a lot of money to protect the low lying areas of GY and Gorleston. I believe they are lifting the river banks once again and spending yet more money in the Harbour.

I am not getting dragged into the dredging issue again but it is hugely problematical. The present theories seem to be that you try and keep as much as you can upstream and release it in a slower, more controlled manner - don't shoot the messenger but that seems to be the trend!!!!! But dredging the main rivers does increase the tendency to increase salt water surges - and thats frowned upon too, but these continue to push further inland every year as tides get bigger - thats not fiction but a general fact. Even over the last 15 years, they have continued to push further in. Not sure where the most recent ones got to up the Bure but is usually somewhere between Ant Mouth and Horning Hall. No doubt the EA will ask if you tell them!!

[Meantime]

I'm a strong advocate of more dredging but I also think a barrier in Great Yarmouth is needed. When heavy rain is forecast the barrier could be closed at low water. It would then hold back the incoming tide leaving space on the upstream side for the rain water to run off into the Lower Bure. As the tide starts to drop, open the barrier and let the Lower Bure drain out.

What we are seeing more and more in recent times is fluvial flooding, rather than tidal flooding. The Thames barrier is raised far more often at low tide to prevent fluvial flooding than it is at high water to prevent tidal flooding.

Such a barrier could also be raised to prevent salt surges.

[SPEEDTRIPLE]

3 hours ago, EastCoastIPA said:

I'm a strong advocate of more dredging but I also think a barrier in Great Yarmouth is needed. When heavy rain is forecast the barrier could be closed at low water. It would then hold back the incoming tide leaving space on the upstream side for the rain water to run off into the Lower Bure. As the tide starts to drop, open the barrier and let the Lower Bure drain out.

What we are seeing more and more in recent times is fluvial flooding, rather than tidal flooding. The Thames barrier is raised far more often at low tide to prevent fluvial flooding than it is at high water to prevent tidal flooding.

Such a barrier could also be raised to prevent salt surges.

Think how much that would cost, something none of the mainstream authorities would want to pay towards, as they have more important things to pay for, such as all expenses payed trips on jets to climate change conferences etc, and huge salaries, bonuses,  and expense accounts.  Also, imagine how long it would take, with all the discussion groups, feasability studies, environmental impact conferences, and just general other wastes of tax payers money.

Personally i think it`s a good idea, if it worked as hoped?.

[SwanR]

5 hours ago, EastCoastIPA said:

I also think a barrier in Great Yarmouth is needed. When heavy rain is forecast the barrier could be closed at low water. It would then hold back the incoming tide

But if you did that, what would be the effect along the coast down to Lowestoft?

[vanessan]

28 minutes ago, SwanR said:

But if you did that, what would be the effect along the coast down to Lowestoft?

Your caravan might need a propeller and a rudder! 

[TheQ]

17 hours ago, EastCoastIPA said:

I'm a strong advocate of more dredging but I also think a barrier in Great Yarmouth is needed. When heavy rain is forecast the barrier could be closed at low water. It would then hold back the incoming tide leaving space on the upstream side for the rain water to run off into the Lower Bure. As the tide starts to drop, open the barrier and let the Lower Bure drain out.

What we are seeing more and more in recent times is fluvial flooding, rather than tidal flooding. The Thames barrier is raised far more often at low tide to prevent fluvial flooding than it is at high water to prevent tidal flooding.

Such a barrier could also be raised to prevent salt surges.

They did look at a barrier some years ago, but there is a problem. There is less water going out of the exit to the North sea than comes down the rivers.

Where does the rest go, ?

Under Yarmouth from the airfield to the exit, GY is built on a gravel spit and leaks like a sieve..

You build a barrier and you could well wash away GY, which may or may not be good news..

[Smoggy]

29 minutes ago, TheQ said:

You build a barrier and you could well wash away GY, which may or may not be good news..

As long as it takes haven bridge with it I'm fine with it.

[MauriceMynah]

I didn't reply to Marshman to restart my hobby horse about dredging, only to suggest that it was POSSIBLY another reason why the water seems so reluctant to go away. I would say that it's something I feel the relevant experts should investigate, but I'm not going to rake up all my old arguments here (this time)

I suppose my feelings are running just a little high just now but that's because I have just had a 4 week holiday on my boat but was unable to leave the Hickling side in all that time where I had looked forwards to having my winter holiday going from pub to pub enjoying all the festivities of the season. I was on my boat from about the 17 Dec to mid Jan. I was basically stuck on my home mooring for the duration. My boat needs 6' at PH bridge. not exactly drought conditions. 

If this prolonged high pressure period reduces the water level back to it's current norm, all well and good, but if it fails to achieve that my rant will return at max volume! 

[JanetAnne]

 

1 hour ago, TheQ said:

They did look at a barrier some years ago, but there is a problem. There is less water going out of the exit to the North sea than comes down the rivers.

Where does the rest go, ?

Under Yarmouth from the airfield to the exit, GY is built on a gravel spit and leaks like a sieve..

You build a barrier and you could well wash away GY, which may or may not be good news..

As long as they raise PJ's chippy first! The rest seems a fair sacrifice  and seaside water parks are very on trend these days.

[rightsaidfred]

2 hours ago, MauriceMynah said:

If this prolonged high pressure period reduces the water level back to it's current norm, all well and good, but if it fails to achieve that my rant will return at max volume! 

Still barely 6`0" at Wroxham 

Fred

[marshman]

It has finally gone down a bit from the levels of the weekend - but in overall terms it is only marginal!  The boat was dripping everywhere - out and in!!!!!

[vanessan]

8 hours ago, TheQ said:

You build a barrier and you could well wash away GY, which may or may not be good news.

🤔

[CambridgeCabby]

For the past five weeks I’ve been unable to get under Ludham Bridge , I need 8ft so can get through at about 7ft 10 on the downstream board , yesterday was 7ft 3 , I wonder if the BA is going to revise its bridge heights which still claim 8ft 6 as the average high water level at Ludham , the past few years I would say it was nearer to 8ft 2 at high water levels