Word of warning - Knostrop Lock, Aire & Calder

[Nick D]

We have been making our way towards Leeds and the L&L over the past few days waiting for the river levels to come down. We spent last night at  Woddlesford and travelled north to Knostrop Lock early this afternoon to wait for it to turn green.  When we got there at 1.30 it was at least 3 inches into green so we went through but almost immediately regretted the decision. The flow coming downstream was very powerful so much so that my 42hp engine was almost standing still. I would have turned round and gone back, but my wife was already ashore having previously tried to moor up and being unable to get back on board.  I eventually made it to Leeds lock where she was waiting for me and the traffic light light was unsurprisingly flashing red. We spluttered our way into the Royal Armouries basin where we are now safely moored.  The CRT Northern  Office is just across the river from here so I paid them a visit to ask why it was apparently safe to pass through Knostrop into such difficult conditions.  The CRT and Leeds council have been doing some flood alleviation work which has only just been completed and other boaters have reported that the markers at Knostrop are now inaccurate.  It's a shame they haven't acted on thIs sooner as we could have been much more badly affected by the conditions today and I'm posting this so that other boaters can be aware if they are travelling northwards on the A&C. DO NOT TAKE NOTICE OF THE RED/AMBER/GREEN warning levels at Knostrop!

[Jen-in-Wellies]

The flood alleviation work has changed the river here a lot. When I went through in May it was still in progress. Knostrop Flood Lock, which is in my old Nicholsons's, between Knostrop and Leeds Lock now no longer exists, so the flow rate hitting Knostrop lock will be different. You could see the remains when I went by. Can't remember if there was a weir associated with the flood lock as it is five years since I last went there and I have no memory of that bit, but if there was, then it is now gone and this will change the levels. Definitely something CaRT need to look at.

Jen

[Robbo]

Note don't take any notice of the markers at River Lock on the L&L as this has the same issue as well.    I'm glad a lot of boaters have moaned - what did they say when you complained?

[Robbo]

7 hours ago, Jen-in-Wellies said:

The flood alleviation work has changed the river here a lot. When I went through in May it was still in progress. Knostrop Flood Lock, which is in my old Nicholsons's, between Knostrop and Leeds Lock now no longer exists, so the flow rate hitting Knostrop lock will be different. You could see the remains when I went by. Can't remember if there was a weir associated with the flood lock as it is five years since I last went there and I have no memory of that bit, but if there was, then it is now gone and this will change the levels. Definitely something CaRT need to look at.

Jen

The main issue is that the weirs at Knostrop and outside the Armouries can drop so the river level drops but the flow is still in flood conditions.

[Nick D]

27 minutes ago, Robbo said:

Note don't take any notice of the markers at River Lock on the L&L as this has the same issue as well.    I'm glad a lot of boaters have moaned - what did they say when you complained?

They said that another boater had reported the same problem a little while ago and it was something they needed to look into although there was no time limit specified. Watch this space (probably for some time)!

[Robbo]

55 minutes ago, Nick D said:

They said that another boater had reported the same problem a little while ago and it was something they needed to look into although there was no time limit specified. Watch this space (probably for some time)!

Well they’ve known for a while this would be an issue as the weirs have taken a few years to install!  

 

Its an an easy fix  remove the gauges, put the locks in “flood” flashing light mode and manually lock the gate at the river lock at granary wharf.

Edited October 26, 2017 by Robbo

[Jen-in-Wellies]

1 hour ago, Robbo said:

The main issue is that the weirs at Knostrop and outside the Armouries can drop so the river level drops but the flow is still in flood conditions.

Clever idea those weirs. Agree that the usual red/amber/green flood markers are going to be useless with such an arrangement. No excuse for CaRT not getting their act together seeing as the work went on right outside their door.

Jen

[Robbo]

Here is a photo of the weir in question, two have been lowered so the third one doesn’t have any water going over it.   You can see from the photo of the weir (the one without the water going over) how high the weir is meant to be in normal river levels.  

[Robbo]

Looks like their is a incident at Knostrop weir where they are still doing work on the non-working one.  Involves a capsized working boat and sadly they may have been a fatality with one of the workers.      I think knostrop lock may be been closed off in the meantime as it's just next to the weir.

[Robbo]

Just had a update from a fellow neighbour boater.

The worker was on the lower side of the weir in a safety boat removing rubbish and debris from the base of the weir when they got to close and the boat filled up with water, capsized trapping one of the workers in the boat due his lifejacket self-inflating plus the flow of the water from weir.  The other one in the boat managed to swim away.    The guy is currently in a induced coma.

Edited October 31, 2017 by Robbo

[Nick D]

It just goes to show what the force of water can do. Last week we stood on the bridge and saw beer barrels and large calor gas canisters being tossed around at the bottom of the weir like balloons.  Hope the guy pulls through.

[HBROK]

http://www.yorkshireeveningpost.co.uk/news/man-in-serious-condition-in-hospital-after-boat-overturned-on-river-aire-in-leeds-1-8832531

[Robbo]

 

Man dies after boat capsizes on River Aire in Leeds

A 60-year-old man has died after a boat he was working in capsized on a river in Leeds.

He was working with another man in the boat when it went over on the River Aire, at Thwaite Gate in Stourton, on Monday.

The man, who was from Hull, was taken to hospital in a serious condition and died on Wednesday evening.

Police said they were investigating the incident along with the Health and Safety Executive.

http://www.bbc.co.uk/news/uk-england-leeds-41845268

[Nick D]

That is very sad news

[Quaysider]

Having read through the "logic" written above, it makes sense to me now why the other weekend when we left Granary Wharf (with the river just dipping into the amber) the turn above the new weir towards Clarence dock/lock 1 ) was underpant scary...  we'd been stuck there until lunchtime waiting for the level to drop into the amber to make a run for it...   once through lock 1 and back onto the river, it was quite a lot faster than we'd have liked.

https://photos.app.goo.gl/oCGHQP64bqnI7zzB3

[Robbo]

11 minutes ago, Quaysider said:

Having read through the "logic" written above, it makes sense to me now why the other weekend when we left Granary Wharf (with the river just dipping into the amber) the turn above the new weir towards Clarence dock/lock 1 ) was underpant scary...  we'd been stuck there until lunchtime waiting for the level to drop into the amber to make a run for it...   once through lock 1 and back onto the river, it was quite a lot faster than we'd have liked.

https://photos.app.goo.gl/oCGHQP64bqnI7zzB3

 

 

Please put a complaint into CRT regarding.   The river was actually more likely in flood conditions at the time.   The gauge in the photo above is now useless.

[pearley]

Were the gates to Clarence Dock open then? On the couple of times I've been there with the river in flood the gates have been chained shut. 

[Robbo]

5 minutes ago, pearley said:

Were the gates to Clarence Dock open then? On the couple of times I've been there with the river in flood the gates have been chained shut. 

The gates are to protect Clarence dock and the armouries, as the river water level can now be controlled these gates don’t seem to be used.

Edited November 3, 2017 by Robbo

[Quaysider]

25 minutes ago, pearley said:

Were the gates to Clarence Dock open then? On the couple of times I've been there with the river in flood the gates have been chained shut. 

nope - they were open... I suppose it's OK if you know the flow will be fast - we were going downstream... I'd imagine it would have been a slow journey were we going the other way - at Castelford where we turned right on to the calder we did have to put on a few more revs to make the turn safely but that was about 3.3/4 hours later so both had dropped a bit further by then.

[pearley]

2 hours ago, Robbo said:

The gates are to protect Clarence dock and the armouries, as the river water level can now be controlled these gates don’t seem to be used.

 

2 hours ago, Quaysider said:

nope - they were open... I suppose it's OK if you know the flow will be fast - we were going downstream... I'd imagine it would have been a slow journey were we going the other way - at Castelford where we turned right on to the calder we did have to put on a few more revs to make the turn safely but that was about 3.3/4 hours later so both had dropped a bit further by then.

At the end of  November 2010 we were stuck at Lemonroyd in the ice for 7 weeks. Once released from the ice in mid January we made our way to Leeds only to find the flood lock at Knostrop closed. Walking up to Leeds, the gates go Clarence Dock were chained shut. We had actually booked and paid for 2 months mooring in the dock. Once the gates were opened we made our way to Clarence Dock and stayed there for the next few weeks, being booked into the drydock at Skipton (aka black hole of Culcutta) a few weeks later. During that time the gates of the lock were shut at least once. 

Actually I rather like Leeds and had been looking forward to spending Christmas there but the weather put paid to that. 

[magictime]

We emailed the local CaRT office to flag up the concerns raised in this thread and ask for advice, as we're planning to cruise from Stanley Ferry to Leeds in the next day or two. They were kind enough to get back to us with a detailed and reassuring reply, which I see no reason not to share here:

Our Principal Water Engineer has looked into the recent reported incident mentioned on Canalworld discussion forum and we can confirm the water level upstream of Leeds weir had already peaked and was dropping at the reported time of the incident; Similarly, the level upstream of Knostrop had peaked and was also starting to drop slowly. Both locks will have been correctly indicating that the river level was green and safe to navigate.  However, then the river level between Knostrop and Leeds Lock suddenly increased after the last recorded passage at Knostrop.  In about 30 minutes the river level increased by 200mm.  It appears the craft was travelling towards Leeds and during the journey the large storm discharge culverts, which has been in place for many years, which flow into the river just below Leeds weir started to discharge a flood from the drainage in North Leeds.  We have no way to predict these occasional large sudden inflows from the storm discharge below Leeds weir; as far as we can tell our water level warning systems (SCADA) worked correctly.

 If I can give you a brief explanation of the weirs operation; The weirs remain up and replicate the previous navigation weirs, unless being tested, up to the point where a large flood event is developing. Then Leeds City Council drop their weir crests to lower the water level through Leeds and down as far as Knostrop lock.  This provides extra flood storage and an increased depth of flow at the weirs so the storm event can pass through Leeds without going over flood walls in a significant flood event.    At the point when the weirs are dropped the river will already be high into red and all the locks will have gone into warning mode. It is not the case that the weirs now go up and down all the time to keep river levels near normal, whilst the flow increases.   I understand that it takes Leeds City Council two hours to slowly drop the weir crests, to avoid a large surge of water flowing downstream.

 Please note that the traffic light at Knostrop lock only shows green if it a Lock Keeper is present. With the lock in user operation, it will show amber and allow craft to pen themselves through. Our SCADA team confirm the lock was in user operation at the time of the reported incident. The traffic light will flash red when the upstream level gets too high, however it can't predict when this will happen, it only gives information based on the current level. The customer who reported the incident we believe must therefore be referring to the water level gauge board being in the green section.

 We can confirm that the new Leeds flood alleviation weirs have not yet been operated, except for testing and will not do so until very high water levels. Up to that point they provide a similar length and height to the original weirs.

The Leeds Flood Alleviation Scheme is led by Leeds City Council in partnership with the Environment Agency and the following is a link to their website which you may find of interest http://www.leeds.gov.uk/residents/Pages/FloodAlleviationScheme.aspx

[Robbo]

1 minute ago, magictime said:

We emailed the local CaRT office to flag up the concerns raised in this thread and ask for advice, as we're planning to cruise from Stanley Ferry to Leeds in the next day or two. They were kind enough to get back to us with a detailed and reassuring reply, which I see no reason not to share here:

Our Principal Water Engineer has looked into the recent reported incident mentioned on Canalworld discussion forum and we can confirm the water level upstream of Leeds weir had already peaked and was dropping at the reported time of the incident; Similarly, the level upstream of Knostrop had peaked and was also starting to drop slowly. Both locks will have been correctly indicating that the river level was green and safe to navigate.  However, then the river level between Knostrop and Leeds Lock suddenly increased after the last recorded passage at Knostrop.  In about 30 minutes the river level increased by 200mm.  It appears the craft was travelling towards Leeds and during the journey the large storm discharge culverts, which has been in place for many years, which flow into the river just below Leeds weir started to discharge a flood from the drainage in North Leeds.  We have no way to predict these occasional large sudden inflows from the storm discharge below Leeds weir; as far as we can tell our water level warning systems (SCADA) worked correctly.

 If I can give you a brief explanation of the weirs operation; The weirs remain up and replicate the previous navigation weirs, unless being tested, up to the point where a large flood event is developing. Then Leeds City Council drop their weir crests to lower the water level through Leeds and down as far as Knostrop lock.  This provides extra flood storage and an increased depth of flow at the weirs so the storm event can pass through Leeds without going over flood walls in a significant flood event.    At the point when the weirs are dropped the river will already be high into red and all the locks will have gone into warning mode. It is not the case that the weirs now go up and down all the time to keep river levels near normal, whilst the flow increases.   I understand that it takes Leeds City Council two hours to slowly drop the weir crests, to avoid a large surge of water flowing downstream.

 Please note that the traffic light at Knostrop lock only shows green if it a Lock Keeper is present. With the lock in user operation, it will show amber and allow craft to pen themselves through. Our SCADA team confirm the lock was in user operation at the time of the reported incident. The traffic light will flash red when the upstream level gets too high, however it can't predict when this will happen, it only gives information based on the current level. The customer who reported the incident we believe must therefore be referring to the water level gauge board being in the green section.

 We can confirm that the new Leeds flood alleviation weirs have not yet been operated, except for testing and will not do so until very high water levels. Up to that point they provide a similar length and height to the original weirs.

The Leeds Flood Alleviation Scheme is led by Leeds City Council in partnership with the Environment Agency and the following is a link to their website which you may find of interest http://www.leeds.gov.uk/residents/Pages/FloodAlleviationScheme.aspx

This is total BS   The water levels have now nothing to do with the flow of water and as shown in my photos the Knostrop weir was lowered for the flood conditions, the water level was lower than normal and well in the green but the flow of water was higher than normal.  Lock was showing amber for normal use.

[Nick D]

As the OP and the person who reported this to the CaRT at the time, I accept that this gives an explanation of what happened. However, the reason for me reporting this is so that it doesn't happen to anyone else in the future.  This reply doesn't address that point and gives no indication of how it could be avoided through extra warnings etc.  What is does say is that the lock indicator can be on green at Knostrop yet it could still be unsafe to travel further upstream.  How can boaters be sure? Unfortunately, this doesn't help.

[Mike Todd]

I think that this is a general situation that will always be true at some times. That is, whilst it may be safe to pass through a particular lock this is no way guarantees that locks elsewhere on the same river navigation will also be safe. As indicated in the CaRT reply, navigations - both canals and rivers - have complex flows in and out and not just a simple pass through down the flow of the stream. For the most part, these additions and subtractions are relatively small in comparison with the overall river capacity but clearly there are exceptions.

There is an important principle here - are CaRT responsible for ensuring that every boater is at all times made aware of the safety of navigation conditions? Whilst we all like to think that we are simultaneously free of a nanny sate but also that 'someone' has a responsibility to prevent us from getting into trouble, this is clearly never really achievable. 

Every master has a duty, to themselves, others on board and others who may be affected (including rescuers) to asses every situation and mitigate the risks. Equally, there is a duty to be sure that a specific journey is within the crew's capability to handle should things go outside the normal operating envelope. In other words, not only must we be confident that we can navigate in the conditions we believe to be present but also we need to know what to do if there is unanticipated difficulty.

For the most part, river navigations are no more complicated than many a canal and can be especially picturesque, they can also have their own idiosyncrasies and I ever venture on one without some measure of trepidation.

For example, earlier this year we traveled upstream from the Huddersfield Broad shortly after the flood gates had be re-opened after a brief closure (mid summer is no guarantee that flood will not happen!) We had to be aware of what we were heading up to and that we could cope in the event that there was a sudden return to flood gate closure whilst we were in transit. (Kirklees Lock has a good landing but an exit from the river into the lock that would not be easy in rapid waters. Also, the lock landing does not have any risers)

Had things turned difficult I was well aware that, just because the flood lock at Cooper Bridge Cut End had been opened, I would not be able to claim against CaRT for giving me bad advice.

[Robbo]

Aire & Calder Navigation Main Line
Starts At: River Weir 2, Knostrop
Ends At: Bridge 2, Crown Point

Saturday 11 November 2017 08:00 until Friday 17 November 2017 17:00

Type: Advice 
Reason: Information

---

 

Original message:

 

The Leeds Flood Alleviation scheme contractor BAM Nuttall are proposing to undertake some additional testing to the weir at Knostrop commencing Saturday 11th November.

This is likely to take up to one week, during which time there may be increased flows as they will be keeping the weir level fixed at a level which is mid-range for the section between Knostrop and Crown Point.  Although these flows could be slightly higher than the norm, dependent upon rain fall and river levels, they will however be within the safe operating parameters.

If there is significant rainfall then BAM Nuttall will restore normal weir levels and allow their works to be flooded out whilst maintaining the standard river conditions.

 

Guessing they were testing before as well, but when the river was in flood conditions looking like it was safe for us to travel due to the dropped level.   As you don't get a sense of flow at knostrop as the river is fairly wide compared to the pinch points near Leeds.