Thames river levels

[Aquafan]

Good morning all,
Despite low rainfall this winter the river has been on red boards for most of it as it is now but why, it wasn’t like this a few years back?
Have the lock keepers changed the criteria they use to put red boards out … I don’t think so.
Talking to the owner of a dredging company he agreed that the slightest rainfall means the river level goes up, he suggested it might be that the water table hasn’t returned to normal levels after last winter?
Is it the lack of dredging in recent years reducing the river’s capacity therefore taking longer to get rid of the water?
Whatever it is it doesn’t bode well for the future in terms of flooding and allowing us to use our boats.

 

[thamesS23]

well I have been boating on the thames for about 8 years now, but I wouldn't say that this winter is any different in terms of red boards than any of those other years. (infact it is alot better this year compared to last year)
"Whatever it is it doesn’t bode well for the future in terms of flooding and allowing us to use our boats." - so I would disagree with that comment and say that I am sure this year will be as good as all the others in allowing us to use our boats.

 

[Chris_d]

Well with over 40 years of observing the river I would say it is fairly normal for this time of year and yes last years wet winter has had a effect.
But the river level has been fairly constant, remember red boards are triggered by flow not level.

 

[Wavey]

Living where we do with just a hundred yards or so of meadows separating us from the River Wey we've noticed that although we had a great summer last year the water table is still very high after the previous winters enormous rainfall. It doesn't take much for the fields around us to start flooding as the ground is still saturated. Where else can it go but drain into the rivers.

 

[mlines]

It seems to me that its not been too bad for red boards this year. There has certainly been plenty of occasions where it would have been possible to get out on the water.

 

[Actionmat]

I agree with the OP. We've had a bit of rain(not a mini monsoon like last year)and the boards are back. I'd use my boat every weekend if it wasn't for the fast flow. I know I'm paying for the privilege of floating and not cruising but I don't feel like I'm getting much for my money so far this year.
When we go away for 2 weeks in the summer, I'm concerned that a bit of rain will cause us problems on the return leg.

How much dredging was done on the Thames last year? The only thing I saw removed down my end was shopping trolleys.

 

[TrueBlue]

Shock Horror!
I've just seen a post on another forum that The Severn is closed - on red boards. So they've had a lot of rain (not surprising - if you watch the weather forecasts)

I don't think many folks on here realise that the Thames catchment area is huge will loadsa' tributaries feeding it. It may be dry in sunny Surrey but well to the west it's 'orrid.

The winter's / off season is always pants for boating. Every year we say we'll do some out of season boating but it just doesn't happen. Either the river's on Reds or essential lock repairs mean you can't go 'anywhere'

 

[Chris_d]

I agree with the OP. We've had a bit of rain(not a mini monsoon like last year)and the boards are back. I'd use my boat every weekend if it wasn't for the fast flow. I know I'm paying for the privilege of floating and not cruising but I don't feel like I'm getting much for my money so far this year.
When we go away for 2 weeks in the summer, I'm concerned that a bit of rain will cause us problems on the return leg.

How much dredging was done on the Thames last year? The only thing I saw removed down my end was shopping trolleys.

I share your frustration but if we were paying the EA to control rainfall and guarantee the river was navigable I think it would cost considerably more

 

[Aquafan]

I was under the impression the boards were triggered by level and not flow

 

[Chris_d]

I was under the impression the boards were triggered by level and not flow

Have a look here http://riverconditions.environment-agency.gov.uk/
No where does it mention levels its all about flow, a Red board means a dangerous stream not a dangerous level.
Lockies determine which board from the number of weir gates they have open, when they reach maximum flow i.e all gates wide open and more water flows into the river the level will start to rise.
The river is currently at normal levels in most places except for the abnormal flow.

 

[Aquafan]

Agreed the number of weir gates open determine whether red/yellow board are out but its the level of water that determines the number of gates open/closed not flow

 

[Actionmat]

I share your frustration but if we were paying the EA to control rainfall and guarantee the river was navigable I think it would cost considerably more

I was under the impression that the Environment Agency(apart from controlling the river)also concentrated on healing the planet, so controlling rainfall(or at least ensuring that the guttering is clear enough to take the extra flow)doesn't sound unreasonable to me

 

[CJL]

High groundwater levels are still very much with us so any rainfall won't infiltrate the ground easily so it will flow much faster into the rivers making a much "flashier" catchment. Check out this website for summary ground water levels = www.bgs.ac.uk/research/groundwater/datainfo/levels/levels_news.html

"Flashy" catchment = high flows in rivers regardless of what anybody does!

CJL

 

[Cashbuyer]

It hasn't been half as bad this winter as the past two years. And far fewer red boards. We've been out for a day trip nearly every weekend so far this winter and only curtailed for overnights by lock closures.

Stuck at Harleyford 2012/13 with flooding and both Hurley and a Temple locks closed. That was annoying...

 

[Reptile Smile]

Hi all,

I'm not so much looking for clairvoyancy here, as hoping to make the most of your educated guesses and experience.

Being a teacher, I'm free for easter holidays starting the two weeks from 22nd March. I'm aiming to bring a boat along the Thames then, and assumed that easter was probably quite an important time for the hire industry, etc, and hopefully would be open.

That's 4 weeks away now, and I'm starting to get slightly twitchy. What are the chances of the river being 'open' in a month's time?

 

[boatone]

Being a teacher, I'm free for easter holidays starting the two weeks from 22nd March. I'm aiming to bring a boat along the Thames then, and assumed that easter was probably quite an important time for the hire industry, etc, and hopefully would be open.
That's 4 weeks away now, and I'm starting to get slightly twitchy. What are the chances of the river being 'open' in a month's time?

The EA have told us that all outstanding lock works will be completed by mid March and that the river will, in that sense, be "open" well before the Easter holidays start. My guess - and it is a guess - is that we will see flow rates back to more normal levels well before then assuming that this Met Office 6-30 days forecast proves to be reasonably accurate:

Outlook for the UK over the next 6-30 days
UK Outlook for Tuesday 3 Mar 2015 to Thursday 12 Mar 2015:
Conditions will be generally unsettled through the start of March with spells of cold, showery conditions interspersed with milder wetter periods. Northwestern parts will see the most frequent rainfall, and perhaps some further snowfall at times. It will also often be windy with gales, occasionally severe, across northwestern coasts and hills. Between these unsettled spells, drier and sunnier periods are likely, most prolonged across southern parts. There is an increasing signal that more prolonged settled conditions are likely to become established into the second week of March, with high pressure developing across much of the UK. The temperatures will vary with the passage of the weather systems, but will generally be near, or just below, normal for the time of year.
UK Outlook for Friday 13 Mar 2015 to Friday 27 Mar 2015:
There remains an increasing signal for higher pressure to develop at times across much of the UK. This would bring generally more settled conditions with many places dry and often sunny. Temperatures are rather uncertain, but maybe below average at times and cold overnight. This will lead to a risk of overnight frost, along with some local mist or fog patches, although these should quickly clear beneath the early spring sunshine. Whilst some cloudier conditions, along with spells of rain and showers are possible at times, the risk of any prolonged wet and windy conditions will be fairly low.
Updated at: 1100 on Thu 26 Feb 2015

I am inclined to believe that residual water table levels after last years extraordinary conditions leave the river very vulnerable to rapid changes with relatively low rainfall but so much depends on where it falls. We have been experiencing swathes of rain travelling west to east along the whole length of the river and the cumulative effect as the water travels downriver is, therefore, considerable.
For most of us experienced river users navigating under yellow board conditions is not much of a problem but conditions can change very quickly. A few years back Yellows started appearing as I passed through Reading and I was forced to take refuge at Windsor for several days as Red boards overtook me!

 

[Chris_d]

I'd agree with B1 above the signs are good that it will be ok, unless we get more than one days continuous rain in a row the river should at least be navigable even if there are is a strong "flow"

 

[mlines]

Well I have a report that the "tide has gone out" between Shepperton Lock and Sunbury lock. Some boats moored close to the bank are touching the bottom.

 

[mlines]

Gauge seems to agree...

http://www.paddlebubble.com/river_gauges/v/1826/walton/thames

 

[Actionmat]

I am inclined to believe that residual water table levels after last years extraordinary conditions leave the river very vulnerable to rapid changes with relatively low rainfall but so much depends on where it falls. We have been experiencing swathes of rain travelling west to east along the whole length of the river and the cumulative effect as the water travels downriver is, therefore, considerable.
For most of us experienced river users navigating under yellow board conditions is not much of a problem but conditions can change very quickly.

Thanks. That explains the fluctuation nicely.

I have no problem navigating when the river's running fast, it's getting on to my home mooring that's the problem. Turning 90 degrees and aiming between two piles with a fast flow pushing me sideways downstream is challenging to say the least. Fortunately for me, on the one occasion I was caught out, Teddington Lock were very understanding and accommodating until the river calmed down.