EA Levels Calibration Topic

[Jim Pullen]

EDIT: A new England and Wales calibrated river levels site is now available: Rainchasers
This has many calibrated gauges for the northeast. If you think the calibrations are inaccurate, or have info on gauges not on there yet, please post below or contact them directly.

Direct link to our region:
http://www.environment-agency.gov.uk/homeandleisure/floods/riverlevels/120498.aspx

To simplify things I'm going to limit the number of gauges to look at and stick to upland rivers, so in list form we have:

Till Area

Coldgate Mill (North Middleton) for Wooler Water
Wooler for Wooler Water

Northumbeland Rivers

Shilmoor for Usway Burn
Alwinton Bridge for the Coquet
Rothbury for the Coquet
Morwick for the Coquet
Nunnykirk for the Font
Hartburn for the Hartburn
Middleton Bridge for Wansbeck
Mitford for Wansbeck
Stamfordham for the Pont
Heugh Mill for the Pont
Callerton Lane for the Pont

Tyne

Kielder Burn for Kielder Burn
Otterburn for the Rede
Otterburn Mill for the Rede
Rede Bridge for the Rede
Bellingham for the North Tyne
Reaverhill (Barrasford) for the North Tyne
Alston for the South Tyne
Featherstone (Rowfoot) for the South Tyne
Haydon Bridge for the South Tyne
Allen Mill Bridge for the East Allen

Wear

Wearhead for Killhope Burn
Eastgate for Rookhope Burn
Stanhope for the Wear
Bedburn for Bedburn Beck
Witton Park for the Wear

Tees

Moorhouse for Trout Beck
Harwood for Harwood Beck
Middleton for Tees
Barnard Castle for Tees
Broken Scar for Tees
Rutherford Bridge for the Greta
South Park for the Skerne
Foxton Bridge for the Leven

Swale, Ure, Nidd and Upper Ouse

Park Bridge for the Swale
Reeth for Arkle Beck
Grinton for the Swale
Richmond for the Swale
Catterick Bridge for the Swale
Low Houses for Snaizeholme Beck
Bainbridge for the Ure
Kilgram for the Ure
Masham for the Ure
Gouthwaite for the Nidd
Pateley Bridge for the Nidd
Birstwith for the Nidd

Derwent

Broadway Foot for the Rye
Ness for the Rye
Howe Bridge for the Rye
Cherry Farm for Hodge Beck
Kirkby Mills for the Dove
Sinnington for the Seven
Normanby for the Seven
Nunnington for the Riccal
Levisham Station for Pickering Beck
Pickering for Pickering Beck
Levisham Mill for Levisham Beck
West Ayton for the Derwent
Low Marshes for the Derwent
Malton for the Derwent

Wharfe and Lower Ouse

Kettlewell for the Wharfe
Grassington for the Wharfe
Addingham for the Wharfe

Aire and Calder

What's useful here????

Don and Rother

Ditto????

I really know nothing about the rivers in the Southern part of our area, and not much about the far North or Yorkshire Moors so any advice welcome. I've highlighted the gauges I think we should focus on in bold, obviously this is open to debate!

[Jim Pullen]

So on Tuesday night it was honking it down around the vicinity of my house in Darlington (guess at 5mm/h for about 3-4hr). As it hadn't rained for weeks I wasn't sure whether this would have any effect on the water levels. Looking at the data for all the Tees/Greta gauges it didn't! Whether this was because it was very localised rain or because the Pennines just drank it all I'm not sure.

However, because these gauges cover a very extensive range for the North East, I can look at what the mighty Skerne was doing here (about 3 miles from my house). This did in fact rise to a level of 0.38m at around 7am on Wednesday. Unfortunately I didn't look at it in the morning, but did have a look around 1830 that evening, by which point the gauge reading had dropped to ~0.3m.

Conclusion: If you ever felt the need to paddle this urban ditch you'd need more than 0.3m on the South Park gauge!

[Poke]

Park Bridge for the Swale
Reeth for Arkle Beck
Grinton for the Swale
Richmond for the Swale
Catterick Bridge for the Swale

Why this choice of gauges for the Swale?
I'd have thought that Park Bridge, and RIchmond would be the key ones, given these are on the two most paddled sections?

[Jim Pullen]

Park Bridge for the Swale
Reeth for Arkle Beck
Grinton for the Swale
Richmond for the Swale
Catterick Bridge for the Swale

Why this choice of gauges for the Swale?
I'd have thought that Park Bridge, and RIchmond would be the key ones, given these are on the two most paddled sections?

My logic was that Grinton was the start of the normal 2/3 section that's paddled (getting out at Richmond). I would have thought the gauge at the start would be better than one at the end?

I'm led to believe that there's a nice park-and-play wave which forms at Catterick Bridge in certain levels. I thought calibrating this would be useful?

[tape34]

.............
I'm led to believe that there's a nice park-and-play wave which forms at Catterick Bridge in certain levels. I thought calibrating this would be useful?

Hi Jim,

I've heard this too but never seen much of a playwave there, at levels when it does get interesting the risk of being swept into bushes down river would put me off using it. Maybe someone else has better info?

I like the idea of building a network of information like this, anything to help get us on rivers at good levels and without driving miles just to go and look.

Is it possible that the EA already has some photographic descriptions hidden away somewhere?

Pete Ball

[geyrfugl]

Would have been useful if that list had actually been a list of links to the individual gauges (then I could have cribbed the html to put on the SOC website - now I'll have to do it myself:)

There's a photo of the Catterick Bridge playwave http://www.geograph.org.uk/photo/1280701 but it was taken more for geograph's purposes than as directly useful for kayakers. It was quite wet, but I've no idea where a gauge might be, so I can't relate that to the info on the net... It looked quite a useful level with not too much hazard from branches downstream on that particular day.

One big problem seems to be that this new site is telling me the "highest level recorded", but doesn't say when records began. There used to be a page giving historical info for the level of the Tees at Barnard Castle, which gave a highest level for each year - I'm sure the highest level there was before the date of the highest level on these new pages, so I suspect they only go back a few years. The highest level ever recorded at Barnard Castle was in the storm that took out the Whorlton bridge, when it was well over the top of the County Bridge in Barnard Castle (13th October 1829). The records on the new site definitely don't go that far back...

I'll try to remember, when taking river level photos from Abbey Bridge (school just finished, so won't be until after the summer) to get the gauge info next day, so I can relate the photos to the level on the graph. I have a definite interest in the Greta gauge at Rutherford Bridge, too. Pity there's no release info for Cow Green - that would be useful for the level of High Force to Low Force, when a release can often mean levels very different from natural run-off...

Andy

[Jim Pullen]

Would have been useful if that list had actually been a list of links to the individual gauges (then I could have cribbed the html to put on the SOC website - now I'll have to do it myself:)

There's only so many hours in the day! Seriously though all these links and stuff will be available once our little summer project is finished...

There's a photo of the Catterick Bridge playwave http://www.geograph.org.uk/photo/1280701 but it was taken more for geograph's purposes than as directly useful for kayakers. It was quite wet, but I've no idea where a gauge might be, so I can't relate that to the info on the net... It looked quite a useful level with not too much hazard from branches downstream on that particular day.

There's a picture in the guide:

It's also in English White Water as a specific playspot.

One big problem seems to be that this new site is telling me the "highest level recorded", but doesn't say when records began.

I think this is different for every gauge. If you look at the info for the Barnard Castle Gauge, you'll see it was constructed in 1966. I've got a feeling I heard/read somewhere that this only works up to bank full and then the readings don't mean much...

Pity there's no release info for Cow Green - that would be useful for the level of High Force to Low Force, when a release can often mean levels very different from natural run-off...

Agreed, the EA were very protective about telling us this when I tried contacting them. However, calibrating the Middleton gauge will give the best indication for the upper. If we also work out how the Harwood gauge affects this then the difference is the Cow Green release plus whatever's coming down Maize Beck.

[geyrfugl]

I've just noticed in the little panel at the top right, a bit that says "site opened" for each gauge. Clearly records don't go back further than that (or, if there are previous records, it will be an older gauge and the numbers not directly comparable). It's not absolutely clear that records for the site go back to the site opening date, but its the obvious assumption.

The pages show the 48 hours before the last reading. It would be useful if you could specify a date in the past and see the records, as that would enable you to pick days when you have river photos, or did a trip, which would make the calibration process that much faster... I wonder if there are any hidden interfaces to the site that will get this...

Meanwhile, I will set up a cron job to download and keep the daily graphs, so at least we will be able to refer back to past data for subsequent seasons (I already download a north Atlantic synoptic chart every six hours and archive these, which has proved useful...)

For the Swale at Grinton, I assume this is the gauge river right immediately downstream of the bridge. The one that is harder to see from anywhere other than actually in a boat on the river, and therefore not the one that we've always used in the past, which is the one on the downstream side of the middle bridge pier. Ho, hum - I expect a bit of research will produce a simple number to add or subtract to get from one to the other (oh, and a conversion from metres to feet...), then the numbers we already know will become useful.

[Jim Pullen]

To add some more links to help out with data processing:

List of gauging stations with GRs

There's also some history in the HiFlows section of the EA's site here.

For Barnard Castle for example: http://www.environment-agency.gov.uk/hiflows/station.aspx?25008

Unfortunately this only shows peak flows and such like.

For the Swale at Grinton, I assume this is the gauge river right immediately downstream of the bridge. The one that is harder to see from anywhere other than actually in a boat on the river, and therefore not the one that we've always used in the past, which is the one on the downstream side of the middle bridge pier. Ho, hum - I expect a bit of research will produce a simple number to add or subtract to get from one to the other (oh, and a conversion from metres to feet...), then the numbers we already know will become useful.

What's more annoying is that we can't yet convert from the figures we knew from the RiverCall service because they gave their readings as above normal summertime flows, but using exactly the same gauges! For instance the BC gauge used to be just runnable above 0.15m and started getting good from 0.30m. Looking at it now I'm guessing you'll need to add ~0.7m onto that figure.

[geyrfugl]

The EA site points you at the Centre for Ecology and Hydrology River Flow Data site for historical data (http://www.ceh.ac.uk/data/nrfa/river_flow_data.html), but this gives flows in cumecs averaged over a full day. I can't find anything that tells you how to translate these figures into levels at the gauge or vice versa. So I can generate descriptions of what the Tees Greta was like to paddle when the Rutherford Weir indicated flows of 4.63 cumecs ("a nice level") and 5.84 cumecs ("six inches higher", faster and more full-on), and what Sleightholme Beck was like when the Greta gauge was at 7.86 cumec (needed more water), but no way to tell what these flows mean in terms of level on the gauge. There's just not quite enough data to be useful - how frustrating !! Also, of course, a flow rate averaged over 24 hours is not necessarily useful for rivers that come up and drop off in a few hours, even if you could translate.

[Jim Pullen]

There are models for translating cumecs into level, eg for the Greta:



...but as you say for 24 hours this is useless!

[geyrfugl]

Ah, useful then. I see these graphs use the gauge numbers from the National River Flow Archive
which also appear on some other sites, which are different from the numbers used in the EA
gauging pages, which, in turn, are different from the id numbers used on the flow graph
images. They do a remarkable job of making the data difficult to relate to each other...

That graph suggests that between 0.6m and 0.7m on the Tees Greta you will have a pleasant
trip with enough water to start from Gilmonby bridge. Above that and it will start to get
fast and furious (and outside my personal experience). Down to 0.4 the river should go starting
at the weir, and below that I'd think it would be a scrape. The peak averaged-over-a-day
flow seems to have been about 54 cumecs - 1.6 ish on the gauge, whilst 25 cumecs
seems to occur about annually (0.9m ?) and is probably getting a bit full for paddling.

I keep seeing this abbreviation QMED - anyone know what that means (Quite Manic
Ending in Destruction ?) I presume it is something like a limit to the range over which the
level on the gauge reliably relates to a flow rate....

Andy

[linda]

Hi

Just a few comments on this for you - I work in hydrology in Newcastle and spend most days playing with this kind of data so I'm happy to help calibrate the new EA data where possible.

QMED is the median flood, this is normally the flow which is expected to occur once every two years and in most natural channels will be approximatly equal to bank full.

In most cases the EA measure the river level and then use the rating curves which you have found to convert this to flow (which is what is then reported). The coefficients underneath the graphs can be used to convert between one and the other relatively simply.

The EA Hi-flows data set only includes occurances when the flow is above some given threshold (specified individually for each gauge). They therefore report either AMAX values - tha annual maximum flow in each year, or POT values - all values over the specified threshold, this would usually be around 3 to 4 values per year. So this data set is only going to include the highest levels.

The national rivers flow archive page includes a more comprehensive data set but as you've already found out this is only the daily average flow. I am currently in the process of figuring out a way to transfer between this and the peak flow for an event as part of my PhD so if I get something to work I'll let you know!

Linda

[Jim Pullen]

Here's a list of the gauges to concentrate on calibrating for the North East with their Grid Refs (I'd put the links up to them, but the EA site is down at the moment!):

Alwinton Bridge for the Coquet NT923056
Bellingham for the North Tyne NY834832
Reaverhill (Barrasford) for the North Tyne NY906732
Alston for the South Tyne NY716465
Featherstone (Rowfoot) for the South Tyne NY672611
Haydon Bridge for the South Tyne NY856647
Allen Mill Bridge for the East Allen NY831566
Wearhead for Killhope Burn NY857396
Eastgate for Rookhope Burn NY952390
Stanhope for the Wear NY983391
Harwood for Harwood Beck NY849309
Middleton for Tees NY950250
Barnard Castle for Tees NZ047166
Rutherford Bridge for the Greta NZ034122
Park Bridge for the Swale NY886015
Grinton for the Swale SE047985
Catterick Bridge for the Swale SE226993
Masham for the Ure SE226812
Kettlewell for the Wharfe SD968722
Grassington for the Wharfe SD998638

[Jim Pullen]

Ok, they're back!

Can someone go and see if anything's paddleable at the moment?! :-)

[G32turbo]

Eh? What are back, the rivers or the data?

I'm still getting messages of system under maintenance from the EA site.

[Jim Pullen]

Eh? What are back, the rivers or the data?

I'm still getting messages of system under maintenance from the EA site.

Yeah, sorry the EA site was running again for all of two hours yesterday before being taken down again.

I'll try not to get excited too quickly next time...

[Jim Pullen]

Back again!

I'll grab some readings now for reference as most of the rivers are currently up.

For the Tees, BC at 1.17m this morning, Middleton at 1.37m, Harwood at 0.70m (above normal range!) so I guess this represents a good flow without Cow Green releasing loads?

Rutherford Bridge for the Greta at 0.89m this morning, also good to go?

Wear: Wearhead at 0.43m, Stanhope 0.82m. Rookhope Burn 0.34m - anyone know if they were running this morning?

South Tyne: Alston 0.67m, Featherstone 0.60m, Haydon Bridge 0.73m (at 15:00). East Allen at 0.36m

Swale at Park Bridge was at 0.81m.

Wharfe: Kettlewell 1.04m, Grassington 0.95m.

Most of these were at 5:30am, some a bit later.

Any use?

[Jim Pullen]

I've just realised that we can compare the last 48hrs data for the Reaverhill gauge with the one on the FishPal site which we already have calibrations for.

So the peak yesterday was 1.06m at around 1500, on FishPal this reading was around 2.2ft. At 0600 today the reading was about 0.75m compared to about 1.2ft.

So using GCSE maths equations for a straight line y-y1 = m(x-x1), we get 0.31=m*1. m=0.31.
Solving y=mx+c we get 1.06=0.31*2.2+c, c=0.38

So the previous calibrations we have are:

Scrape = 1ft8inches= 1.67ft which is therefore equivalent to 0.90m
Sensible Minimum = 2ft7inches = 2.58ft which is equivalent to 1.18m
High = 6ft11inches = 6.92ft which is equivalent to 2.53m

[Jim Pullen]

Looks like some of the rivers were up on Saturday - did anyone get out this weekend? If so what were the levels like?

[Jim Pullen]

I paddled the Wharf from Coniston to Linton and it was at a nice level, with Linton falls at a good runnable level.
This was on Sunday we got to Linton falls around 2pm around 0.3m

[g0229337]

River: Derwent Howsahm wier
Date: 25/9/10
Time: 16:30 - 18:30
Level: 0.78m @ Buttercrambe
Medium level, Small stoper across all of wier, shoot chunky and holding only upside down to exit.

[mole]

Some useful gauges in Aire and Calder are "Fleet Weir (Woodlesford)" which is where the Aire Wave is and "Nutclough (Hebden Bridge)" which is Hebden water. Sorry don't have any calibration data.

Neill