What river comes up quickest?

Inland paddling
Post Reply
User avatar
banzer
Posts: 3292
Joined: Thu May 05, 2005 11:37 pm
Location: Harrogate, Yorkshire
Has thanked: 3 times
Been thanked: 3 times

What river comes up quickest?

Post by banzer » Mon Jul 16, 2018 9:02 pm

Seeing as everything is dry and dog-low...

... what rivers in the UK comes up the quickest, from dead low, to paddleable, in the shortest time? Let's assume there's a massive cloudburst covering the drainage basin for a few hours in summer.

... I would say the Allt a' Chorrainn would be up in couple of hours. Likewise the Cwn Llan.

Not the bigger rivers like the Orchy / Nevis. I reckon the Orchy would take a couple of days because it's loch-fed. The Nevis a few hours. The Swale, several hours. The Upper Dart most of a day? The Duddon is fairly fast, a few hours for that.

In the words of Mitchell and Webb, tell us your 'reckons'...
A. Boater wrote:It's all Pierre's fault
www.neviscanoes.co.uk

jmmoxon
Posts: 5724
Joined: Sat Sep 14, 2002 12:12 pm
Location: Sometimes Sunny Somerset
Has thanked: 3 times
Been thanked: 33 times
Contact:

Re: What river comes up quickest?

Post by jmmoxon » Mon Jul 16, 2018 10:21 pm

A better question may be which needs the least rain - Upper Dart requires 20mm most summers...

Mike
http://kayakworldguide.forums-free.com Links to websites with info on white water, touring, sea & surf.

Yew
Posts: 482
Joined: Wed Jul 20, 2011 8:26 pm
Has thanked: 1 time
Been thanked: 4 times

Re: What river comes up quickest?

Post by Yew » Tue Jul 17, 2018 10:05 am

I feel that the Aberglaslyn comes up fairly quickly.

User avatar
Jim
Posts: 13858
Joined: Sun Apr 21, 2002 2:14 pm
Location: Dumbarton
Has thanked: 7 times
Been thanked: 36 times

Re: What river comes up quickest?

Post by Jim » Tue Jul 17, 2018 12:34 pm

I have seen the Nevis hydrograph with 3 peaks and 2 troughs in 24 hours, the troughs were too low to paddle, the peaks too high to paddle, it changes quickly!

I have also seen Etive tribs come up in the time it took to go and check the Coe first and come back... and still got the Coe in afterwards. (Summer rain)

Just have to be in the right place when it is raining!

User avatar
davebrads
Posts: 1809
Joined: Sun Feb 24, 2002 11:42 pm
Has thanked: 2 times
Been thanked: 4 times

Re: What river comes up quickest?

Post by davebrads » Tue Jul 17, 2018 2:49 pm

It's got to be something short yet with sufficient catchment to make a paddleable river, and also where water runs off very quickly. We did the Fassfern last year after not too serious rainfall and were astonished how quickly the level changed. I reckon you would not need much more than an hour of good steady rainfall to bring it into condition from dog low. But there are loads of little rivers like this around the country, it would be very difficult to measure which is the quickest.

The Duddon is a good call for a bigger river. Years ago we arrived at the Duddon bridge to find the river was about 6 inches below the recommended minimum, but it was drizzling so we decided to give it a go doing both the upper and lower sections. We had a blast, Wallowbarrow Gorge was bank full and when we arrived back at Duddon bridge the river was within a few inches of flooding the road.
it's not a playboat, it's a river runner

User avatar
DaveBland
Posts: 3657
Joined: Mon Jul 19, 2010 10:01 pm
Location: Calgary Canada
Has thanked: 4 times
Been thanked: 12 times

Re: What river comes up quickest?

Post by DaveBland » Tue Jul 17, 2018 5:17 pm

I'm guessing the Duddon too.
Up and down insanely fast.
dave

Slime
Posts: 569
Joined: Thu Feb 07, 2002 6:28 pm
Been thanked: 2 times

Re: What river comes up quickest?

Post by Slime » Tue Jul 17, 2018 5:50 pm

My vote would be for the Upper Derwent which drains Borrowdale and is supposedly the wettest place in England. It's usually up and down within a few hours so unless you live locally you are unlikely to get to paddle it - which is a shame as its a beautiful run. We try to time it so we are getting on just as it stops raining and then it often drops 10cm whilst we are paddling it!

Dr Robin
Posts: 735
Joined: Thu May 13, 2004 2:03 pm
Been thanked: 3 times
Contact:

Re: What river comes up quickest?

Post by Dr Robin » Tue Jul 17, 2018 5:55 pm

I'll take this in a different direction: the Findhorn.

One morning I found the Findhorn dog low: I judged that I could barely squeeze through Randolph's leap. Since I had made the effort to drive there I decided to paddle anyway. I placed my boat a foot above the water surface and started to get in. To my confusion my boat started floating away before I was ready, and I hurriedly finished putting my deck on. The river rose before my eyes and large trees started floating towards me. I got back out and inspected Randolph's leap again: the river had risen 3 metres, and now the rock at the entrance to Randolph's leap was disappearing. The river had gone from dog low to disconcertingly high in seconds.

But probably I'm not answering the question Banzer asked. I think he means: which river responds quickest after rain starts falling? That's certainly not the Findhorn.

User avatar
banzer
Posts: 3292
Joined: Thu May 05, 2005 11:37 pm
Location: Harrogate, Yorkshire
Has thanked: 3 times
Been thanked: 3 times

Re: What river comes up quickest?

Post by banzer » Tue Jul 17, 2018 8:43 pm

That's an interesting, and disconcerting, story Robin. IT's good job it was you and not a uni freshers trip!

Did you find out the cause? Rains upstream all funnelling together? I can't think of any particular hydro dams in the catchment..?
A. Boater wrote:It's all Pierre's fault
www.neviscanoes.co.uk

User avatar
DaveBland
Posts: 3657
Joined: Mon Jul 19, 2010 10:01 pm
Location: Calgary Canada
Has thanked: 4 times
Been thanked: 12 times

Re: What river comes up quickest?

Post by DaveBland » Tue Jul 17, 2018 8:55 pm

If we are into stories...

Me n 'dkel' off of 'ere went to the Duddon looking for some action. It was raining hard and at the takeout was looking like a paddlable level. Only having one vehicle, we walked the shuttle and popped ourselves on the river. It had come up to the level of the stepping stones cable in the time it took us to walk back up and blast down.

By the time we had sorted out the carnage caused by said water level cable and driven back to the bridge downstream, there was about 18 inches of clearance under the arches, causing a bit of a detour.
dave

paddletastic2
Posts: 574
Joined: Tue Aug 20, 2002 1:30 pm
Location: Coventry
Been thanked: 1 time
Contact:

Re: What river comes up quickest?

Post by paddletastic2 » Tue Jul 17, 2018 8:57 pm

Findhorn comes up rather quick!
Image

Dr Robin
Posts: 735
Joined: Thu May 13, 2004 2:03 pm
Been thanked: 3 times
Contact:

Re: What river comes up quickest?

Post by Dr Robin » Tue Jul 17, 2018 10:22 pm

I cannot explain the geography of the effect but the graph above is quite typical, in my experience. In fact, the rising edge can be even sharper than that. As far as I know it is completely natural.

User avatar
Jim
Posts: 13858
Joined: Sun Apr 21, 2002 2:14 pm
Location: Dumbarton
Has thanked: 7 times
Been thanked: 36 times

Re: What river comes up quickest?

Post by Jim » Wed Jul 18, 2018 11:28 am

The Findhorn gauge seems to be near the A9, where the catchment is pretty steep and there seem to be lots of small tribs close together, quite different in character to the normal WW sections lower down.

Heavy rain is often concentrated, so only 1 or 2 stream in a catchment tend to flash flood with the effect diminishing downstream, upper Findhorn catchment is quite compact so maybe all the tribs flash flood simultaneously?

User avatar
chicklechives
Posts: 316
Joined: Wed Feb 25, 2004 10:34 am
Location: Lancy-shire

Re: What river comes up quickest?

Post by chicklechives » Wed Jul 18, 2018 3:31 pm

Agree with Findhorn, similar experience throwing kit up the cliffs and scrambling after it as it rose 3m in 5 mins at Randolf's.
Also similar on the Ure at a slalom at West Tanfield. From div 4 course to all gates being garotting hazard in 5 mins. Strangely both on perfectly dry days with rain overnight.

User avatar
banzer
Posts: 3292
Joined: Thu May 05, 2005 11:37 pm
Location: Harrogate, Yorkshire
Has thanked: 3 times
Been thanked: 3 times

Re: What river comes up quickest?

Post by banzer » Wed Jul 18, 2018 4:13 pm

I guess at Randolph's it all backs up in the big eddy before that tiny constriction.... probably wouldn't be nearly so noticeable 1km upstream.
A. Boater wrote:It's all Pierre's fault
www.neviscanoes.co.uk

stonercanoe
Posts: 150
Joined: Thu May 26, 2011 4:26 pm
Been thanked: 2 times

Re: What river comes up quickest?

Post by stonercanoe » Wed Jul 18, 2018 6:44 pm

Mellte, it's name in Welsh means lightening, referring to how quickly it rises.
Jason

User avatar
Jim
Posts: 13858
Joined: Sun Apr 21, 2002 2:14 pm
Location: Dumbarton
Has thanked: 7 times
Been thanked: 36 times

Re: What river comes up quickest?

Post by Jim » Thu Jul 19, 2018 11:27 pm

banzer wrote:
Wed Jul 18, 2018 4:13 pm
I guess at Randolph's it all backs up in the big eddy before that tiny constriction.... probably wouldn't be nearly so noticeable 1km upstream.
That was my first thought, then I realised the gauge is by the A9 and it clearly rises fast there too!

User avatar
Adrian Cooper
Posts: 9711
Joined: Thu Apr 25, 2002 2:26 pm
Location: Buckinghamshire
Has thanked: 1 time
Been thanked: 12 times

Re: What river comes up quickest?

Post by Adrian Cooper » Fri Jul 20, 2018 10:45 am

The Findhorn has form on flash flooding with the Muckle Spate of 1829, the water level almost up to the top of the arch at Dulcie Bridge (that's absolutely huge for those who do not know the area). It caused massive devastation.

User avatar
banzer
Posts: 3292
Joined: Thu May 05, 2005 11:37 pm
Location: Harrogate, Yorkshire
Has thanked: 3 times
Been thanked: 3 times

Re: What river comes up quickest?

Post by banzer » Mon Jul 30, 2018 9:48 am

FYI re the Swale......

Been very dry but a few showers lately. Forecast for the Swale region was a bit of rain overnight, not much, then 11mm between 6am and midday, tailing off in the afternoon.

Sunday morning, the online gauge at Park Bridge was at 0.32 at 6:30am (I bit higher than I had expected actually)

We drove there and arrived at 10am, still pretty low, about 0.35. It was raining. Sat it out / had a cuppa / went for a walk; rising all day. Started doing a couple of laps on Wainwath. Finally got to a decent level (0.75) at about 1:30pm. Happy days. Peaked at about 0.8, then started to fall later in the afternoon when rain had stopped.

So....

A forecast (on yr.no) of 11mm over a 6 hr period when there's a little bit of baseflow appears to be enough to bring the Swale up, even if it's been pretty bone dry. And it takes about 6 hours of rain, not mega heavy, but fairly constant. There you go. :)
A. Boater wrote:It's all Pierre's fault
www.neviscanoes.co.uk

SPL
Posts: 273
Joined: Tue Sep 20, 2005 9:23 pm
Been thanked: 1 time

Re: What river comes up quickest?

Post by SPL » Mon Jul 30, 2018 3:18 pm

Erme in Devon, up in a shower down in the hour.

Post Reply

Return to “Whitewater and Touring”