tweedsider
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Quietness is best
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Post by tweedsider on Sept 21, 2008 14:56:34 GMT
I dont know about other parts of the country but two weeks ago the Borders had one of the most extended periods of heavy rainfall for mony a year. Extended rainfall means high rivers, in this instance bank bursting high rivers, a newly sown rape field near where I fish resembles a gravel strand complete with stranded trees and sand dunes. This some 10ft above river level I may add. On the rever bed itself there is evidence of clean sandstone slabs, either turned over by the force of spate or scoured clean by the same agency. This must not be good when we consider the amount of juvenile salmon fare is found below riverbed stones. Aquatic insect eggs, larvae in all stages of development must have been swept away. Short term it must have done considerable damage, long term Nature has , if allowed the knack of making a recovery over an extended period.One heartening thing observed since this recent spate is the amount of, "pinhead" minnows in the shallows. How they managed to survive is almost beyond comprehension. So far I have seen no evidence of fish of any description washed ashore, what has been the experience of other Forum members following the above conditions.
Tweedsider
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Speyducer
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Post by Speyducer on Sept 21, 2008 19:13:46 GMT
However, is there a 'plus' side to the rather higher rainfall through August with the repeated high water levels & spates of this year ??
Will there be more 'escapement' of fish into the spawning streams and away from the casting frenzy of the late summer/backend fishers??
Time will tell, I suppose...
Mike
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Post by G Ritchie on Sept 21, 2008 19:29:41 GMT
These large spates have been much more frequent on the Deveron in recent years due to more efficient drainage by agriculture and forestry industries, also due to more intense periods of rain (the effects of global warming?). While these large spates may result in the loss of some salmon parr, those that remain will have less competition and so survival rates to the next stage should be higher, this will offset some of the initial losses. I have certainly not noticed any firm evidence of lower salmon runs a couple of years after one of these very large flood events.
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Tyne Andrew
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April Spring Salmon 2010 - Lower Pitchroy, River Spey
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Post by Tyne Andrew on Sept 21, 2008 19:35:22 GMT
After the biblical sized spate on the Tyne in early September, i was out on the lower river on Saturday and was very proud of the huge shoal of small 2008 fry that were in the shallows!
They obviously find a way - very impressive
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Post by salmonking on Sept 21, 2008 20:02:23 GMT
;D,You lot are gonna call me soft here,but the other night i was fishing ,as i walked by a small puddle i noticed a slight movement on closer inspection i noticed a shoal of sticklebacks ,spent the next half hour carefully catching and returning them to the river...got every one 34 of them.
There has been some dramatic changes to the beat i fish after the spates with new Ly's created and some graveled up and not so good any more....i like a change though,life would become boring without change,i can't see the spates we've had doing any harm to the river or the stocks whatsoever...bring on the spates.
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conwyrod
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Autumn on the Conwy
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Post by conwyrod on Sept 21, 2008 20:29:49 GMT
on closer inspection i noticed a shoal of sticklebacks ,spent the next half hour carefully catching and returning them to the river...got every one 34 of them. 69 + 34= 103 ;D
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Post by salmonking on Sept 21, 2008 20:33:40 GMT
;D...do they coun't..! very good John.
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Post by sinkingtip on Sept 21, 2008 20:42:11 GMT
34 !! ?? - Nice on Col, and not even tempted to chap one for the pot ? ...... put it there mate. That must surely be 'up there' with Graham Ritchie's most recent 'red letter' day. Next time they are selling flags for "Stickleback Rescue" I, for one, shall contribute. In admiration. STip
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Speyducer
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Release to spawn another day
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Post by Speyducer on Sept 21, 2008 20:55:57 GMT
;D...do they coun't..! very good John. Only if they have been photographed, or witnessed by an angler of unquestionable honesty (& O level maths!)! They will still count even if you haven't done a length-girth measurement on each individual, as this would keep you off the river too long ;D ;D Mike
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Post by sinkingtip on Sept 21, 2008 22:40:26 GMT
Back to topic. I think we can all assume that extreme spates will take its toll on the aquatic 'health' of a river at certain times of the year namely, the spawning period. On the Tay you can very often find eggs washed up on the paths and flood-banks after the water has receded. Also, a wee black cocker I used to own had an uncanny knack of finding (and rolling about in) rotten fish carcases quite some distances away. As the owner of the Dalguise fishings will unhappily testify, they can cause expensive, repeated and huge physical damage to a beat - spates, not the cocker although she was a bugger for digging out holes. Part of the debate might be whether or not beats should build 'flood-banks' or take any form of preventative measures - "as it's just sending the problem downstream" - a phrase now shiny with use. Is it not better to just let nature do its 'thing' ? - no consolation I know if you happen to be a householder living in a low lying area. Spates ? - cant live with 'em - cant live without 'em ? STip
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tweedsider
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Post by tweedsider on Sept 22, 2008 18:24:07 GMT
Hello Stip you have hit the nail right on the head regarding the purpose of my post, which was not merely about the change in river bed configeration , but the damage to the food chain this would cause. Perhaps I am at fault for not mentioning in the original post that it would have been many degrees worse, should the high water levels have occured after the main spawning time. It is obvious that with excessive river levels thousands of tons of gravel have been on the move, bad news indeed if that were gravel from spawning redds. Yes we need spates to keep the river refreshed and allow fresh runs of fish to enter, but prefered to remain between 3 and 6 ft in height rather than a thundering maelstrom. Tweedsider
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Post by G Ritchie on Sept 24, 2008 19:55:21 GMT
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Post by sinkingtip on Sept 25, 2008 7:18:17 GMT
Quote : “Reconnection of rivers to floodplains is not only good for fish and river life, but can also play a part in reducing flood risk. By allowing high flows from rivers to spill safely into what is a natural part of the river channel, it can help reduce the potential risk of river banks bursting further up stream.”
Interesting article Graham. Especially the rationale behind allowing rivers (beats) to "reconnect" with their flood plains. regards STip
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conwyrod
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Autumn on the Conwy
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Post by conwyrod on Sept 26, 2008 20:10:38 GMT
Interesting article Graham, and the conclusions make a lot of sense.
The EA are negotiating with farmers in the Conwy valley to remove some flood banks. By allowing some fields to flood, this will reducing flooding of a village further downstream. Hopefully this will benefit the ecology of the river as well.
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tweedsider
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Post by tweedsider on Sept 27, 2008 16:12:56 GMT
Almost anywhere in Britain John you will see the folly of floob embankments, virtually tying down the safety valve which Nature has provided on all rivers.
Tweedsider
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Speyducer
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Post by Speyducer on Sept 27, 2008 17:10:55 GMT
River flood defences by building dykes & walls are only as good as the weakest or lowest point in the system, and at that point, the water will break through, and flood the surrounding area. Managing unusually high rainfall, with the sweeping of large amounts of water off the catchment area and into the river basins, and therefore downstream flooding, may be best by allowing some land to flood at such times, therefore protecting other more vital structures from such floods (power stations, sewage plants, hospitals, factories, houses, roads, rail, etc...). Whilst it is not anticipated that current infrastructures would be moved off such allowable flood plains, indeed, it is also unlikely that such land development will cease on such areas in the future, the Dutch, who have been managing flooding from the sea since their lands were first inhabited, and therefore know a thing or two about such flood management, have designs for buildings which take into account of anticipated rising waters. www.csmonitor.com/2005/1026/p13s02-lihc.html Although such developments may be considered expensive, these solutions, or others with similar innovations, may work out somewhat cheaper in the longer run than repairing all the flood damaged properties on a regular basis, and would give such inhabitants of these areas in such structures a whole lot of confidence in their own security. Mike
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tweedsider
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Post by tweedsider on Sept 27, 2008 19:20:22 GMT
Mike, I am sure that within recent years a whole system of flood banks was built near Peebles to protect a golf course located on what should have been the spill over or flood plain. That was one of the places that came to mind.
tweedsider
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Speyducer
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Post by Speyducer on Sept 27, 2008 20:28:10 GMT
Is the golf course private or publically (council) owned??
Mike
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tweedsider
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Post by tweedsider on Sept 27, 2008 20:39:36 GMT
I think it 's a private affair and incorporated a pretty large housing development if my memory serves correct, mind its a while since I 've been in that airth but I know there are a lot of flood dykes there now which were not present years ago. tweedsider
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db
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Post by db on Sept 27, 2008 21:01:28 GMT
I think it 's a private affair and incorporated a pretty large housing development if my memory serves correct, mind its a while since I 've been in that airth but I know there are a lot of flood dykes there now which were not present years ago. tweedsider Aye, that'll be Cardrona with the golf course and big fancy 'scheme'. Just to top it all they built a big white hotel in an area of outstanding beauty . King of Salmon, the stickleback saviour, was on there last year. I think we overestimate the damage a spate can do - fair enough, they can rip banks apart on bends and scour out holes, but i think where fish lay down redds the water is usually of uniform flow. Even in a big spate, where fish redds will be, the water is fast and smooth but not turbulent.
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