Respect is Due 2 — Heron on the Sowe

Some time ago now I published a graffitti piece of a zander that suddenly appeared upon one of the M6 motorway support columns where it crosses the Coventry Canal. I don't know about you but graffitti is okay in my book only when it captures the imagination, finding the majority little more than a splash of meaningless colour brightening those drab and neglected corners of the world where the sub-culture that creates them likes to hang out.

I don't appreciate the majority of those pieces because I'm not part of their culture and don't understand the underlying thought processes that lead to someone breaking the law, or even risking life and limb, to create something with such a strictly limited audience and appeal but using such advanced technical skills. I can see they take a great deal of effort to make and require a dab hand to be any good, but who cares how dangerously they were achieved if they don't speak to us?

But then along came Banksy and the stencil revolution. Then we had arresting images cleverly placed carrying ironic/sardonic messages that actually did catch everyone's imagination, not least those of canny art dealers who saw the market early, cut them from their proper context and transported them to their galleries...

I thought that the zander was really something because it suggested that whoever created it actually knew something about the fish population of the canal. Well, it took some time before anything else remotely pertinent to its context and therefore appealing to the eye turned up, but then this piece appeared on the side wall of the weir on the River Sowe in Longford Park one morning last week ~

Clever I think, and if it weren't for the fact that herons actually do visit this river would be ironic...

...but I wonder how difficult it would be to prise those planks off the wall..?

...and if RJL the artist responsible was fully aware that someone might want to take irony a stage further, take them away and stick them back up on theirs...?

Build It and They Will Come — A Roach by Any Other Name (Pt6)

There's a countrywide movement of enthusiastic amateur involvement in river rehabilitation. Streams all over Britain are in process of an overhaul, their habitat shortcomings rectified and potential maximised not only for the health of river environments, but also for angling too. And that is all to the good.

Much of this work consists of really heavy duty and to my way of thinking, heavy-handed manipulation of the watercourse concerned. A project is considered, cleared by someone high up in the chain of command and then implemented by a gang of hard working volunteers dressed in waders, hard hats and goggles, the director of proceedings with his clipboard and pen ordering this tree to be lopped at the trunk with a chainsaw and turned into the river as a deflector and that channel to be revetted, backfilled by machine and pinched.

Such projects are funded of course and have strict budgets and time deadlines to meet so they're military style operations following a well-planned strategic program of work designed to have the river improved beyond recognition in short order. To this end, presumably a blueprint is drawn up of desirable outcomes and maps are made that show where obstructions are to be introduced and at exactly what scale and these decisions are probably derived from existing flow data modeled into desirable shape by computer.

I wouldn't have thought them in any way haphazard or intuitive...

What's remarkable about such projects is just how many of them are focussed upon chalk streams and the like and with providing suitable habitat for fish such as wild brown trout, migratory sea trout and salmon. I would say that the vast majority of funding moneys currently spent on rehabilitating rivers are spent on those boasting both peerless chemistry and biology and the best chance of having a future as a prime game fishery should things be improved. It's business after all...

When I delivered the menu on offer for the fish of the Sowe I knew full well what a split viewpoint it would create amongst readers. Coarse anglers would see the superb food supply as the staple diet of roach that might grow very big in the future should habitat be created for them, but game anglers would not be concerned with that in the least viewing the river from an entirely different perspective. They'd  not see a roach fishery but a wild brown trout fishery in the making, because that's exactly what its habitat of pool, riffle and glide, pure water and hatches of the right kinds of flying insects suggest it could be.

I don't have a problem with that.

Many game anglers are not principally concerned with catching fish, per se, but are interested very much in the why and wherefore of how they are caught and the natural beauty of the places where they are found and beside getting up to their chests in water in order to fish rivers, adore small streams and their technical challenges like no other and tend to become deeply immersed in their continuing and future health in a way that coarse anglers sitting on the bank at a remove rarely do unless it's about improving access and creating comfortable habitat for themselves. 

That is why the vast majority of the spend on rivers goes where game fish are. Not because they deserve more attention than coarse fisheries — they don't — but because game anglers are so determined to have their rivers healthy they'll quietly organise and then move bureaucratic mountains to ensure they are. 

The list of their achievements is long, and when it comes to the rejuvenation of urban streams such as the Sowe, astonishing, because only they saw the potential early and considered what great fisheries they could be once again, pulled themselves together and created organised bodies to secure money and then worked very hard to achieve that end by getting stuck in where it really matters — at the level of the river bed.

We coarse anglers have a lot to learn...

And a very long way to go before we come close, let alone match their commitment.

Where it all began at the head of the new pool. Next picture just five yards along and I'll be up to my hips in it!

Driving my 'work' on the Sowe is a passion that I admit began as pure self-interest but without which I would never have bothered. I always adored this little river as an angler because it was such a challenge but so rewarding to fish and then somehow and for some reason I began to look deep into its shallows where I saw what was holding it back. 

Then naturally I wanted to see what could be done by trying to improve things but as cost effectively as possible, which in my situation means at the price of nothing but graft, utilising what is already there for free in the way of plants, rubble, sticks and rubbish, in an effort to harness and direct the tremendous power of flowing water to create a more natural course for a despoiled river and a better habitat for its very few but remarkable fish.

I think I've achieved something small but locally speaking, significant, though I can't claim credit for placing a few rocks under a bush and knowing what would happen after — I only remembered I'd done it when the floods came and never seemed to go away! It was nothing but a happy accident.

But it suggested great things could be achieved without funding of any kind — all that was required, actually, was the enthusiasm of a solo amateur who hadn't a clue what he was doing, the river taking care of mistakes by sweeping them away or ignoring them but taking advantage of small things, well-placed.

And finally, closure.

This morning I returned to the pool and peered keenly through the lens of its crystal waters to view the complex world of its aquatic life. They were still there, the minnows and perch, involved in a curious oscillating dance of threat and fear, retreat and peace. I suppose the perch are husbanding their resources, knowing they can ill afford to consume all the supply all at once. The roach were gone though, and that concerned me greatly because they were what started all this and why ultimately I bother with it. 

Perplexed and disappointed I made my way along where in the second, shallower pool I saw nothing at first but adjusting my focus I then saw hundreds of fish too tiny to be the adults of any species no matter how small — it was full of fry! Minnows I'd have thought, but the way the perch were eyeing up the parents they'll be needing all the recruitment they can get...

An hour later after messing downstream observing what hadn't happened and thinking what might happen should I do something else I decided to do nothing at all and made my way back up. There's a thin and fairly deep strip of water fringed with reeds and brambles I'd ignored all the while never intending to change a thing about it because once upon a time in my early reconnaissance trips I'd earmarked it as prime roach territory should it ever deepen enough and gain cover. 

I took a quiet look into the water seeing nothing but dark silt but then the dogs turned up crashing through the undergrowth when a flash of silver followed by a train of fish darting upstream gave them away. Dogs are good for that you know — springing fish from their cover! 

They calmed down, resumed order. Discovered and known to be around they were now quite easy for the eye to appreciate despite their camouflage. The dogs cleared off and I watched them for a while in peace when cruising along came an old friend — the only roach I know by name in all the world — who with an old white scab high upon his otherwise invisible back had given them away once before only to be caught himself a year on...

"White Spot!"

A roach by any other name and what not...

I'd fished for the very shoal he'd always been a member of just after the floods had subsided but they weren't where they usually were. I thought they'd gone elsewhere, to a place close by but one unknown to me, but now it was clear that they'd traveled much, much further from home than I'd ever have thought possible making it all the way up to a new one I'd helped create.  

That was enough. I'd built it, they'd come, and my work there was done.

But elsewhere?

Who can say what the next floods might bring...

And what I may bring to them.


My sincere thanks for sticking at it, staying with me through this long-winded thing, 

... but reading on, 

Jeff

Build It and They Will Come — Nature's Finest (Pt5)

Four years ago when I first took an interest in the Sowe I couldn't understand why it contained such a small head of fish but those few stretches of river I managed to find where the river had never been interfered with contained good mixed shoals with such large individuals in them. It seemed a puzzle because at that time I had no idea that fish living in rivers, and especially very small ones, have exacting standards when it comes to habitat. 

The infant river three miles upstream of the park, diminutive but pristine in every respect...

I thought fish simply required water, and in a large river with plenty of depth that might be the case, but as I walked miles upstream and downstream of the short natural stretch where I'd first found them and in search of more, it became abundantly clear that water alone was not enough here because they were absent if it was too shallow or lacked cover and that was the case pretty much everywhere else.

The mature & ancient natural stretch two miles below with its perfect unspoiled habitat

You may have become accustomed to viewing the river where these experiments of mine 
have been conducted as being far larger than it is in this picture. You'd be right in terms 
of width but not in depth. The river in the picture above has gained the water from one of 
it's main tributaries between here and there and yet it's much narrower, but exactly as it 
should be for the volume it carries — where I'm working is twice as wide but very shallow

I had to walk a full five miles downstream before I discovered another shoal. Between was a river that looked clean and healthy but hadn't any fish in it that I could see apart from one deep pool (the only deep pool!) bursting with minnows but without attendant perch. Upstream things looked far better but the only fish I witnessed there were sticklebacks and an isolated group of small fish I thought to be stoneloach living beneath a piece of roofing tile who vacated when boys took it away and used it in play, never to be seen again.

Sampling the menu

That's about when I started taking a look at what it contained in the way of available food wanting to know if it was a lack of that causing their absence or if it was actually lack of suitable habitat as I thought. So, I ran my first kick samples, getting into the river and throwing gravel up off the toe of my boot collecting what was dislodged in a small net.

I really didn't expect to find much and thought I'd go a long way before getting any result but in the first netful it was clear that not only was there food in the river and plenty of it, but when I got home, identified the species I'd found in an hour or so and checked them against a table divided into three or four classes indicating water purity — the bottom ranking able to live in sewers, the middling classes tolerant to degrees but the top ranking species highly intolerant of pollution — I found the food supply to be high class stuff of the finest quality...

Freshwater pea mussel I believe, and case-less caddis grub

I knew the little green caddis grubs for what they were without diagrams to check against but hadn't a clue about the abundant tiny clams because it was the first time in my life I'd ever seen anything like them living in a river. 

Besides them, all kinds of strange little creatures came up in the samples and when I took a closer look at the stones, limpet-like things I thought to be molluscs were attached to them... 

They were very common indeed.

Water penny — an aquatic beetle larvae

Freshwater shrimps and a mayfly nymph

There were lots of small shrimp-like creatures that looked like the sandhoppers I knew from my sea fishing days but alongside them another lifeform I hoped was a nymph...

Though not as common as the 'hoppers' they were present in good numbers and I was quite excited by them because I thought they might be mayflys, and if so one of the best indicators of water purity there is because they just can't stand any level of pollution...

As it turned out, my instinct was correct because they were indeed swimming mayfly nymphs, and better still, the little 'limpets' turned out to be water penny, an aquatic  beetle larvae and another top ranking species as were the tiny clams, a now quite rare species of freshwater pea mussel due to their need for very clean water.

All together it seemed the river was in sparkling good heath.

Swimming mayfly nymphs.

Then along came the first fish...

A bullhead! 

Only a very small one, but again, one of those species who don't like to live in unclean water. I've only ever caught a very small handful of these curious little fish with heads as big as their bodies but always in very clean rivers that support populations of wild brown trout. 

What I didn't expect to find was an earthworm below the gravel because worms live in soil, right? Well it seems they don't mind living in riverbeds either!

And then to top things off came one of the weirdest looking forms of life I have ever met. A large creature with long legs but who looked as ancient as the hills, as if he was actually a fossil rather than a living thing. Moving very slowly he crawled about clumsily on my hand unable to support his own weight out of water on his spindly limbs... 

I think he's a damselfly nymph who never emerged into the air and never would but missing most of his antennae and all his tail I'm not at all certain about that... 

I only wished I'd taken more photos, because I'm sure I found more that day than I realised.

I'm not much of a scientist when it comes to these things so I didn't count them all and come up with tables and the like, but was satisfied that the river held good food for fish life and plenty of it and even though you'd be forgiven for thinking it was anything but in certain ugly places, the river was actually very clean and its water pure. That was a revelation —I'd expected fair results, not excellent ones!

It was now clear to me that the fish grew just as large as such a small stream could support precisely because of its abundant high quality food supply in combination with good habitat wherever it was found — they couldn't make use of it where habitat was poor — but they could occupy the rest of river, breed and flourish, should what they need be created where for one reason and another it had ceased to exist.

To be concluded...

Build It and They Will Come — Dammed Hard Work (Pt4)

When I began messing around with rocks and sticks in other places I thought that things would be as easy as they had been — one small intervention, and "viola!" — total transformation of the river for 100 yards downstream. But, it isn't as easy as all that because placement is so critical that should an obstruction be placed badly then it has very little effect, as I was to find out.

There's lots of rocks available down there, none of which are natural to the stream. They are very useful to me though because they're handy portable building blocks that can be arranged on the river bed in various ways, the effect monitored, and if nothing of any consequence seems to be happening then the structure can be easily dismantled and erected elsewhere.

Causing the water to flow into a narrower channel

A groyne was constructed downstream at the same scale as that placed under the willow upstream just to see if rocks alone would achieve anything. Unfortunately the effect of a spate was negligible because the turbulence caused was directionless, just boiling over and dissipating uselessly. When it was at its highest, the groyne vanished below and the water ran straight over it as if it wasn't there at all — when it subsided no effect was measurable apart from a freshening of the gravel directly behind, none of which had moved even an inch.

As the water rose it vanished, the channel broadening and negating any effect it might have had. It needed to be far larger than it was to do anything useful but making large rock structures is not what I want to be doing.

The next willow downstream looked as easy to play with as the one that had had so much effect, so I dismantled the groyne and repositioned it below the branches, but this time installed a number of large dead branches between and plugged the gaps with dead vegetation, emulating what a heavy flood would achieve of its own accord.

When a spate did arrive the whole lot disappeared below the water and seemed to be doing its work, however, when the waters fell away I went back and saw to my dismay that it had achieved very little, in fact it hadn't altered the river bed and had hardly begun scouring the stones of their covering of grey/brown algae let alone move them.

As you can see, nothing whatsoever happened. The riverbed was just as shallow and immovable as before

The problem wasn't that the thing wasn't doing anything, it was. It narrowed the channel and caused all the water arriving from above to pass through a gap half the size of before. The trouble was that the water arrived at it with the heaviest flow along the far bank then passed straight on by without having much of its energy diverted. Consequently, very little turbulence was caused and what little was caused was linear.

The water arrives too gently at Willow Groyne 2,  all useful energy shooting directly along the far bank

Compared with the original successful experiment which in hindsight was entirely fortuitous, this structure was created upon knowledge I thought I'd gained from it. What I had failed to appreciate was that whatever happens downstream of such a structure is entirely conditioned upon what is already happening upstream of it and here the water arrived at the wrong angle which was no angle at all.

The original. Water arrives from upstream at a good angle, backs up, then plunges downward. At the point of the arrow the river is now a foot deep at normal flow but at the trailing edge of the rubbish raft now approaching four 

Taking a second look at the original willow groyne, it was clear the reason it had worked so well was because the heaviest of the water came it hard, backed up in a reservoir of pent up energy compressed by that coming along behind, then plunged downward taking most of its force to the riverbed where I now know it scoured almost three feet of gravel away creating a pool approaching four feet in depth with its deepest parts immediately below the obstruction where the bed now shelves away dramatically.

Of course this meant that if the second willow groyne were to work then something needed to be done to divert the water straight at it. So, I had a play about with rocks and came up with something — a double groyne in the approach way. In the picture above the first groyne is actually far smaller than the second and there to hopefully protect the area behind where rushes are already trying to establish and that I intend to consolidate with a backfill of rocks, gravel and silt otherwise it'll do more harm than good come the next flood, the turbulence caused ripping out the entire bed.

The second is a pretty substantial pile of rocks by comparison and designed to force the water across into the shallow area immediately upstream of the willow. As you can see, it does just that at low water. What it'll achieve at high water though, I haven't a clue! Though I do think it isn't large enough to really work as intended, but...

We'll see.

The last experiment was a loose rock dam that increased the depth of the shallow silted pool behind by a good foot as soon as it was built. In a spate it too disappears but the effect it has at the river bed is quite strong having shifted gravel and scoured it clean in no time. It doesn't seem to impede the progress of fish either because the roach and perch now resident in the pool 100 yards upstream arrived some time after construction.

The trouble is, the pool behind cannot get any deeper than it is right now of its own accord, and might even silt right up if I can't do something to create depth that will self maintain, and that's a headache, especially because I really don't have clue what I'm doing until I've done it, watched it, and learned my lesson!

The 'transverse' riffle is at top, the river between there and the dam remaining a very poor habitat for fish

Perhaps I'll dismantle the dam and use the rocks to create something else above the pool that will help deepen it enough for fish, because even raised by a foot in level it's not nearly deep enough for that without shady bankside cover to live beneath. What that might be though, I don't rightly know but I've heard that V-shaped groynes pointing upstream do scour well below...

Whatever I do attempt next I'm mindful of the need to not get carried away trying to further improve upon what is already improved out of all recognition. There's absolutely no need to interfere with the course between the deep pool and the rather interesting set of features created below — they can now take care of themselves and the river do the work of maintenance.

Everywhere else though? Until the watercourse there starts to approach the structural conditions that both you and I know comprise those of a healthy river fishery just from its outward appearance, then little offense can be caused by my experiments (except not having permission to run them!) but a great deal improved upon because as it stands it's a very long way from being one.

And that's a shame, because it certainly has the fundamental requirement that supports a good head of fish, and that's an abundance of Nature's Finest.

To be continued...

Build It and They Will Come — Supersoft (Pt3)

Perhaps the most amazing thing about the Sowe and its run-down, threadbare life over the last century or so is the fact that it was once horribly polluted by all accounts and for many decades, but it isn't now and hasn't been for some considerable time — and yet, its cleanliness has not been nearly enough to restore it to good health.

These are the ratings given for the river by the Environment Agency, or at least they were ~

Chemistry — A

Biology — B

Nutrients — err... think it was a C?

They've gone all European Water Framework Directive and removed the old General Quality Assessment stats from their website. Apparently the measurements they were using, presumably arrived at in inches, miles, pounds and ounces, pints, gallons and fahrenheit, weren't nearly good enough and now they'll need to get in line with the rest of the continent and measure river quality in something more metrically acceptable and with 30 rankings, at dizzyingly labyrinthine levels of detail... 

However, the new measurements do include one crucial class missing in the old-fashioned but intelligible 'O' level exam result style of the original data set, and that I do applaud because rating a river on water purity, pollution levels and food supply alone does not tell us that it supports a healthy head of fish, only that it can or can't, so the directive includes ratings for 'hydro-morphological conditions' or in plain English, watercourse structure, because if everything else is right but the structure is bad then the excellent other ratings are rendered worthless.

Something good out of Europe? Well perhaps, and we'll see...

This set of data will be enough to reduce the Sowe's status along much of its length from approaching chalk stream level to down in the sewer in one fell swoop because it recognises structure as what matters most to fish when it comes to making use of clean water and its abundant food supplies. In short, if it isn't a fit house to live in, it doesn't matter a jot how full the larder is.

And this was never more apparent than where I've been mucking about because the new pool has excellent river structure that fish have pounced on as fit accommodation whilst that just a few hundred yards downstream remains the same poorhouse it ever was and they ignore.  

The worst part is where the incline of the deep cutting through which the river flows bottoms out and there's a stretch that's dead straight, uniformly wide and far too shallow for at least a quarter of a mile. The problem with this horrible length is that floods no matter how powerful cannot change it because it is so heavily armoured — the gravel bed having such a smooth and even profile bank to bank that current forces cannot penetrate and lift it — spate waters gliding straight over as a massive smooth sheet.

Because there's no deviation there or anything that can deflect water, create turbulence, and have that gravel lifted and shifted, after the recent floods you'd swear they'd never happened because they had absolutely no effect whatsoever. It's just as dull and dead now as before. I don't know what can be done with it bar damming it with a weir to lift levels high enough above to create suitable conditions for silt sievers such as bream. 

However, because of its shallow incline it does offer the best opportunity for successful re-meandering work. If the channel were narrowed by half that would mean twice the depth of water in the channel but the same quantity flowing at the same speed through it. Make the channel sinuous though, and everything changes because the length of the river channel is thereby increased which has the effect of taking the same quantity through the same linear length of cutting more slowly but in a hydraulic sense, more powerfully. 

This kind of work was attempted in the past. Unfortunately it was a failure because it wasn't extensive enough nor was it sensitively done, but more importantly, was abandoned to its own devices and never followed up on once the funding moneys ran out...

A Brief History

As it passes into the local park the river nowadays enters an ornamental landscaped section backed up behind a weir designed to create a slow flowing broad channel of relatively deep water bordered by a continuous parade of mature weeping willow. Below the weir and for some distance our river then assumes what might be mistaken for it's natural course and channel but terminating in the most unnatural feature possible for a lowland stream.

This is the cascade weir built of blocks of red sandstone all of which were once part of probably Medieval stone buildings and walls destroyed in the Blitz on Coventry City. It looks quite good actually, kids love it as a playground and it certainly oxygenates the water below, but it shouldn't have to be there at all.

The complexity of the river in the early 19th Century. A meandering
course to die for but wiped away in one operation... modern attempts
at rehabilitation hardly compensating for such a stupendous, though
in times of war, necessary loss. It is impossible to turn back the clock.
(Asterisks indicate the stretch concerned, the red dot where I live)

The reason it exists there now is because of a special problem that it was part of an attempt at tackling...

In 1943 during the Dig For Victory war effort the river was straightened over many miles to drain the surrounding meadowland and make it fit for arable agriculture. This involved digging a new channel cut straight through all those troublesome ancient and tortuous meanders, designed to get the water through and out the other end as quickly as humanly possible.

Effectively, an open pipeline.

When in the late twentieth century it was decided that the river required natural appearances for its new purpose as a parkland feature, an attempt was made to create something like its old course and have it flow through that instead. The trouble with this was the wartime engineered straight course had reduced the effective length of the original river channel by half.

Just as a road descends a hill by a series of hairpin bends, the original course took its time about getting down the gradient, but this channel simply took the most direct route from top to bottom which was straight downhill, and at breakneck speed.

The answer was the cascade weir. This allowed the river upstream of it to be mechanically re-meandered in a natural looking narrow channel that is just the right width for the volume of water it carries and even a small wetland area was created that floods as it should at times of high water. The work was very successful there, however...

The cutting below the cascade weir was so steep-sided, deep and obdurate, that little could be done with it and so bays were cut in the banks and groynes placed above them in the hope that the river would re-meander itself under the power of spates to whatever degree it could.

The same scene a decade on. The bays filled back in, the groynes long gone, but meanders none... 

Hardly any trace remains of that effort today, the river having annihilated the ill-placed groynes, silted the bays and resumed its straight course, as of course it would because there's nowhere but straight through for high volumes of water to go in such a deep and direct cutting. It returned to being nothing but an open pipeline.

Back to the future

The pictures above were taken from the footbridge and show the river flowing towards us, the new pool way up in the trees at top, but the obdurate stretch I talked about earlier is immediately downstream of here.

Water is a strange substance. It is heavy but it is soft. It has no power to transform or do much except crush things under its own weight or dissolve what it touches or contains till it starts to move or something moves into it when it's the greatest and most powerful force on earth. It's no wonder that water in one form or another is always at the root of the notion of the sublime... and a sea in storm the most terrifying thing imaginable.

Put it this way. Make a perfect dive from a high cliff into the sea and you'll enter with barely a splash and feel no great force hit you as you do, but belly flop and your gut will split open from navel to chest. A gallon of water weighs 8lbs and more and if I dump it over your head it won't hurt even a bit, but the same gallon shot out of a water cannon at high velocity will send you down the street like a spinning top. 

The ripples don't represent flow, they are the disturbance cause by us. The dead channel in all it's glory

In rivers, this power is what changes things, weight and velocity combined hitting stuff and moving it about but then softly dissipating back into the main flow where once again, it regains the power of velocity and weight combined. It's unbelievably more complex than that though, which is why when the forces are simplified by straightening channels only then do they become easily understandable, quantifiable and predictable. Hence all the efforts to straighten so very many of our streams over the past century — because it tames the heart of the wild beast in them. 

Below the footbridge they removed the heart itself and because there's nothing to hit, the water simply passes by without effect and though in times of flood it will sweep you off to sea should you fall in, it's powerless to transform anything there because there's nothing so heavy or well fixed that it hasn't been swept away and what remains that can resist its force is too smooth and too resiliant — the solid and immovable gravel bed.

That is why it is dead and will remain so till something is done to improve its 'hydro-morphological' conditions...

But how on earth would I achieve such a thing alone, without a JCB, and with only sticks and stones and the power of water to play with? 

Well, I've been having a go at understanding the hellishly complex but subtly effective field of 'supersoft' river rehabilitation by going about things the only way I know how and that's to get stuck in (and very wet!) by messing with about with things found about the river just to see what happens when I place the stuff in it. 

So next time I'll entertain you with my recent discoveries and further experiments but in the light of the success of the creation of the pool, also their abject failures...

To be continued...

Build It and They Will Come — Above Beside Below Beneath Beyond (Pt2)

Having read my introduction to what was admittedly a naive but pivotal hydraulic experiment and its far reaching effects and consequences but whose success owes far more to luck than any kind of judgement, you might be uttering ~

'So what!'

"It's a river after all, and all rivers have fish in them. They were bound to turn up and populate that pool you foolish man..."

But, hold your horses and let me tell you the pertinent facts before you pass judgement.

When a dog paddles all the way from where we are now for a mile and half down stream before wetting its belly, then the river between is fit for nothing besides paddling dogs and sticklebacks. . . 

Excepting the diversions of water necessary for the building of flour mills every mile or so along its length during the Middle Ages, the River Sowe where I live in the Northern part of Coventry was once an entirely natural lowland river but in just the last century, because of flood control measures and radical simplification for the purposes of draining unproductive floodplain meadows in order to create population feeding arable land for the war effort, circa 1943, apart from the very few remaining places where such modifications were deemed pointless and the river left to its own devices, as habitat fit for fish it was utterly destroyed and has been a watercourse without them wherever its unruly nature was 'managed' for nigh on a century.

The second riffle created by the floods — below is dead water, but above who knows what might be happening?

The quarter-mile stretch running through Longford Park that I'm talking about held no fish whatsoever apart from the one well adapted to take advantage of very broad, everywhere shallow, arrow straight and evenly silted, left for dead watercourses — namely, sticklebacks — the one fish you will see living in such exposed and sterile waters because it's so heavily armoured, spiky, and inedibly throat-choking, it has little cause to fear birds who eat them live.

Believe me, I would have seen any other fish if they were ever there because I walk it often and take my water loving spaniels and myself into it — not just along it — and honestly, it was not only devoid of them but there weren't so many sticklebacks to see either it was that poor a habitat.

But would the pool hold proper fish just a few months after its creation? It seems highly unlikely it could, don't you think... ?

I trusted Mother Nature would fill the pool in time because she abhors a vacuum and all that, but my faith was rewarded earlier than expected with the sight of a heron lurking there, a bird that cannot afford to waste precious energy being in the wrong place.

I believed she was there for very good reason... but was she actually fishing... or fishing for opportunities? I wanted to know which, so I took a rod out during the snows of February and cast a bit of bread in it.

Nothing doing.

I don't know why I was so disappointed, but every bone in my angling body tells me that when a pool looks that good it'll hold fish. Of course, why would it? It hadn't been there long enough for that...

Moving down to the second pool — there beneath a submerged Sainsbury shopping trolly I had a few little taps that showed fish of some kind were indeed present. My optimism wasn't unfounded after all. But I had no intention of striking these bites, just wanted to see if I could get them as indicators of fish actually there, but then the proof took the bait and despite my best intentions, he hooked himself.

This significant little pioneer must have taken advantage of the floods as a route upstream to pastures new, I thought, and from my knowledge of this river I knew he'd successfully navigated a long and arduous passage through very heavy water from the first places where fish are to be found a mile and more downstream. I thought it remarkable he was there so fast but expected him to vacate the premises as unsuitable and just as quickly as he'd arrived when the waters fell.

Come Spring I wandered down the park and had a good hard look into the pool...

Immediately I saw fish. The heron was right to be there after all!

Couldn't make out if they were minnow, stoneloach or gudgeon, but they were present in number — twenty or thirty at least — much smaller even than the chub but fish all the same. A start in the right direction, for sure, and hopefully heading toward something better...

The first riffle below the pool, the second in the distance, a pool of its own between ...

Just a week ago the river was up again after heavy rain. Nothing like as big a spate as those of winter but more than enough for fish to travel by. It lasted just a few days but then it fell, clarified, and by last weekend was low and crystal clear once more.

Sunday morning I took Molly and Oscar out on what is now their favourite walk of all — in the river!

It was warm and bright, children were playing happily on the stepping stones above the weir, the trees  full of chirping and trilling birds. As we made our way through the bud burst thickets and new green shoots, I stopped above the pool and peered into its depths. In the dappled water I saw nothing at first and wondered if they'd gone but then a small darting fish crossed a light coloured stone and all was well.

Then, I caught sight of something more substantial... a fish with all the appearance and about the size of a roach!

It's not at all easy to see fish (let alone make photos of them!) in clear water when it's deep enough to suit them as a home, but of course that's exactly why the near four feet of depth the pool now possesses is ideal to for them to live in and why anything less will not be suitable.

If you can spot them easily — so can their aerial predators.

Rooted to the spot I shaded my eyes, let them acclimatise, when after a while I spied a fish even more remarkable than the roach I'd always wished would colonise the place, but the last I'd considered might.

A perch! And not just any perch either but a good half-pounder...

Then there were two, then three perch, and then roach, and yet more roach. As my eye adjusted and its focus sharpened it was clear the pool was populated with just as many large fish as it could feasibly hold and amongst them were plenty of smaller fish too.

But then — and this is truly amazing to me — it was as if the Gods of the River smiled and provided just what was required at the precise moment it was necessary for the purposes of this blog — a fishy photo opportunity!

Out of the depths came a small brightly coloured fish with blood-red tinged mouth, belly and fins who went belly up upon the surface then floated along in the current coming right under my bank, so I leant down and scooped him up in my hand — a plump cock minnow in full breeding plumage!

He came back to life in my palm and wriggled about a bit so I slipped him back but he floated away downstream disappearing over the riffle no doubt exhausted by the rigours of spawning a new generation of minnows for the pool but also food to sustain its newly arrived perch.

As I left the scene behind me, wading up the ankle-deep water in the spillway below the cascade weir and clambering over the rocks a tremendous feeling arose from deep down in my gut exploding into physical action as I punched the air and shouted at the top of my lungs...

"BUILD IT AND THEY WILL COME!"

Above the weir kids were now frolicking up to their knees in water, their parents sitting on the grass beside picnicking. Immersed in the tranquil seclusion below witnessing the unfurling miracles of aquatic life beneath, I'd clean forgotten about the public park beyond...

To be continued...

Build It and They Will Come — The Benefits of Clarity (Pt1)

Now that Summer has finally arrived and the Sowe, my local river, has fallen back to normal summer levels, the water has cleared and I can now appreciate the scale of change wrought by the endless winter spates and floods.

Raging continuously for nigh on three months, the river burst its banks three times during that period, was full to the brim the rest and fell very slowly even when the rains had abated due to the surrounding land being so utterly saturated by them. Witnessing torrents of water crashing through was awe inspiring then, not because the river is large and impressive, it's actually very small, but because the sheer power of flood waters are a spectacle to behold and a force that demands respect no matter how insignificant a channel they flow through.

The astonishing duration of those immense powers exerted upon a small structure I'd put in the river the previous summer I thought would have created something interesting in effect. What I failed to appreciate then was that the changes it had made to the stream would not only be more impressive than I could ever have imagined, but also life giving.

As they subside, the changes effected by torrents once as high as the topmost trails of accumulated rubbish,  start to become apparent — though only in Summertime would they be fully appreciated...

There's a small immature willow growing out the bank below a cascade weir to where I lugged a load of heavy rubble in the form of stones, boulders and bricks and threw it all underneath the trailing branches creating a small tapering diagonal groyne reaching half way across. The floods brought organic material downstream in abundance, branches, sticks, twigs, reeds, weed stems and all kinds of litter, plugging the gaps and causing the sapling and groyne to become a solid but permeable permanent structure...

Come Summertime the flow reduced, the water cleared and finally I could see bottom. The shallow glide above the tree narrows into a channel now and below is a deep enough pool for fish to live in, but who would ever know this remarkable feature created over just one winter was actually a happy collaboration between man and nature?

However, without the groyne this would never have happened because the trailing branches simply weren't large enough or strong enough wrapped in rubbish to hold much water back before they caved in, and just weren't low enough to make much difference where it really matters anyhow, which is at the level of the riverbed.

I failed to record the original thinking little would happen, but this is the scale of the stone block groyne placed beneath the willow. Insignificant in size, perhaps, but it turned out be hugely transforming ... 

The solid heavy material placed beneath not only helped plug the space between but also deflected the current and reduced the sheer weight of water pressure on the sapling which happily collected what must be half a ton of saturated debris, an obstruction that today looks as if it were created entirely by natural processes — the pool scoured below as if it had been there for centuries.

Of course, in wintertime I couldn't easily appreciate just how substantial the pool created by the floods really was because I couldn't see bottom, but now that levels have dropped and the water clarified I can, and it is remarkable. Before it was no more than a foot deep and my dogs would paddled about in it, but they swim around in it now because it's over three feet deep!

Where it had been a shallow and overly broad channel running straight through under the sapling, now  with powerful flow to one side dissipating into a placid swirling back eddy it had become a feature complex and diverse in flow structure, and in times of heavy water a refuge. I fancied it provided the best potential home for fish in miles because it's precisely a mile and half downstream where I know from long experience of this little stream that the first large fish are to be found, but here in this forlorn place they were entirely absent and for good reason, as we shall see...

As the waters fell the riffle became visible for the first time...

Well, the power of the water raging continuously for months on end had scoured more than just one pool. It had gouged out what must be ten tons of gravel from below the willow and deposited it as a central bank twenty yards downstream where the water passed over and began once again to shift material further downstream, scouring another longer but shallower pool and depositing the load as another remarkable feature at its terminus — what I can only describe a 'transverse' riffle.

Only when it had become fully exposed did a rapid narrow channel begin to form against the bank at bottom right — the river seeming to want to resume its meandering nature there

I wonder what will become of this in time ?

This is a pile of gravel that now blocks the river almost bank to bank when the water is low but allows water to fall out to one side in a narrow rapid channel where it flows straight into the bank and is now in process of gradually undercutting it. Of course the river is creating a meander and in time that exposed gravel will become a bed that plants will colonise completely (they're already starting to!) and eventually become semi-solid land except in flood when it will submerge.

What has been created in total is a transformed length of watercourse of sixty or seventy yards length that is to all intents and purposes a totally different stretch of river than it was this time last year. Below the transverse riffle the effects of the floods peter out and the river returns to what it was — a shallow and overly broad man-made channel with little flow diversity and no place fit for fish life, but above is a complex series of features that I just know provides just the right kind of home for them...

But, would they ever come live in it?

To be continued...

The pool.

A lovely looking 'new build' now — but will it be seen as fit to inhabit?