Tailwaters are notoriously small fly rivers but many anglers have a difficult time wrapping their heads around using patterns that represent this forage.  If you consider that tailwaters typically generate an enormous amount of midge activity due to the reservoir that feeds the river, it is presumable that a good portion of a trout’s diet would be very small invertebrates.  However, in the case of many tailwaters, there can also be a strong mix of caddis and mayflies and the challenge for many anglers is getting around the idea that a feeding trout would take a 3mm chironomid over another bug 4 or 5 times larger.

Fishing small during stained water.  GROF Guide, Nick Groves

All one has to do though, is observe what is going on in the air during just about any morning or evening throughout the season and you will conclude that more often than not, the air is filled with very small midges and, as these insects are aquatic born, their short life begins in the river as trout food.

So why would a 4 lb trout eat a 5mm chironomid?  Well, it boils down to density.  Consider this: why would a 150 tonne blue whale eat a 2 inch krill? Because it can eat thousands of them at a time!  To a trout that has taken up a feeding station during a dense chironomid emergence, the fish needs only to move inches at a time and essentially pull water through its gills to get a gutfull.  Remember that the trout has to weigh its options in terms of energy spent versus energy stored so the easiest meal is the most beneficial.  That is not to say the fish won’t eat a well-presented pheasant tail or caddis larvae during these occurrences but conventional wisdom tells us to ‘match the hatch’.

How do they see something so small?

We also need to consider that the river is the trout’s world.  Their ability to distinguish food items among all of the other debris that might be found in the drift is no different than ours.  My sense is, if you are a trout and you eat enough pieces of wood, grass or any other non-food item, you become more in tune and eventually learn what is good for you and what isn’t.  That said, the angler needs to be truly confident that the fish will see your size 22 larva and will, if presented properly, eventually eat it.

Further to that, and I have to admit that I was guilty of this, is the belief that as the water becomes more stained or off-colour, the trout’s ability to see small flies is exponentially reduced.  It would surprise many, myself included, to discover that their ability to see very small flies in stained water is remarkable.  Several years ago, I was fishing with my good friend and fellow guide Nick Groves, on the Grand River during a substantial algae bloom.  Now anyone that has experienced this will tell you it can get ugly.

Chironomid Larvae

Along with the dense algae in the drift is the accompanying stain and the visibility was no more than 6 inches.  I don’t often fish during these conditions but Nick and I had both been several days without a fix so we headed out.  I started with large flies like San Juan worms, isopods as large as size 10 and hellgrammites, thinking, ‘Might as well give them something they can find.’  We went an hour or more without a fish and as I was rummaging through my vest, I found a chironomid box.

“Hey Nick, how do you feel about going silly small in these conditions?”

Nick’s reply was typical Nick. “My sense says you’re pissing in the wind, but my research tells me otherwise.”  That was Nick’s way of saying, ‘While I have no confidence in the idea, I’ve read that you can”.

Now Nick is about as good a fly fisherman as I know so I ran with it and tied on a size 20, black and red larvae with a little U.V. mylar wing case. Confidence is a funny thing and under normal conditions, I’d fish this pattern all day long but I have to admit that I wasn’t really feeling it here. That is until I hooked my first fish.  “I’ll be damned!”  Perhaps fly fishing’s greatest fringe benefit is that you cannot stop learning cool stuff and this, to me, was a game-changing epiphany.  To think of the hours that I spent guiding and fishing during these conditions and didn’t take this route! Nick switched up and together, we managed several more good fish on very small flies.  After finishing up, both of us reflected on what had happened, concluding that we had both had learned something that neither of us expected.

What is “Small”?

Many anglers consider “small” to be just about any fly south of a size 14 and struggle with even 16’s or 18’s.  However, if you talk to anyone that fishes a tailwater regularly, they will tell you that 16’s and 18’s are the norm, and small doesn’t start until you have to tie on a size 20.  On my home water, with the exception of our grey fox and brown drake hatch, I will rarely fish anything larger than a 16, regardless of it being on the surface or while high stick nymphing.

An assortment of patterns under sz 18.

Looking back to when I started trout fishing in Southern Ontario, I typically used only those patterns that I fished during my time out East.  Wet flies like Montreals, Alexanders, larger pheasant tails and so on, were all I owned so my fly selection was limited, therefore, limiting my success.  It wasn’t until I began talking to and watching the anglers around me, that consistently took large trout, that the light went on and through conversations over warm beers on the river bank, did I really begin to have greater understanding of the requirements needed to take big fish on a regular basis.

Now, this is not to say that large, ‘in your face’ streamers don’t work because they do, but adaptation in trout fishing is paramount.  One needs to consider conditions, river dynamics, aquatic biology and a myriad of other factors to become a successful angler but it starts with trial and error.  This winter, take some time and tie up some small bugs and when your usual suspects are not producing, try them.  Small flies are not a bravado thing. It’s not about taking a large fish on a size 22 chironomid to brag about, but more: an extension of your current arsenal.  But make no mistake, this collection of minute patterns will be a game changer.

What you need 

The right materials are key!

Dressing these patterns is not difficult if you have the right materials.  I typically use 16/0 Veevus thread for the body and as my finishing thread, as it is available in a variety of colours and is very forgiving for small flies.  I also like Uni-Trico as it lays very flat but is not as strong as the Veevus product.  Tying with light thread like this requires a touch so don’t be frustrated if you break some.  Eventually, you will develop it.