A heavy flow with the peak of the spate passed, with more than a touch of colour will dictate that the fly is fished around as slow as possible in the main belly of the pool close in and near to the bottom, this calls for a fast intermediate fly-line, and sometimes plus the use of a sink tip, and a fly with a bit of impact. Patterns with a lot of orange and yellow in with a gold or silver body are fine, orange and yellow hair wings tied on aluminium tubes and Waddington’s of about three inches, or doubles like the Boyo around size 6/8 with a long tail.
The fish will hardly ever be out in the main flow when the river is in this condition, they will be creeping up the easier routes slowly, usually quite close to the bank. Casting across the river to squarely will be futile, before the fly has reached the correct fishing depth it will be whisked away at speed by the current. Much better to cast at a shallow angle and keeping a few yards of slack behind after the cast has been made, which is then thrown into an upstream mend the moment the fly-line touches down. The fly now has more time to sink nearer the bottom where we want it to be, by keeping the rod out at right angles to the bank the fly-line under tension can now be guided very slowly back in toward our bank.
As the fly reaches the slacker water near the bank, a retrieve (figure of eight or a slow steady pull) just fast enough to keep tension on the rod tip and thus the fly swimming correctly is maintained until we have the correct casting length. Without pausing the rod is raised slowly and back to the roll casting position, most of the fly-line at this point will have come up near to the surface due to the pressure of the current acting under the fly-line. A roll cast back along the bank is made to put the line onto the surface of the water; before it sinks back under the surface the appropriate cast is then performed moving down the pool a cast a pace.
As the river level drops and clears further, a smaller more subtle fly can be used, something like a Boyo, Munroe Killer or a Willie Gunn in its various guises size 10 to 12 between one and two inches fished on either a slow intermediate or a fast sink tip on a floating line. In the easier flows the fish will be using the full width of the river to travel, although they tend to use certain paths through the pools at different heights of water.
Local knowledge of pools is essential if it is to be fished effectively, there are running lies that salmon will rest for a short time, and residential lies for the more long term, these can change at different water heights.
Salmon, when the water is at this height do not hang around long, only slowing down when they reach the middle beats of the system. By selecting the times we fish can help enormously, to be there two hours before the tide and two hours after on the lower beats will increase our chances. Begin by starting at the head of the pool, where the faster water is running out of the pool above, the neck. Initially put a short cast out into the flow, while standing still make each cast a little longer until you have a good working line out that covers a good part of the width of the pool. Depending on the flow speed, especially for the fast water at the neck, cast a shallow angle with an upstream mend to slow the fly down, by holding the rod out toward the stream and slowly following the fly line around can also help. As we move through to the main belly of the pool which could be anything from a few yards to a few hundred yards, the flow begins to lose its pace as it becomes wider and deeper. The slower the water the more square the cast is performed, and keeping tension on the fly line by a slow figure of eight retrieve. Ideally the fly should be fished as close to the bottom as possible traversing the current slowly and to look like its struggling to make its way upstream, prospecting any potential lies there might be.
Every fifth cast and pace or so down the pool, throw a really square cast that will come around quite fast with the aid of the current on the line and use a fast figure of eight or a strip retrieve. What we are trying to do is not only cover fish that are on the normal lies, but to have a chance at goading a running fish which tend to travel a little higher in the water. Often you can see these fish moving up the river showing frequently, there is nothing guaranteed but just every now and then it happens.
As we fish through the main belly of the pool we arrive at probably the most productive part, the tail.
Casting at a more shallow angle now as the flow speeds up and disappears into a vee and down into the next pool below. Salmon can often be seen in this vee, as they come up from the fast and rough water below, they then slip into the easy flow above and momentarily rest for a short while before continuing their journey. The giveaway sign is the fish makes a porpoising movement, a head and tail, fish generally are very good takers when this occurs, more so at the tail of the pool than the main belly.
Other signs of fish are salmon leaving the water completely, crashing about, this usually happens as the water is getting lower. Fish start to lie up in the pools waiting for the next rise of water, or they may be content to stay there until the final rush near spawning time. What sometimes makes them do this is when new fish arrive in the pool and disturb them; they tend to be more alert and aggressive for a short while and ready takers, a fly with a touch of red can sometimes be deadly.
It pays to experiment with different patters of fly, most patterns work most places, it is how the fly is presented and fished effectively that counts.