Reading The Water Series - The Long Flat

finding fish Jan 23, 2019

Reading the Water is an expansive topic since there are many different types of water out there.

Big pools, shallow riffles, pocket water, swift runs, are all types of water you may fish in a river or stream, but we're going to start by looking at what we think of as "flat water." This type of water is a piece of water that is flat without any white water, chop, or riffle upon it. Most flats will feature a transition from another type of water to a flat. Sometimes long sections of a river will be flat with only rock ledges, weed beds or sharp bends to break up the flow.

It's very common for a riffle to slow down into flatter piece of water with relatively slow flow. A flat can be deep or shallow, and to be clear we're not talking about saltwater flats whereas in saltwater fly fishing. That's completely different and not what we are addressing here. A flat piece of trout water in a river typically has very little current.
The Railroad Ranch section of the Henry's Fork in Idaho is world famous for large, tough trout in slow, clear water
The reason we've chosen flat water to begin our discussion of reading the water is that this is the type of water that draws the most anglers. We see this on our home water as well as wherever we travel to fish for trout. There may be miles upon miles of riffles and pocket water with a few scattered anglers, but almost any patch of flat water will have a fly fisher casting over it. All of us attempt to put ourselves in the mindset of a trout so it just stands to reason a big, long patch of flat water will hold a ton of fish. Just look at it! Fish don't have to fight the swift current. If we'd choose it for a swimming hole then surely a trout would too. A bonus is that this is the most likely place you'll see fish in the water. You can see them, so you know they're there.
Notice the distinct drift lines of foam on the water. All originate where the water flows between gaps in a submerged rock ledge.
There are absolutely trout here, but we have to go a little deeper into the mind of a trout. A trout not only has to feed itself but also protect itself from predators. One of the most attractive things a long flat gives a trout is unparalleled visibility. The calm, slow, clear water allows the fish to see things outside of the water quite well. Much better in fact than holding areas in swift water. Slow water allows a trout to see your well-practiced fly cast, your favorite brightly colored fishing shirts, and caps, and even count the legs and body segments of any fly before they eat it. 
Congratulations! You've found fish! Unfortunately, you've chosen the toughest fish in the river. Don't despair, though. We can work through this.
The first thing you should do is match your tactics to the water. That means take it slow in a slow stream. Nothing will spell failure faster than rushing right into the water and casting the fly everywhere as soon as you can. It's much better to take a break and spend a bit of time observing things. It's always important to see fish, but don't expect to see every fish even in super clear water. Look for the best places for a feeding fish to be. Slow water is an ideal location for trout to rest. So many fish may not be in the mood to feed, especially if there are no bugs hatching. To adapt an adage, you can put a fly on a trout, but you can't make him eat. Find the areas where a fish is most likely to eat and focus your attention there.
Watch for drift lines indicated by bubbles and other debris in the water are isolated by the current. Typically there will be one long drift line in a long pool or run that stretches from the swift water at the head through the slow water. Rock ledges may have breaks that create feeding lanes where water flows. Sharp bends in a river cause most drifting items like fish food to become pushed primarily along the outside bank. These drift lines will carry the bulk of nymphs, hatching insects, and wayward terrestrial bugs like ants or beetles that have found themselves in the water. 
Drift lines are the most reliable places to find a fish but the further upstream you move the more likely you are to find a motivated feeding fish. Remember that trout are not schooling fish and are NOT team players. One trout cannot eat the same piece of food another trout eat, so they're all competitors for the limited resource of food. Imagine 100 hungry middle schoolers in a lunch line at school. If there are 50 pieces of pizza, 20 peanut butter sandwiches, and ten servings of broccoli surprise you can imagine the elbowing and shuffle in the line. There's not enough food to go around, and only half the kids will get what they want.
As the middle schoolers, a hungry trout is far more likely to be near the source of a drift line than further back down the line. That's a valuable illustration but not 100% applicable to trout. Not every trout has to feed at the same time as a class of kids in school.
Trout will often feed along the outside edge of a bend since the current pushes food there. Finding a casting spot on the bank is also an excellent opportunity to stay out of the water.
There may be nice fish at the head of the flat, but if there aren't many bugs on the water, they may be smaller fish taking advantage of the opening. Larger trout will usually feed under the most advantageous circumstances like during a heavy hatch and rest to conserve energy the rest of the time. Another thing to consider is that more fish will be feeding in more locations during a good hatch when food is abundant. If food is plentiful, a large fish will likely take up a position that allows it to get the most food for the least effort. This feeding spot may be near the head of the run but is more likely to be further back in the slower current. Most of the bugs and feeding fish well be in the drift line, though.
Once you've identified where to cast, your next task is to decide how to cast a fly there without attracting any attention to yourself. Remember that fish can see you our your cast better in the flat water environment better than anywhere else. Stay out of the water as much as possible and move along the banks whenever you can. Wading in calm water may create splashes that fish will hear. Wading too fast can also generate a push in the water out ahead of you that fish will feel. Once again, adapt your movements to the water. Slow water calls for slow wading or not wading at all. Water that is barely moving calls for exceptionally slow wading. You may choose to step out of the water as you start moving upstream.
Fish can see your fly cast quite well, so it's critical that you are deliberate and highly targeted with your casts, so you don't spend any more time than necessary with your line zipping back and forth over the fish. You should have already determined the best place to cast so make every effort to put the fly right there and nowhere else. If the fly doesn't land exactly where you wanted it, leave it. Let the fly slowly drift clear of the area and cast again once it's well clear of the fish. Dropping your fly then picking up to cast immediately creates quite a disturbance so that can tip fish off to your presence.
If your cast didn't result in a take let it continue to drift away from the target zone and stick with the game plan; take it slow. Watch the target area a little more. Was your cast really on target? Did the fish move? After a bit of a pause try again. This situation is a time when a companion who can see the fish from another vantage point is valuable as a spotter. If a buddy can tell you that your fly was on target or not makes a huge difference. Even better, if they can tell you whether or not a fish showed interest in your fly, you can start to hone in on what a fish wants. A spotter can also tell you whether the fish is even there or not. Better to move on if you know the fish left.
Calm flats in a river are among the most difficult place in a river to catch trout, but if you can catch them there, you'll do even better in other areas we'll be discussing in upcoming posts.

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