Taking High Water Trout

March 10, 2011 By: Chuck Stranahan

Brown Trout

Trout like this one can be taken during high water by anglers who are cautious and persistent. Larry Javorsky photo.

THE WATER on my home river, the Bitterroot in Western Montana, is rising. Given our light snowpack this year, it will settle rapidly into fishable shape again. I’ll probably be on it, though, when others are saying “Too high.”

Anglers who “know how” generally do well during high water. And they usually have long stretches all to themselves. It is happening again this year during the pre-runoff period. When the river is too high to float, the river will be all but abandoned.

Until it is blown out, fishing in the middle of the day and stripping buggers near the bottom, drifting big heavy nymphs, or early on, fishing the Mother’s Day Caddis that were active midstream, work well enough. When those methods quit producing, all but the diehards quit. A few of the diehards will continue to score. Big-time.

Jim Allred is such a diehard. He recently invited me to float the West Fork with him. As he wrestled the raft through a shooting gallery of midstream boulders, Bill Capps and I searched for trout along the soft edges with big nymphs. We didn’t use extra weight, and we didn’t fish the heavy main currents, in places where trout may have been holding just days before. Pickings were slim, but my first fish of the season came that day on a stonefly nymph. It was a 3 ½-pound rainbow.

Up to a point, during high water, trout will hold deep in familiar runs. While they’re there, fishing aggressively and stripping big stuff across the bottom is productive. As the water rises, at a certain point, this method all-of-a-sudden fails. Things are still OK on one day, and on the next, it seems that the fish have moved out.

That’s exactly what happens. They have to go someplace, and they have to keep eating. High water pushes them out. And as water levels rise, temperatures drop. Trout are sensitive to that.

When water is high and temps are marginal, the window of opportunity is narrow and may exist for only a couple of hours during the pleasant part of a day, on the heels of a storm, or during a light, warm rain. You have to be there when the time is right. Finding fish, and not spooking them, is equally critical.

During fishable high water, during pre-runoff, post-runoff, or a midsummer gullywasher of a storm, trout move around. They won’t hang in a roaring torrent, one that was a quiet pocket a few days ago. They find new lies, and while they’re in them, they’re skittish.

Trout move around more than we think they do. They will move from the depth of a far bank to the shallower inside bank as water levels increase. As temps drop, they’ll move away from swifter holding currents, where the water is moving at about three to four feet per second, into water moving barely a foot per second.

This business of current speed is important, but overlooked by many anglers. Moreover, it is easy to measure. Put a cast on the water, point your rod tip at your fly, hold it stationary as the fly drifts, and begin counting: “One-thousand, two-thousand, three….” Estimate how far your fly has moved each second. Guessing involves its own brand of vertigo. What looks to me like three FPS current often turns out to be more like six, if I check using the point-and-count method.

High Water Trout Fishing

Bank-full rivers require special tactics. Leave the whitecaps alone, and fish the edges. Chuck Stranahan photo.

High water trout often cruise and hold in water barely deep enough to cover a dorsal fin. When fresh snowmelt hits the river, you’ll find trout along a near bank, sunning in slow moving water. Sometimes they’ll be in side channels that are dry the rest of the year. That favorite run, one you’ve taken fish from all summer long in seasons past, becomes a swift, noisy sluice during high water. That big long gravel bar which borders the run may be under a foot of water. Until they get spooked, the trout from the run will move onto the gravel bar, where food is washing into them. At the same time, they sense that they are exposed.

To approach them, you have to forget the roaring torrent beside you, and fish to them cautiously, as if they were in a mountain meadow stream. The fish in such lies are vulnerable, not settled into their new surroundings, without their customary amount of cover, and easily spooked. They will feed, though, until descending water temperatures from the snowmelt render them semi-comatose. They will hold or cruise in the shallows until spooked, and may not be available again until the following day.

Don’t waste your opportunities. Wade cautiously. Cast carefully. This is not flood stage “Yee-haw!” slap-the-banks-with-Bitch Creeks fishing. That will come later.

Bitch Creeks and other large nymphs will work, though, if swung into the quiet lies from the main currents. So will smaller nymphs, which I prefer, as they are easier to control during the drift than larger ones. Trout will position themselves where nymphs will be brought to them by the natural flow of the current toward shore. Spend some time studying the river. Look for a place where the current washes toward the edge in shallow, slow-moving water. Fish there.

A favorite trick of mine is to use a small streamer, about size eight or ten. I clamp a piece of split shot a foot above it. I make a kind of casual flop of a cast into a roaring torrent, and let the small fly swing into a lie where I think there is a fish. Sometimes this might be right below a submerged willow. I get hung up a lot, and I lose a lot of flies.

I’ll let the small fly sit and swim in the slow current for a few seconds, maybe half a minute if my nerves are up to it, adjusting the depth and position of the fly with my rod tip, raising and lowering the shot. After a while I’ll lower the rod tip and move the fly. As I do I try to put myself into the position of that imaginary baitfish, and think while I retrieve “Ohh, goodness! I see a big trout! I think I’ll scram!” I move the fly, not quite far enough to avoid disaster, trying to inject that note of panic in my retrieve, and wait for the response.

Sometimes I feel a solid chomp. Sometimes I snag a willow. Sometimes there is nothing. If I can, I drift the fly back into the lie and try again. I might repeat the cycle several times before I take the fly out of the water. Sometimes it takes a little agitation and persistence to get a high-water trout stirred up enough to strike.

Streamers give me more options than nymphs for this kind of fishing. I can keep them moving, or let them hang still and swim in the current. I can try to trigger a strike response from a lethargic fish that wouldn’t bother with a naturally drifted nymph. I can cover a lot of water. But I always carry a batch of nymphs, dries, and emergers, and look for any opportunity to use them.

During pre-runoff and post-runoff high water here in the West it’s not uncommon to see localized hatches of several insects. There are gray drakes. There are March browns and smaller blue winged olives. And there are my personal favorites, caddisflies.

The so-called Mother’s Day Caddis hatches were on the river in flurries, right at the appointed time this year. As caddisflies tend to hang around for a while after hatching and can appear on the water at random, they can be fished reasonably well just about anytime. And, they scoot along the water. Scooting a Caddis Variant over the lie of a trout holding in pre-runoff cold water is likely to wake him up and make him strike. When nothing is on the water, it is usually more effective than dead drifting a small mayfly imitation.

The dry fly activity, if you hit it right, can be superb. When it isn’t, there are always small streamers. To use the hackneyed phrase again, think outside the box. Explore. You can expect to do well during high water for as long as you can find water along the edges to fish.