"We'll have to dust off the fish when we catch them," a buddy quipped after I asked about stream conditions. That told me the water was low — seriously low — and that we'd have to tailor our approaches accordingly.
Low water in a trout stream offers definite advantages. The fish stack up in predictable locations, streams become easier to wade and to work efficiently, and more areas often become accessible. The same conditions, however, bring significant challenges. Fish that you can see can also see you, and they can give every would-be meal a really good look before committing. Trout turn easy to spook in extra low-streams, and they can act awfully fussy.
More important than a determination as to whether low water is good or bad is understanding how changes in conditions alter the behavior of the fish and utilizing that understanding in devising approaches that work to catch fish. Low flows tend to go with trout fishing late in the summer and early in the fall. Rightly considered, the level of the water will impact the spots where you concentrate efforts, the way you move in the water and the offerings you choose.
The biggest, deepest pools in any given stream tend to hold the largest concentrations of fish when the water runs low. However, fish that hold tight to the bottom in the slack portions of big pools tend to be very difficult to catch. Those fish often are resting — not actively feeding — and while they certainly would eat if given the right opportunity, they aren't looking to chase and they get an exceptionally long look at anything that comes their way.
That said, current lines at the heads of deep runs and swifter runs in the tail-outs of the same pools commonly hold more active fish and warrant careful attention. Even in the mid-sections of pools, if you're able to see boulders, downed trees or other obstructions that provide holding areas for trout, you sometimes can present a bait so the fish don't see it until the last minute and that can prompt reaction strikes.
In other parts of the stream, fish congregate in any section that has even a little stronger current than the rest of a stream, tucking themselves behind features that break the current, holding tight to the bottom or hugging current-swept banks. Riffle-type areas that break up the surface and help conceal the fish also tend to hold trout, even if the water is fairly shallow. Finally, don't overlook areas that stay shady through much of the day. The shade actually serves double duty for the trout, providing a form of cover and keeping the water just a tiny bit cooler.
In gentle streams that wind through fairly flat forests or fields, subtle distinctions become extra important. In such a stream, any hint of added depth, current or cover is likely to hold trout when flows are low, so well-calculated approaches and good lure selections become absolutely essential.
Stream stealth carries some degree of importance in virtually all trout fishing situations, but its importance goes way up during late summer and early fall, when streams tend to run extra low and clear. Without much question, the best way to make sure a fish won't take your offering when the water is extra low is to give away your presence before the fish ever gets a glimpse of your lure.
You sometimes can catch multiple fish from the same run if you remain undetected, but once they realize you're there, the fish normally will stop feeding for a while.
Specific stealthy approaches vary substantially from stream to stream based on the size of the creek or river, the steepness of its shores and the amount and type of cover that's along the banks or in the streambed. As much as the situations allows, though, work from a little longer distance than you sometimes might, stay out of the stream or along its edges and move slowly, avoiding noisy splashes and abrupt movements. Use natural cover for concealment when you can, stay as low as possible, and dress in drab colors.
Whenever possible, begin at the downstream end of the section you want to fish and work upstream, casting generally upstream and working baits back to you. Trout face upstream to maintain position in the current and much of their food comes drifting downstream to them. Therefore, such an approach causes the fish to see your lure moving naturally downstream with you remaining behind the fish. Work everything within casting range and then move carefully upstream, casting as you go but watching for key areas that you need to approach with extra care.
As valuable as long casts can be for keeping you away from the fish, accurate casts that don't make too big a splash are even more important. In extreme low water, you might only get one chance to surprise a trout that's in a key ambush position, so consider carefully where you want to cast, and get yourself into a good potion to make an accurate delivery.
Most low-water offerings are on the small end of the spectrum, so use ultralight or even micro tackle if you're spin-fishing and spool your reel with 2- to 4-pound test line. Along with being less visible to the trout and allowing small lures to move uninhibited, lighter line allows for longer casts. For fly-fishing, low water calls for longer than average leaders with fairly light tippet, again for the sake of making subtle and natural presentations.
Because the trout get spooked easily when the water is low and because streams tend to "fish smaller" than they would if more water was flowing, anticipate covering more water than normal in a day. Once you've worked a pool for a while, the fish typically will shut down, and you might as well move upstream. You usually can come back and work the same pool again after the fish have had time to settle, but continuing to fish new water tends to be more productive.
Given high flows or even average water levels, flash and action are important for getting the trout's attention and prompting them to attack. Under those conditions, and day-glow bright colors are popular and effective. Low flows, however, change everything. Whether you opt to swim spinning lures, drift flies or even fish with natural bait, the best overall fish producers are somewhat subtle and highly natural looking. If you have a choice of a few different sizes for fishing low water, the smaller size option usually will be best for the job.
Good jig choices for low-water fishing include 1/32-ounce or smaller marabou jigs, Lindy Watsit Grubs and Fuzz-E Grubs and Mister Twister Micro Shads and Nymphs.
If you like spinners, use a No. 0 or 1 Mepps Plain Aglia, and Aglia Spin Fly or a 1/32-ounce Rooster Tail. Many spoons are too big and flashy or need to be worked too quickly for low water conditions, but the smallest and lighted spoons can still work well. Plugs likewise have a place in low-water fishing. You just have to stick with diminutive crankbaits and minnow baits, such as Rebel Teeny Wee-Crawfish and the smallest Rapala Minnows.
Regardless of the specific lure you choose, use muted colors, ideally in patterns that suggest crawfish, aquatic insects and other natural forage that live in the waters where you are fishing. Lacking specific knowledge about what lives in a stream, stick with shades of brown, olive and gray or basic black. Ideal color patterns allow a lure to go unnoticed until it gets pretty close to the fish and then looks like a real meal when it does get spotted.
Most of the flies that work the best under the same conditions are also natural, and small flies generally work best unless some specific large insect is hatching and the fish are keying on the big bugs. The major exception for fly-fishermen is that on many streams a bulky grasshopper imitation can be highly effective and draw hard strikes late in the summer, even when the water is very low and running super clear. Cast right next to the bank, ideally next to a grassy bank or between downed trees, where trout expect misdirected terrestrials to land.
'Hoppers and hatch-matching exceptions acknowledged, good flies for low-water trout mostly include small bushy dry flies with natural tones, such as an Elk Hair Caddis or an Adams, and small and lightly weighted brown or tan nymphs that have a generally "buggy" look.
Of course, the most natural type of offering you can present for trout is a legitimate natural offering such as an earthworm. When the fish turn extra fussy and reject even the smallest and most subtle jigs or spinners, put a live worm on a simple split shot rig and dead drift it through runs that are likely to hold fish. Even with live bait, though, light line and natural presentations are important.
If you have enough water flow to drift lures, flies or natural bait in the current, the most natural presentation often is to cast upstream of likely trout lies and let the current do the delivery work.
When many streams run really low, though, some fish-holding areas won't have enough current to rely on dead drifts, especially for lures that have a little weight to them. In such cases you have to reel slowly or work the bait with lifts and drops. Even if the current is too weak to do all the work, let it aid in your presentation as much as possible because the trout will still orient upstream and look for offerings drifting toward them in the current.
Small crankbaits and minnow baits typically need some imparted action, but the best low-water presentation usually comes from a steady retrieve that moves the bait slightly cross-current or just faster than the current. Fast retrieves and the added twitches that convert lookers into biters under other conditions are more apt to send trout scurrying for cover when the water is extra low.
The biggest exception to rule of slow, current-driven presentation occurs when you have a good overview of boulder or other piece of cover that trout hide behind and that limits the fish's upstream view. If you can land a cast far enough upstream for it to go undetected and crank it quickly so that when the fish see the lure first it is nearby and looks to be getting away quickly, often they will ambush the bait.
Regarding locations, approaches, lures and presentations, pay careful attention to the things that produce and look for places where you can repeat the pattern. Extreme conditions of any kind concentrate fish in specific types of areas and force them to act certain ways, so effective patterning can heed extra big dividends.