Spewing out from dam gates like giant spring creeks, tailwaters offer some of the greatest trout fishing in America. Impounding the rivers upstream enhances the nutrient content of the water, creating a rich habitat for the fish and a year-round growing season. Water is released at the optimum temperatures trout prefer, keeping the rivers cool enough for feeding during hot summer days and warm enough during winter.
Steady dam releases are best, but the fishing can also be fabulous where the flow fluctuates daily. Tailwaters are often found in southern locations where only marginal warm water fisheries existed before dams were built and the currents often flowed silty and brown. The White, Little Red, and Hiwassee rivers are three famous examples.
Even in the West, where quality trout fishing is plentiful, some of the best sport takes places on tailwaters such as the Bighorn, Wind, Green, San Juan, and Colorado. In the Northeast, tailwaters like the Delaware are famous for their large, selective fish.
Nutrient-enrichment, perfect stream temperatures, clear water from the settling effect of the lake upstream—all of these factors help make tailwaters superb fisheries.
The variety of foods available to tailwater trout is immense. There are populations of baitfish such as dace, shiners, sculpins, and chubs; aquatic insects including mayflies, caddis, and midges; an abundance of terrestrials washed in from land; aquatic worms; and finally, substantial populations of crustaceans such as scuds and crayfish. A well-stocked vest for tailwater fly fishing should carry imitations of all these important foods.
Use these to imitate baitfish, fed on often by trout when waters are high or falling just after dam gates are shut. Sculpins, Woolly Buggers, Zonkers, and Marabou Muddlers are good choices, size 1-6. Fish them on a hi-density sink tip line with a 5-6 foot leader or a floating line with a few split shot crimped on 12-18 inches in front of the fly.
Use short strips, pausing often, so the fly drifts deep. Keep the rod tip low to the water for solid hook setting. Work the bank, eddies, and below rocks where fish can escape the current.
Nymphs, crustaceans, and aquatic worms
These three groups account for more trout caught on tailwaters than any other. Fortunately, they can all be fished in an identical manner.
Use floating, weight-forward taper lines, 4-7 weight, coupled with a 9-10 foot leader. Squeeze a strike indicator on just below where the leader joins the fly line and use either weighted flies or split shot 16 inches above the offering.
Scud, sow bug, and crayfish patterns, mayfly nymphs, caddis pupae, can all be effective on tailwaters. Also, stock a few Gold-Ribbed Hare’s Ear and Pheasant Tail flies, plus the famous San Juan Worm, which imitates aquatic worms as well as earthworms.
Some of these patterns may produce better one day than others, and certain types of water such as riffles, dep pools, or stretches along the bank may give the nod to one over another. As a rule, go with larger flies (sizes 6-12) during high water, smaller ones (14-20) during low water when no power is being generated at the dam.
An upstream or up and across dead-drift presentation is best. Sometimes you’ll even find trout tailing like bonefish in shallow riffles, backwater flats, weed beds, and eddies as they search out these crustaceans and nymphs. Drop the fly delicately ahead of such fish and twitch it lightly as they approach.
Surface Flies—aquatic insects & terrestrials
Hatches of mayflies can be heavy on nutrient-enriched tailwaters, particularly those that have regulated water flow instead of violent daily fluctuations. Important hatches you might encounter include a variety of Olives, Pale Morning Duns, Hendricksons, Tricos, and various caddis species.
Best patterns for mayflies are those tied in Thorax, Comparadun, and Parachute styles. For caddis flies it’s hard to beat the Elk Hair Caddis in a variety of sizes in olive, brown and gray. The Adams is another good all-around pattern to stock. When trout want little food, you’ll have to scale down to tiny midge patterns such as the Griffith’s Gnat, sizes 18-24.
Terrestrials are the final type of dry fly to stock. Because of the rising and falling water levels, even more land insects wind up in tailwaters than normal rivers. On the Green River in Utah, anglers pound up big browns and rainbows with large Cicada patterns and chunky Chernobyl Ants. For day-in and day-out fishing on most tailwaters, offerings such as hoppers, crickets, beetles, caterpillars, leafhoppers, bees, and ants in sizes 10-18 are tops.
All of these surface flies require 10-14 foot leaders, tippets of 4-7X, and delicate presentations. The only exception would be the larger land insects—big beetles, hoppers, and crickets—which sometimes work better when they are dropped next to fish near the bank with a “plopping” sound to draw the fish’s attention to the fly. This realistic impression of an insect falling in from streamside vegetation is often more than a hungry tailwater trout can resist.
A few tailwaters have a constant flow and some fluctuate slightly. Many of these rivers, however, rise violently when the dam gates are opened. On those rivers, always be aware of any changes in water level.
Try to call ahead and find out when releases are likely to come. And always head to shore immediately if the water starts to rise. Wearing a flotation vest and using a wading staff are also good safety practices on tailwater rivers.
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