In this report
107 CFS and 57°F: Early-Fall Stability Before the Volatility
At 107 CFS and 57°F, the Pueblo tailwater is sitting in a genuinely comfortable window—one that won’t last. This is the sweet spot between summer’s heating risk and the unpredictable swings that define this water’s character. The flow is lean but stable, the water is cool enough that trout are holding in their normal October lies instead of compressed into the deepest slots, and wading is straightforward across most of the productive water. The catch: the dam-release schedule that makes this tailwater famous for its volatility hasn’t forgotten you. Check the flow chart before you drive down. A 30 or 40 CFS swing isn’t dramatic for other Colorado tailwaters, but it fundamentally changes how the Pueblo water fishes—concentration, spookiness, and which holding water comes into play all shift fast.
Right now, you’re in a window where a deliberate approach to morning and midday fishing will reward you. Don’t coast on it.
Midges Rule; BWOs Appear on Clouds
October here runs on two principal hatches: midges (the year-round backbone of the Pueblo tailwater) and fall BWOs when the sky turns gray and the air cools. Neither is a blitz, but both are reliable enough to anchor a day.
Midges are your primary target. At this flow and temperature, midge nymphs are the foundational fly—#20–22 patterns in black, gray, and olive, fished as deep emergers or as the anchor in a two-fly rig. Barr’s Bloody Mary, RS2 emergers, and Mercury Midges all work. The emerge-and-suspend phase is where most fish come up, so have a handful of #20–22 midge pupae tied on light wire or even standard wire; the goal is to let them hang in the zone for a beat or two before they drift past.
Fall BWOs come in at #20–22—smaller than summer versions and grayer in coloration. On overcast days or when the light softens, especially late morning through afternoon, watch for a slow rise of very small mayflies. This water doesn’t produce dramatic BWO emergences, but it does produce consistent small-fly feeding, and trout will rise to emergers if the activity is steady. Tie a few small olives, grays, or rusty-olive parachute or thorax dries in #20–22 and have nymph versions of the same in your box.
Tricos are done. Browns are beginning pre-spawn movements deeper and toward structure, which matters if you’re swinging streamers, but the main-column fishing is still the bread and butter.
How to Fish 107 CFS This Week
At this flow, the productive water is more concentrated than it is in summer, but it’s not squeezed yet. You can work the deeper slots, the inside bends, and the tail-out seams with confidence. Wading is easy—you’re not fighting current or scrambling over boulder fields.
Primary rig: Start with a #20 midge nymph (Barr’s Bloody Mary or RS2 emerger) as your point fly, 18 to 24 inches below a strike indicator. Add a #22 midge pupa or small olive BWO nymph as a dropper about 12 inches above the point. Use 6X fluorocarbon tippet for both—fine enough to let the small nymphs drift naturally, stout enough to handle the occasional brown trout that still has autumn aggression in its system.
Split-shot placement matters more at this flow than it does at higher water. A single split-shot (small or medium) pinched on your tippet about 8 to 10 inches above the dropper will get you to the bottom of the deeper channels without dragging the bottom constantly. The goal is a dead-drift that ticks occasionally—not a plow.
Water to target:
- Deep inside bends where current has scoured a run. This is where trout hold when the flow is steady and cool. Work the indicator so the flies drift through the heavy part of the seam.
- Tail-outs of pools and deeper riffles, especially where water transitions from fast to slow. Trout position at the edge of the current break.
- The seam behind midstream rocks and boulders. At 107 CFS, these don’t create huge dead zones, but they create cushion where a trout can rest and intercept drifting food without fighting the main current.
Skip the thin, sunlit flats unless you see actual rising fish. At this flow and light, the shallow water doesn’t hold many fish—they’re in the meaty current or the deeper pockets.
Drift technique: Cast across and slightly upstream, set the indicator so the flies are 2 to 3 feet deep (adjust based on water depth), and maintain a tight line to the indicator. Watch for the slightest hesitation or dip. Strikes can be savage or barely perceptible; don’t wait for a confirmed tug. Set at any doubt.
If you’re not getting takes on nymphs after two or three productive-looking drifts, tie on a small midge dry—#20–22, black or gray—and fish it alone in a riffle or tail-out where you’ve seen activity. Let it sit and drift naturally. The takes can be tiny; watch the fly, not the end of your line.
Water Temperature and Stewardship
57°F is genuinely safe water right now. You can fish confidently through midday. That said, the Pueblo tailwater’s biggest draw is its winter fishery, and we’re only a month away from when stable, cold flow makes this water exceptional. Don’t take that for granted now. If flows spike upward to several hundred CFS over the next week or two as demand on the reservoir changes, water temperature will climb temporarily. Carry a thermometer. If you’re seeing numbers creeping into the mid-60s, stick to early morning and evening, and focus your effort on the deeper, shadier water—the slots below the dam and the deeper inside bends, not the flats.
The special regulations on the upper stretch closest to Pueblo Dam are strict—verify the current bag limit and fly-only zone before you fish that section. If you’re targeting big browns, you’ll want to know exactly where catch-and-release applies and where it doesn’t.
Get on the water early this week. The stability won’t last forever.