In this report
Water’s Running Low—Fish It Tight and Small
The gauge is sitting at 83 CFS, and that’s the story this week. For Deckers, where you want to see 150–400 CFS flowing over the riffles and runs, 83 is notably low and clear. This isn’t an emergency—the water is still fishable and cold enough that trout won’t suffer—but it does change how the river behaves and how you need to approach it.
Low, gin-clear water concentrates fish into the deeper slots and behind any structure that breaks current. The long, open runs that work fine at 200 CFS become shallow and fast relative to where the trout want to hold. Wading gets easier—you can cross more of the roadside reaches without drama—but visibility works against you. Fish see you coming farther away and spook harder. The margins matter more than they do at fuller flows; a trout sitting in 18 inches of water against the far bank can bolt the moment your shadow crosses it or you wade into the window.
Cold air the past few days has kept water temperature in the low 50s, which is good news for fish welfare and good for stability, but it also means trout are less active than they might be at the start of the month. They’re not feeding with urgency. They’re holding tight and eating what drifts to them, not roaming.
Midges and Small Blue-Wings: The Real Pattern Right Now
October on the South Platte freestone means two things: the last strong pulses of Blue-Winged Olives on gray and cloudy days, and midges. The Tricos are done. BWOs are showing in the #20–22 range on overcast mornings—small dries that require a careful presentation and fine tippet. But in a week where the water is running low and clear, don’t spend all your time chasing surface activity that may never materialize. Midges are the safer bet and the more consistent producer right now.
Fish the subsurface midges: #20–24 emergers and pupae. Black Beauty, Mercury Midge, zebra midge, RS2s—the standbys that work all year on this water. At 83 CFS, the profile is clearer and the fish are spookier, so smaller is actually an advantage. A #22 midge emerger looks more natural and less like a rig you’re dragging through the water column than a #20 PMD nymph would.
If the sun breaks and you see BWO dries working (look for risers in the slightly slower water along the willows or in the bubble lines), switch to a #20 or #22 olive parachute or CDC pattern. But keep a midge dropper on. The odds are high that for every dry take you miss, you’ll have better luck with a #22 emerger or a small RS2 hanging 18 inches below.
How to Rig and Fish at This Flow
Split-shot and an indicator. This isn’t a time to get fancy with tight-line nymphing, though if you’re comfortable with it, go ahead—the low water and calm conditions favor precision. But for most of the week, an indicator setup will let you cover more ground and hold the flies in the zone longer without constant mending.
Use a heavy anchor—a #16 Barr’s-style wrap (Copper John, Juju Baetis, or plain lead-wrap body nymph) on the point. Tie your #22 midge emerger 18 inches above it on a short dropper (2X tippet, 6 inches off the main line). Add split shot 12 inches above the dropper—one or two small shot, depending on depth. The goal is to tick the bottom of the deeper slots and runs without dragging; you’re not trying to dredge.
Use 5X tippet for the point fly if you’re confident in your knot work; 4X is safer and still fine for trout in the 10–14-inch range that Deckers typically offers. The main line can be 3X or 4X. At 83 CFS, you’re fishing short casts—35 to 50 feet—to keep control and let the indicator sit cleanly. Longer casts and the indicator will drag, and you’ll miss eats.
Where to Spend Your Time
Skip the flat, open glides that stretch 80 feet from bank to bank at lower flows. They’re not holding much right now. Focus on the deeper riffles and the runs where you can see a distinct current tongue or a slot running 3 to 5 feet deep. These pockets hold fish at 83 CFS because they’re the only places cold enough and deep enough to feel comfortable.
Fish the near bank carefully, working short casts and letting the rig sit for a count of two before moving. Trout will be tight to the bank, in the shade of the willows, or tucked in small indentations where they can see drifting food without having to move far. Wade slowly and deliberately, and don’t false-cast more than once over a likely hold—low water means more visibility, and the fish will see your line.
The roadside access along CO-67 makes this easier than it sounds. You can park at Deckers Bridge or Trumbull and work the riffles and runs within sight of the road without hiking far. At 83 CFS, even the shallow margins have edges that hold fish if you work them carefully.
A Stewardship Note
Low flows mean warmer water (even at 50 degrees, it’s warming faster than it would at 250 CFS) and more handling stress on the trout. Keep your time on the water focused: fish the likeliest water, land fish quickly, and release them gently. If you’re planning to keep a couple for the table—remember, the regs allow 2 trout over 16 inches—be selective and keep the largest ones. Letting smaller fish back in the water means less stress on the population.
Verify current regulations before you go; regs can shift year to year.