In this report
Flow is Dropping—Fish the Holding Water While You Can
At 143 CFS, Deckers is running lean. That’s below the ideal 150–400 range for this water, and it matters more than you might think on a freestone reach like this. The South Platte here doesn’t have the modulating influence of a dam outlet to buffer low-water stress; what you see is what you get, driven by mountain snowmelt and summer evaporation. At this level, the river has lost some of its cushion.
What does that mean on the ground? The riffles and current tongues that usually hold feeding fish are tighter, shallower, and faster—good news for visibility but bad news for comfort. Fish are concentrated into deeper slots and the slower seams behind rocks where they can rest without burning energy in thin water. The bright afternoon light and low volume make them skittish; a sloppy wade or a shadow across the water will send them down. Temperature is also a concern this week. August is peak heat season, and low flow means less water cycling, which means warmer water. The Platte warms fast in direct sun, especially in the open sections around Deckers where you don’t have canyon shade. Fish welfare matters—if the water climbs much above 65°F, consider moving to shade or saving your time for early morning and evening.
Tricos in the Morning, Then Shift to Soft Hackles and Ants
The primary hatch right now is the Trico spinner fall. It happens early—typically 7:30 to 9:00 a.m. on cool mornings, earlier if it’s hot—and it’s a tight window. You’ll see small dark spinners (males and females, #20–24) coming down in the current, often in a concentrated pulse. On low, clear water, this is when Deckers fishes best. Fish are feeding with confidence and surface activity is visible. A #20 or #22 Trico spinner in a traditional profile (dark body, spent wings) is your primary. Fish it drag-free in the slower seams and behind rocks where the current brings naturals. A long, fine leader (9 feet, 5X or 6X tippet) is non-negotiable this week—the water is too clear and the fish too concentrated to forgive heavy tippet.
Once the Trico fall is done (by mid-morning), subsurface fishing takes over. Midges remain the year-round staple on this reach. Rig a #22 RS2 emerger or Mercury Midge as your point fly, 18 inches below a small split shot, and fish it tight to the bottom in the deeper runs and slots. You won’t see a ton of flash—this is technical, nymph-and-indicator or tight-line work. A small yarn indicator or a delicate buoy will help you detect takes; if you’re tight-lining, feel is everything. Cast upstream and let the fly dead-drift through the run. In low water, the slots behind mid-stream rocks and the inside bends of the slower stretches are your bread and butter.
By afternoon, terrestrials take a role. August heat means ants and beetles are active. Carry a small #14 or #16 black ant and a #16 cinnamon beetle. Fish them dry or as a hopper-dropper combo—a #14 ant or beetle on top with an 18-inch dropper of that same #22 RS2 emerger below. This works especially well in the late-day window (4 to 6 p.m.) when fish are a touch less spooky and still willing to rise. The ant or beetle acts as an indicator and a searching fly; the emerger below guarantees you’re also working the subsurface film where a lot of fish are feeding during the heat of the day.
Rig for Low Water and Spooky Fish
Your leader and tippet this week are critical. Go long and light: 9 feet of leader, stepping down to 5X or 6X for everything except your terrestrial searching patterns (where 4X is reasonable). The clear water and low flow amplify your mistakes.
For the Trico spinner morning, fish nothing but a dry—#20 or #22 spinner on 5X or 6X. No dropper. Keep your cast short (20 to 30 feet) and accurate; a drag-free drift is the whole game.
For subsurface work, here’s a rig that works: tie your indicator 4 to 5 feet above your point fly. Use a small split shot (a BB or smaller) 12 inches above the point fly, not directly above it—this keeps the fly moving naturally and reduces tangles on the cast. Your point fly is the RS2 or Mercury Midge (#22). If you want to add a dropper, tie it 8 inches above the point fly using a surgeon’s knot or a loop-to-loop connection. A #16 or #18 soft-hackle (olive or tan) works well as a dropper; it’s more mobile than a small nymph and moves water to hint to the fish that something is alive. Tight-line fishing also works here, especially if you’re comfortable reading subsurface takes. Use a dry fly (a small hopper or ant) as your contact point, and let a small nymph dangle 18 inches below on 6X tippet.
Where to Fish on Low Water
On the roadside stretches near Deckers Bridge, Trumbull, and Scraggy View, focus on the deeper runs—the slots where the river slows and deepens after a riffle. These hold concentrated fish in low flow. Work the inside bends where current speed drops; fish hold on the edges of faster water, not in the middle of it at this level. Behind mid-stream rocks, especially larger boulders, the water speed drops enough to give fish a rest, and that’s where they’ll be sitting and feeding subsurface.
Avoid the shallow, fast riffles unless there’s obvious Trico activity. In low, clear water, you’ll spook more than you’ll catch in thin, bright water. Save your energy for the deeper seams and the shade.
Two Reminders for This Week
First: water temperature. If you’re fishing midday and the water feels warm (above 65°F), you’re helping fish stress. Fish early and late. Consider catch-and-release or moving to shade. Low flow + August heat is a welfare issue, not just a technical one.
Second: verify current regulations before you fish. The 2 trout over 16 inches rule and flies-and-lures-only regs apply here at Deckers, but regulations change year to year. A quick check before you drive down CO-67 saves time and keeps you legal.
The next few days will likely stay clear and low. Fish early, fish light, and respect the water’s current mood.