In this report
79 CFS: Below the Sweet Spot, But Still Fishable—If You Fish Smart
The gauge is reading 79 CFS this week, and that puts us firmly in the low-end territory for Eleven Mile. Your reference range on this water runs 50–150 CFS for typical conditions, with the real sweet spot sitting around 150–250 CFS for dry-fly work. We’re well below that, and that fact should shape how you fish every pocket and pool this week.
Here’s what 79 CFS means in the real world down the canyon: the water is thin. The roily pocket water that usually breaks fish loose from the main current is shallow and fast, fish are concentrated hard into the deeper slots and behind structure, and your wading margin is tighter. The holding water hasn’t disappeared—it’s just compressed. Worse, at this flow the shallow margins warm faster under afternoon sun, and a tailwater this low is always worth a water-temperature check before you commit to a full day. If you’re fishing, start early, stay mobile between the cooler pools, and don’t linger in the skinny water at midday.
The flip side: 79 CFS makes fish spooky. In thin water, they see you, feel your footsteps, and notice a sloppy cast. You’ll need longer leaders, a lighter touch on the line, and patience. It’s not impossible—plenty of anglers have excellent days on Eleven Mile at low flow—but it requires discipline instead of power-fishing.
Midges and Tricos: The Core Menu, Morning and Evening
August here is midge season first, always. Black Beauty and Mercury Midge patterns in #20–24 will be your workhorses all week, fished as emergers in the film and stripped slowly near the bottom of the deeper holds. At 79 CFS, depth is your friend; use a #20–22 midge emerger on the point, weighted, and fish it tight to the substrate in the pools. The water’s moving slowly enough that you won’t need heavy shot, but you’ll need to feel the bottom.
Trico spinner falls are showing up in the early mornings—#20–24 spinners in dark gray or black. These are real, and they’ll draw surface-feeding fish when the light is low and the air is cool. If you’re down there at dawn, have a small spinner pattern ready, but don’t wait all day for the hatch to repeat. A single midge nymph rig fished subsurface will outproduce searching for spinners by 9 a.m.
Caddis in the evenings are also live, but “evening” on Eleven Mile in early August means 6 p.m. onward, when the canyon shadows cool the air. Small tan or olive caddis dries in #14–16 can work, but the light fades fast in the canyon, so your window is short. Don’t camp on caddis expecting a bonanza; it’s a bonus if conditions align, not the anchor.
Terrestrials—ants, small beetles, and hoppers—matter more than you’d expect on a tailwater this time of year. When the afternoon heats up, try a small black ant (#18–20) or a tiny hoppper (#12–14) drifted in the shallower, warmer margins and edges. Fish them without weight, dead-drift or with a twitch. At 79 CFS, terrestrials often outperform midges when the sun is high, because the fish are looking up and the margins are more accessible.
The Rig That Works This Week
Build your confidence around a two-fly nymph setup:
Point fly: A #20–22 Mercury Midge or Black Beauty, weighted (tungsten bead or a wrap or two of wire). This is your anchor, your depth finder, and your primary offering.
Dropper: A #18–20 PMD emerger or a lighter midge pattern (Zebra, RS2), tied 16–20 inches above the point with a 3x or 4x tag of tippet. At low flow and with spooky fish, the dropper gives you a second chance without adding bulk.
Tippet: Use 5x for the main leader (8–9 feet total), then 4x for the dropper connection and point-fly connection. 5x gives you the lightness you need for visibility in clear water; 4x on the point lets you fish a weighted midge without constant breakoffs on the strike or on the bottom.
Weight: Split shot is your friend here, not tungsten putty. Place one micro split shot 12–14 inches above the point fly. This keeps the rig responsive and lets you adjust depth in seconds as you move between water types.
Indicator or tight-line: At 79 CFS, a small foam indicator works fine if you’re fishing deeper pools (2–4 feet). If you’re working pocket water or running shallower slots, tight-line nymphing (no indicator, fishing by feel and a slight belly in the line) is more effective. You’ll detect takes better, spook fewer fish, and keep your rig lighter. Pick the method based on the water in front of you, not habit.
Where to Spend Your Time
The 3.8-mile quality-water stretch offers different personalities mile to mile. At 79 CFS, focus on the deeper pools and the slots immediately below pocket water, where current breaks have carved out 3–5 feet of depth. Fish those hard. The roily white-water sections that usually hold eager feeders are too thin right now—the fish have moved deeper and tighter.
The slower, wider pool sections with overhanging vegetation or deadfall are gold. These are the places where fish have refuge from the bright midday light and the spooky conditions. Work them carefully, lengthening your cast and waiting longer for the drift to develop. In thin water, patience often out-fishes aggression.
Avoid the margins and tail-outs at midday. At low flow and warm air, those shallows push toward uncomfortable temperatures quickly. Save them for dawn or late afternoon.
Access, Fee, and a Water-Temperature Note
Remember: the $11 day-use entrance fee at the gate covers access to the canyon. An annual Colorado State Parks pass does not cover this—it’s a U.S. Forest Service fee, separate from the reservoir area above the dam. Bring cash or a card; the station is at the entrance.
The canyon road hugs the river closely, so parking and foot access are easy at pullouts all along the 3.8-mile stretch. That’s one of Eleven Mile’s best qualities—no long hikes required.
Water temps: Check before you fish. At 79 CFS in early August, the tailwater coming from the reservoir’s depths is likely cool—probably in the low to mid 60s—but thin water warms faster than full flows. If you see temps creeping above 68°F during the day, fish early and late, and keep your sessions short in the afternoon. Handle fish gently; they’re stressed enough.
This week is small-fly, deep-water, careful-footwork fishing. If that appeals to you, Eleven Mile will reward you. If you’re looking for rip-roaring surface action and headlong wading, wait for higher flows.