Tailwater · Mixed · Colorado, US

South Platte — Eleven Mile Canyon

South Platte — Eleven Mile Canyon — South Platte River Eleven Mile Canyon scouting

Eleven Mile Canyon is the reach below the reservoir, a granite-walled tailwater you can drive right alongside, which makes it popular and pretty in equal measure.

Today · About as good as it gets
Czech Nymph
Forecast · Today
About as good as it gets
On the feed top to bottom — start on the rises with a dry, drop a nymph if they stay down.
90% projected
Today's fly
Czech Nymph
Czech Nymph
Conditions on the water · Today
Estimate
Level
Dry recently
No gauge reading
Water temp11.5°C
ClarityClear
Weather16°C
WindN 8 km/h
Pressure1019 hPa
Rain · recent1.2 mm
Rain · ahead0.2 mm

No gauge on this water — readings are regional estimates from weather, not a live gauge.

Water temperature for Brown Trout
Ideal
12°C est.ideal 10–16°C
0°14°28°
How to fish it · for Brown Trout
When
Nymphing can work through most of the day.
Where
Cover mixed depths.
Method
Start with tight-line nymphs and adjust if fish rise or drift higher.
Kit
9 ft #4 rod, floating line, 12 ft tapered leader to 4–5 lb fluoro tippet.
Why this works
Excellent — water temperature is right today, though insect activity could be better.
Likely species
Mayflies
Caddisflies
Hatch timeline · todayPeak at 11am

12pm(now) — Western Blue-Winged Olive

Stage: On emergersApproach: Emerger or dryActivity: 86%
Also:Black Midge51%
Peak emergence window8 food groups active

Peak activity at 11am — Western Blue-Winged Olive (Western Blue-Winged Olive, Peak emergence window)

Sub-surface · on the nymphunder the surface

Hatch predictions

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Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Top prey shown — see all 4 with Pro.

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Evidence
Records-basedModerate confidence

Based on species-occurrence records, not local invertebrate surveys.

Through the year
0–3 scale · September highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
2
2
2
2
2
1
Western Blue-Winged OliveHatch
2
3
3
3
3
3
3
3
2
Pale Morning DunHatch
2
3
3
2
TricoHatch
2
3
2
Black MidgeHatch
2
3
3
3
3
3
3
3
3
3
3
2

Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.

Ranked for today
Brown Trout fly box
Permits & access
Permit required — see local rules.
  • Colorado licence
  • Gold Medal / special-regulation sections — verify CPW rules
  • Canyon road access (fee area).
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
South Platte — Dream Stream (Spinney to Eleven Mile)
17 km
Rainbow trout · Brown trout
South Platte — Cheesman Canyon
37 km
0
Rainbow trout · Brown trout
South Platte — Deckers
45 km
Rainbow trout · Brown trout
Arkansas River — Bighorn Sheep & Royal Gorge (Cotopaxi to Parkdale)
51 km
30
Brown trout · Rainbow trout
Arkansas River — Browns Canyon (Buena Vista to Salida)
57 km
30
Brown trout · Rainbow trout
Gallery · 2
  1. South Platte — Eleven Mile Canyon — South Platte River Eleven Mile Canyon scouting
    South Platte River Eleven Mile Canyon scouting
  2. Terrain map of the venue
    Terrain map
About this water

Eleven Mile Canyon is the reach below the reservoir, a granite-walled tailwater you can drive right alongside, which makes it popular and pretty in equal measure. Browns and rainbows hold in the pocket water and the slow glides, and it fishes well in the cold months when the high country is locked up. It's more forgiving and more scenic than the Dream Stream above it, and it shares the same essential logic: watch what comes out of the dam, fish small, and expect company near the easy pullouts.

  • Mixed
Water quality · US Clean Water Act
  • Aquatic life: Supporting
What this classification means

EPA ATTAINS assessment unit 'South Platte River, all tributaries.' (COSPUS02a_E), 2024 Integrated Report. Aquatic Life use: Fully Supporting. This is a Clean Water Act assessment-unit classification (the US analogue of WFD), not a live reading.

Status is for the Clean Water Act assessment unit covering this reach.

EPA ATTAINS (Clean Water Act) · COSPUS02a_E

The full read · show the working · for Brown Trout · confidence 90%
How the 84 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time65 × 13%8.5
Pressure80 × 7%5.6
Insect activity62 × 12%7.4
Conditions total= 84
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
What would change the calculation
The dawn and dusk windows score higher than the midday lull.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout 1 January → 31 December
Related guides
Euro Nymphingsubsurface methods
Casting instructors near here
Booking & contacts