Spate · Granite · Brittany / Côtes-d'Armor

Trieux

A wide panoramic view of the wooded Trieux river valley with the tidal river visible below.

Small Brittany stream with wild trout on Armorican granite.

Poor · Brown Trout
CDC Emerger · 16-18
New ruleReported 3 Aug 2026

Severe drought restrictions (alerte renforcée) in force

The Zone ouest zone (Dept 22) is at alerte renforcée — the second-highest French drought tier — under a préfectoral arrêté. Fishing itself is not named as prohibited, but water is severely restricted and flows are likely very low; fish with care and check locally.

Arrêté préfectoral n°37573 ↗

Temporary notices from official orders and recent fishery reports — they clear automatically once out of date. Always confirm locally before travelling.

Poorlive now
Not the day for it
River temperature is the limiting factor today, not the flow. This is not the day to push it. Check the thermal advice above before you head out.
90% confidence
What moved it
  • Level0.13 mLast reading 12h ago
  • Water temp22.1°C
  • ClarityClear
Today's fly
CDC Emerger
CDC Emerger16-18
Dead-drift
Conditions on the water
Live gauge
Level
Steady
0.13 m
Last reading 12h ago
Water temp22.1°C
ClarityClear
Weather28°C
WindNW 11 km/h
Pressure1021 hPa
Rain · recent0.0 mm
Rain · ahead0.0 mm

The nearest gauge doesn't record temperatures, so we've estimated it — defer to the river keeper's advice.

Water temperature for Brown Trout
Warm — slow
22°C est.ideal 10–16°C
0°14°28°
How to fish it · for Brown Trout
When
Through the open trout season. Spring olives and grannom; sedges through summer evenings; small dark flies into autumn close.
Where
Pool tails and the seams behind boulders through the Côtes-d'Armor stretches. Breton spate freestone — fish 12 to 24 hours after rain. The Trieux is a typical Côtes-d'Armor spate — short, sharp, wadeable.
Method
Upstream dry to risers; dry-dropper through the riffles. Breton spate freestone — fish 12 to 24 hours after rain on the drop. Long leader, fine tippet.
Kit
9 ft #4 — Breton spate freestone. Floating line, 12 ft leader to 4 lb fluoro. Studded boots.
Why this works
Water at 22.1°C. This is the line where catch-and-release kills brown trout. Do not fish for them today.
Hatch timeline · todayPeak at 6pm

Hatch predictions

Today's headline hatch shown — see all 7 active hatches hour by hour with Pro.

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Sub-surface · on the nymphunder the surface

Hatch predictions

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Beyond the hatch · worth watchingambient prey

Hatch predictions

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Evidence
Survey-backed · regionalModerate confidence

Backed by regional invertebrate surveys; no sampling on this exact reach yet.

Through the year
0–3 scale · August highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
1
March BrownHatch
2
3
2
GrannomHatch
2
2
Large StoneflyHatch
2
3
2
Yellow SallyHatch
2
3
2

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

Ranked for today
Brown Trout fly box

More balanced than the mountain-river pack. French nymphing still matters, but there is more room for dries, spiders and general searching flies.

Permits & access
Permit required — see local rules.
  • AAPPMA permits.
What's coming
Plan ahead
5-day outlook
Water here around 22°C. Nothing cooler within range — carry a thermometer.
Gallery · 2
  1. A wide panoramic view of the wooded Trieux river valley with the tidal river visible below.
    View over Trieux River from La Roche-Jagu Chateau
  2. Terrain map of the venue
    Terrain map
About this water

Small Brittany stream with wild trout on Armorican granite. Fly-fishing potential for those willing to seek out intimate water. Spring through early autumn. Not crowded — solitude and wild trout are part of the appeal. Check local AAPPMA for access details and any seasonal restrictions.

Hatches & food

On Atlantic trout rivers in Normandy and Brittany, regional studies and on-the-bank experience point to spring mayflies as the main early driver, a strong band of spring and early-summer caddis as channels warm and open, background buzzer life ticking away right through the year, and terrestrials from wooded banks adding important surface food in summer and early autumn, with autumn olives extending sport wherever trout-season rules allow.

  • Granite
Water quality (WFD)
  • Ecology: Moderate
  • Chemical: Unknown

WFD classification · FRGR0030B

The full read · show the working · for Brown Trout · confidence 90%
How the 12 is built — score × weight = contribution
Temperature6 × 28%1.7
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time65 × 13%8.5
Pressure80 × 7%5.6
Insect activity54 × 12%6.5
Limiting factor: Water temperature (22.1°C) is outside Brown Trout's preferred range (10–16°C)= 57
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitysurvey-backed invertebrate datasurvey
What would change the calculation
Cooler water — back toward the 10–16 °C ideal band — would lift the score and ease welfare.
The dawn and dusk windows score higher than the midday lull.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout 2nd Saturday of March → 3rd Sunday of September

Salmon: Banned (2026) — Brittany 2026 order bans Atlantic salmon and sea trout on all Breton rivers.

Sea trout: Banned (2026) — Brittany 2026 order bans Atlantic salmon and sea trout on all Breton rivers.

Related guides
Pyrenees PlaybookFrench riversEuro Nymphingsubsurface methods
Booking & contacts