Spate · Granite · Brittany / Côtes-d'Armor, FR

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.

Today · Closed season
Black Gnat
New ruleReported 14 Aug 2026

Severe drought restrictions (crise) in force

VigiEau lists this venue's surface-water zone (Zone ouest, dépt 22) at crise, under an official préfectoral drought arrêté. Fishing is not itself banned by it, but water levels are low — go gently on stressed fish.

Arrêté préfectoral n°37718 ↗

Temporary notices from official orders and recent fishery reports — they clear automatically once out of date.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

Forecast · Today
Closed season
Out of season. Try elsewhere.
45% projected
Today's fly
Black Gnat
Black Gnat
Conditions on the water · Today
Live gauge
Level
Rising
0.14 m
Lifting fast
Water temp17.0°C
ClarityUnfishable
Weather18°C
WindN 25 km/h
Pressure1013 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
17°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.
Hatch timeline · todayPeak at 12pm

12pm(now) — Heather Fly

Stage: Terrestrials on topApproach: Dry flyActivity: 53%
Also:Reed Smut45%Cinnamon Sedge23%
Peak emergence window9 food groups active

Peak activity at 12pm — Heather Fly (Heather Fly, Peak emergence window)

Sub-surface · on the nymphunder the surface

Hatch predictions

Supporters see the full sub-surface read.

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Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Top prey shown — see all 2 as a supporter.

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Evidence
Survey-backed · regionalHigh confidence

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

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
1
March BrownHatch
2
3
2
Late March BrownHatch
2
3
2
Large Brook DunHatch
2
3
2
Large StoneflyHatch
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
Other water nearby · 2
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 0 is built — score × weight = contribution
Temperature70 × 28%19.6
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time80 × 13%10.4
Pressure80 × 7%5.6
Insect activity59 × 12%7.1
Conditions total= 77
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitysurvey-backed invertebrate datasurvey
Directions
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
Booking & contacts