Freestone · Mixed · Pyrénées-Orientales / Cerdagne, FR

Segre (Cerdagne)

Segre (Cerdagne) terrain map

Catalan mountain stream flowing from the Cerdagne plateau.

Good · Brown Trout
CDC Emerger · 16-18
Goodlive now
A proper day on the water
Low and clear — careful approach country. Stay small, stay accurate.
90% confidence
What moved it
  • Level0.31 mLast reading 6h ago
  • Water temp17.4°C
  • ClarityClear
Today's fly
CDC Emerger
CDC Emerger16-18
Dead-drift
Conditions on the water
Live gauge
Level
Steady
0.31 m
Last reading 6h ago
Water temp17.4°C
ClarityClear
Weather18°C
WindSW 10 km/h
Pressure1020 hPa
Rain · recent0.3 mm
Rain · ahead7.7 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
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
Good — water clarity is right today, though time of day could be better.
Hatch timeline · todayPeak at 6pm

Hatch predictions

Today's headline hatch shown — see all 11 active hatches hour by hour with Pro.

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Sub-surface · on the nymphunder the surface

Hatch predictions

Top nymph shown — see all 3 guilds with Pro.

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Beyond the hatch · worth watchingambient prey

Hatch predictions

Top prey shown — see all 2 with Pro.

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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
Grayling seasonSeason
1
2
2
2
1
GrannomHatch
2
2
Evening SedgeHatch
2
3
3
3
2
Alpine RhithrogenaHatch
1
2
2
1
Large Dark OliveHatch
1
2
2
1

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.
  • Shared French–Spanish border river
  • French AAPPMA permits required on French section.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Bouillouses Mountain Lakes
21 km
Brown trout
Llobregat
25 km
Brown trout
Freser
27 km
Brown trout
Catalan Pyrenees controlled zones
27 km
17
Brown trout
Upper Segre
29 km
28
Brown trout
About this water

Catalan mountain stream flowing from the Cerdagne plateau. Freestone with wild trout and grayling in cold, clear water. Short season — snowmelt-dependent. Fish from June onward when water clears and warms. High altitude, technical pocket water. Hiking-in country; expect pristine conditions and few anglers. Check regional regulations for protected stretches.

Hatches & food

In the Pyrenean gaves and headwater torrents, resident brown trout move from early-season olives and March browns into strong spring and early-summer stonefly activity, then a long spell of evening caddis and small buzzers, with terrestrials most relevant on wooded lower gaves and much less important high above the tree line.

  • Mixed
Water quality (WFD)
  • Ecology: Moderate
  • Chemical: Unknown
What this classification means

WFD ecological status Good → Moderate corrected to EEA WISE 2022 (3rd RBMP) classification for waterbody FRDR11149 (was a stale earlier-cycle value). Source: EEA WISE SWB_SurfaceWaterBody (discodata.eea.europa.eu), verified 2026-06-18.

WFD classification · FRDR11149

The full read · show the working · for Brown Trout · confidence 90%
How the 75 is built — score × weight = contribution
Temperature68 × 28%19.0
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time60 × 13%7.8
Pressure80 × 7%5.6
Insect activity65 × 12%7.8
Conditions total= 75
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
  • Grayling 3rd Saturday of May → 3rd Sunday of September

    France national rule: grayling opens 3rd Saturday of May in all waters. In 1st category (salmonid) rivers, grayling closes with the trout season on the 3rd Sunday of September. Departmental regulations may impose additional restrictions. Always check the relevant département's 2026 arrêté préfectoral.

Related guides
Grayling Playbookgrayling tacticsPyrenees PlaybookFrench riversEuro Nymphingsubsurface methods
Booking & contacts