Freestone · Limestone · Catalonia, ES

Upper Segre

Upper Segre terrain map

The upper Segre above La Seu d'Urgell is a limestone river rising in high Pyrenees near Andorra and flowing southeast through mountain valleys and gorges.

Marginal · Brown Trout
Perdigón · 14-18
Marginallive now
Slow going — pick your moments
River temperature is the limiting factor today, not the flow. Fish dawn or dusk if you go at all, and handle everything with extra care.
80% confidence
What moved it
  • LevelProxyvia Noguera Pallaresa
  • Water temp19.9°C
  • ClarityClear
Today's fly
Perdigón
Perdigón14-18
High-confidence seasonal pick
Conditions on the water
Proxy gauge
Level
Falling
Proxy
via Noguera Pallaresa
Water temp19.9°C
ClarityClear
Weather26°C
WindNE 9 km/h
Pressure1018 hPa
Rain · recent0.0 mm
Rain · ahead1.7 mm

No gauge on this water — conditions are inferred from Noguera Pallaresa. The trend transfers, the absolute level does not.

Water temperature for Brown Trout
Warm — slow
20°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
Water at 19.9°C — above the brown trout caution line (18°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots.
Hatch timeline · todayPeak at 6pm

Hatch predictions

Today's headline hatch shown — see all 10 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 · regionalHigh 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
GrannomHatch
2
2
Evening SedgeHatch
2
3
3
3
2
Large Dark OliveHatch
1
2
2
1
Iron BlueHatch
1
2
2
1

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.
  • Catalan fishing licence required
  • Controlled trout waters may require a ZPC permit, and legal dates differ between low-mountain, high-mountain, with-kill, and no-kill sectors, so check the current Generalitat rules for the exact zone.
What's coming
Plan ahead
5-day outlook
Cooler water nearby · 1
Water here around 20°C — probably warm enough to stress Brown Trout . These are likely cooler.
Noguera de Cardós
19 km
~15°C
Brown trout
About this water

The upper Segre above La Seu d'Urgell is a limestone river rising in high Pyrenees near Andorra and flowing southeast through mountain valleys and gorges. Clear, alkaline freestone holds excellent wild brown trout with high biodiversity. Technical runs alternate with pocket water and pools throughout. The Segre's upper reaches — Organyà, Montferrer, La Seu d'Urgell zones — are the true trout destination. Good dry-fly and nymphing opportunities throughout.

  • Limestone
Water quality (WFD)
  • Ecology: Good
  • Chemical: Unknown

WFD classification · ES091MSPF621

The full read · show the working · for Brown Trout · confidence 80%
How the 28 is built — score × weight = contribution
Temperature26 × 28%7.3
Flow95 × 22%20.9
Clarity95 × 18%17.1
Feeding Time55 × 13%7.2
Pressure80 × 7%5.6
Insect activity65 × 12%7.8
Conditions total= 66
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via Noguera Pallaresaproxy
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 depends on Catalan zone class → depends on Catalan zone class
Related guides
Pyrenees PlaybookSpanish riversEuro Nymphingsubsurface methods
Booking & contacts