Freestone · Mixed · Pyrénées-Atlantiques, FR

Gave d'Ossau

A wide clear river with turquoise water flowing over gravel past a forested limestone ridge in the Pyrenees

The Gave d'Ossau is upper Béarn — snowmelt-fed Pyrenean freestone dropping out of the Pic du Midi country and running north through the valley towards Oloron, where it feeds the bigger Gave system.

Today · Closed season
Coch-y-bonddu
New ruleReported 7 Aug 2026

Severe drought restrictions (alerte renforcée) in force

VigiEau lists this venue's surface-water zone (Bassin du Gave d'Oloron, dépt 64) at alerte renforcée, 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°37628 ↗

Temporary notices from official orders and recent fishery reports — they clear automatically once out of date.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.
80% projected
Today's fly
Coch-y-bonddu
Coch-y-bonddu
Conditions on the water · Today
Live gauge
Level
Rising
0.08 m
Lifting fast
Water temp19.0°C
ClarityUnfishable
Weather23°C
WindN 8 km/h
Pressure1018 hPa
Rain · recent4.3 mm
Rain · ahead0.7 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
19°C est.ideal 10–16°C
0°14°28°
How to fish it · for Brown Trout
When
Through the open trout season. Spring olives once snowmelt drops; sedges through summer; small dark flies into autumn close.
Where
Pool tails and pocket water through the Ossau valley. Pyrenean piedmont character — clear water, intimate scale.
Method
Upstream dry to risers; nymph the deeper pockets between hatches. Short casts, quiet wading.
Kit
9 ft #4 — French freestone default. Floating line, 12 ft leader to 4 to 5 lb fluoro. Studded boots.
Why this works
Water at 18.7°C — above the brown trout caution line (18°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots.
Likely species
Caddisflies
Gammarids
Hatch timeline · todayPeak at 6pm

12pm(now) — Flying Ants

Stage: Terrestrials on topApproach: Dry flyActivity: 32%
Also:Reed Smut23%
Peak emergence windowWeather boost4 food groups active

Peak activity at 6pm — Evening Sedge (Evening Sedge, Weather boost)

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 3 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
Evening SedgeHatch
2
3
3
3
2
Alpine RhithrogenaHatch
1
2
2
1
Large Dark OliveHatch
1
2
2
1
Iron BlueHatch
1
2
2
2
2
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.

What's coming
Plan ahead
5-day outlook
Water here around 19°C. Nothing cooler within range — carry a thermometer.
Gallery · 2
  1. A wide clear river with turquoise water flowing over gravel past a forested limestone ridge in the Pyrenees
    The Gave d'Ossau at Castet
  2. Terrain map of the venue
    Terrain map
About this water

The Gave d'Ossau is upper Béarn — snowmelt-fed Pyrenean freestone dropping out of the Pic du Midi country and running north through the valley towards Oloron, where it feeds the bigger Gave system. It carries wild brown trout throughout its middle and upper reaches and holds them in the kind of fast, cold water that rewards anyone willing to get into it properly. The reaches around Laruns and Sévignacq-Meyracq are fly-only no-kill, barbless on a single hook, and the AAPPMA has been managing the fishing with more care than most. Tight-line nymphing with beadheads is the staple for the pocket water; by late June the caddis and olives start triggering genuine dry-fly windows in the evenings. Snowmelt keeps it cold into July, which means the prime window stretches further here than on the lower Gave — a Pyrenean river that looks like the postcard and fishes like one.

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

WFD classification · FRFR256A

The full read · show the working · for Brown Trout · confidence 80%
How the 0 is built — score × weight = contribution
Temperature29 × 28%8.1
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time40 × 13%5.2
Pressure80 × 7%5.6
Insect activity61 × 12%7.3
Conditions total= 61
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
Related guides
Pyrenees PlaybookFrench riversEuro Nymphingsubsurface methods
Booking & contacts