Freestone · Limestone · Haute-Savoie

Usses

A clear forest stream, the Usses river, flowing over rocks between snow-covered trees near Cruseilles, Haute-Savoie, France.
Contributor photo

Les Usses @ Champ Beau Fond @ Cruseilles

Guilhem Vellut - CC BY 2.0

The Usses runs in limestone gorges through the Albanais country south of Annecy — one of those rivers that belongs to its landscape so completely you can't imagine it anywhere else.

Poor · Brown Trout
Small Perdigón · 16-20
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
  • LevelDry recentlyNo gauge reading
  • Water temp22.7°C
  • ClarityClear
Today’s fly
Small Perdigón
Small Perdigón16-20
Euro-nymph
Conditions on the water
Estimate
Level
Dry recently
No gauge reading
Water temp22.7°C
ClarityClear
Weather31°C
WindSW 9 km/h
Pressure1016 hPa
Rain · recent0.0 mm
Rain · ahead22.7 mm

No gauge on this water — readings are regional estimates from weather, not a live gauge.

Water temperature for brown trout
Warm — slow
23°C est.ideal 1016°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 22.7°C. This is the line where catch-and-release kills brown trout. Do not fish for them today.
Hatch timeline · todayQuiet day

Hatch predictions

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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 · July highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
1
Alpine RhithrogenaHatch
2
3
3
2
Sculpin / Baitfish (Rivers)Hatch
2
3
3
3
3
3
3
3
2
March BrownHatch
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
What's coming
Plan ahead
5-day outlook
Cooler water nearby · 1
Probably above the brown trout safety line — these are likely cooler, but carry a thermometer.
Gallery · 2
  1. A clear forest stream, the Usses river, flowing over rocks between snow-covered trees near Cruseilles, Haute-Savoie, France.
    Les Usses @ Champ Beau Fond @ Cruseilles
  2. Terrain map of the venue
    Terrain map
About this water

The Usses runs in limestone gorges through the Albanais country south of Annecy — one of those rivers that belongs to its landscape so completely you can't imagine it anywhere else. It fishes as varied as it looks: short pools, pocket water, gravel runs, the occasional slow glide under overhanging oak. Wild brown trout throughout, reasonable hatches of olives and caddis, and pocket water that rewards a nymph bounced through the seams. The gorges make some sections a commitment — you'll be scrambling in and scrambling out — but that's what keeps them quiet. Spring and early summer are the prime window. By August you'll be fishing the faster pockets where the oxygen holds up and the fish are willing to work for the food.

  • Limestone
Water quality (WFD)
  • EcologyModerate
  • ChemicalUnknown

WFD classification · FRDR541A

The full read · show the working · for brown trout · confidence 90%
How the 6 is built — score × weight = contribution
Temperature3 × 28%0.8
Flow60 × 22%13.2
Clarity95 × 18%17.1
Feeding Time60 × 13%7.8
Pressure80 × 7%5.6
Insect activity51 × 12%6.1
Limiting factor: Water temperature (22.7°C) is outside Brown Trout's preferred range (10–16°C)= 51
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
Seasons & zones
  • Trout2nd Saturday of March → 3rd Sunday of September
Related guides
Booking & contacts