Freestone · Mixed · Alps / Savoie

Isère (Combe de Savoie)

A wide alpine river flowing past tree-lined banks, with misty mountains in the background near Montmelian, Savoie.
Contributor photo

Isere @ Pont Morens @ Montmelian

Guilhem Vellut - CC BY 2.0

The Isère in Combe de Savoie is big alpine water — 1st-category from Pont Royal to Pontcharra.

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 temp22.5°C
  • ClarityClear
Today’s fly
Small Perdigón
Small Perdigón16-20
Euro-nymph
Conditions on the water
Estimate
Level
Dry recently
No gauge reading
Water temp22.5°C
ClarityClear
Weather22°C
WindE 4 km/h
Pressure1017 hPa
Rain · recent0.3 mm
Rain · ahead16.3 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 10–16°C
0°14°28°
How to fish it · for brown trout
When
Through the open trout season. Late spring once snowmelt drops; sedges through summer; small dark flies into autumn close.
Where
Pool tails and the seams behind boulders through the Combe de Savoie. The Isère is bigger water than most Alpine tributaries — wadeable but demanding.
Method
Upstream dry to risers; dry-dropper through the riffles. The water reads clear — long leader, fine tippet. Move slowly, cast accurately.
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 22.5°C. This is the line where catch-and-release kills brown trout. Do not fish for them today.
Hatch timeline · todayQuiet day

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Sub-surface · on the nymphunder the surface

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Beyond the hatch · worth watchingambient prey

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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
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
Permits & access
Permit required — see local rules.
  • AAPPMA permits.
What's coming
Plan ahead
5-day outlook
Water here around 23°C. Nothing cooler within range — carry a thermometer.
Gallery · 2
  1. A wide alpine river flowing past tree-lined banks, with misty mountains in the background near Montmelian, Savoie.
    Isere @ Pont Morens @ Montmelian
  2. Terrain map of the venue
    Terrain map
About this water

The Isère in Combe de Savoie is big alpine water — 1st-category from Pont Royal to Pontcharra. Snowmelt character with improving conditions as summer progresses and water clears. Technical at high water, more accessible as levels drop. Fly-fishing opportunity. Check Savoie regulations for access and restrictions.

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

WFD classification · FRDR527A

The full read · show the working · for brown trout · confidence 90%
How the 8 is built — score × weight = contribution
Temperature4 × 28%1.1
Flow60 × 22%13.2
Clarity95 × 18%17.1
Feeding Time40 × 13%5.2
Pressure80 × 7%5.6
Insect activity43 × 12%5.2
Limiting factor: Water temperature (22.5°C) is outside Brown Trout's preferred range (10–16°C)= 47
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
  • Trout2nd Saturday of March → 3rd Sunday of September
  • Grayling3rd 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