Freestone · Mixed · Haute-Savoie / Savoie, FR

Arly

A wide alpine river flows over a gravel bed between forested banks, with mountains rising in the background near Césarches, Savoie, France.

The Arly comes down off the Aravis fast and cold, gathering snowmelt through spring before slowing enough in its middle reaches to become properly fishable.

Prime · Brown Trout
Small Perdigón · 16-20
New ruleReported 1 Aug 2026

Severe drought restrictions (alerte renforcée) in force

The Fier zone (Dept 74) is at alerte renforcée — the second-highest French drought tier — under a préfectoral arrêté. Fishing itself is not named as prohibited, but water is severely restricted and flows are likely very low; fish with care and check locally.

Arrêté préfectoral n°37507

Temporary notices from official orders and recent fishery reports — they clear automatically once out of date. Always confirm locally before travelling.

Primelive now
About as good as it gets
River steady at a fishable height. On the feed top to bottom — start on the rises with a dry, drop a nymph if they stay down.
90% confidence
What moved it
  • LevelProxyvia Isère (Combe de Savoie)
  • Water temp16.4°C
  • ClarityClear
Today's fly
Small Perdigón
Small Perdigón16-20
Euro-nymph
Conditions on the water
Proxy gauge
Level
Steady
Proxy
via Isère (Combe de Savoie)
Water temp16.4°C
ClarityClear
Weather17°C
WindNE 4 km/h
Pressure1017 hPa
Rain · recent0.7 mm
Rain · ahead5.5 mm

No gauge on this water — conditions are inferred from Isère (Combe de Savoie). The trend transfers, the absolute level does not.

Water temperature for Brown Trout
Warm — slow
16°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
Excellent — conditions well-balanced, with water clarity particularly in your favour.
Hatch timeline · todayPeak at 6pm

Hatch predictions

Today's headline hatch shown — see all 12 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 4 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
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

French nymph-first water. Fast current, technical presentation, weighted nymphs and emergers, with dry flies when fish rise.

What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gallery · 2
  1. A wide alpine river flows over a gravel bed between forested banks, with mountains rising in the background near Césarches, Savoie, France.
    The River Arly near Césarches, Savoie
  2. Terrain map of the venue
    Terrain map
About this water

The Arly comes down off the Aravis fast and cold, gathering snowmelt through spring before slowing enough in its middle reaches to become properly fishable. You want it in late June through July — that short window after the runoff has cleared and before the summer drawdown bites. The fish are wild browns, small but vigorous, in pocket water and short plunge pools that reward a short line and a heavy nymph. Don't come expecting length; this is an intimate river in a big landscape, and the pleasure is in reading the water rather than covering it. The upper valley around Ugine is the postcard country; the lower reaches towards Albertville warm by August and the fishing moves upstream. Bring a 9ft 4-weight for the middle river and a shorter rod for the headwaters.

  • Mixed
Water quality (WFD)
  • EcologyGood
  • ChemicalUnknown

WFD classification · FRDR362A

The full read · show the working · for Brown Trout · confidence 90%
How the 83 is built — score × weight = contribution
Temperature90 × 28%25.2
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time70 × 13%9.1
Pressure80 × 7%5.6
Insect activity68 × 12%8.2
Conditions total= 83
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via Isère (Combe de Savoie)proxy
Prey activitysurvey-backed invertebrate datasurvey
Directions
Seasons & zones
  • Trout 2nd Saturday of March3rd Sunday of September
Related guides
Booking & contacts
Clubs & associations