Karst · Limestone · Ain / Revermont (Pont-d'Ain)

Suran

Auberge du Suran venue image
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The Suran is a Revermont river — the long limestone scarp that runs down the western edge of the Jura and ends somewhere near the Ain.

Marginal · Brown Trout
CDC Emerger · 16-20
Marginallive now
Slow going — pick your moments
River steady at a fishable height. Take your time — read the water before you cast.
80% confidence
What moved it
  • LevelProxyvia Ain
  • Water temp19.3°C
  • ClarityClear
Today’s fly
CDC Emerger
CDC Emerger16-20
Dead-drift
Conditions on the water
Proxy gauge
Level
Steady
Proxy
via Ain
Water temp19.3°C
ClarityClear
Weather21°C
WindE 9 km/h
Pressure1018 hPa
Rain · recent0.2 mm
Rain · ahead2.2 mm

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

Water temperature for brown trout
Warm — slow
19°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 19.3°C — above the brown trout caution line (18°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots. Otherwise poor — water clarity is in the right range.
Hatch timeline · todayQuiet day

Hatch predictions

Today's headline hatch shown — see all 7 active hatches hour by hour 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 · 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
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.
  • AAPPMA de l'Ain and local associations share management
  • Some fly-only and no-kill parcours — check locally.
What's coming
Plan ahead
5-day outlook
Cooler water nearby · 1
Water here around 19°C — probably warm enough to stress brown trout. These are likely cooler.
Gallery · 1
  1. Terrain map of the venue
    Terrain map
About this water

The Suran is a Revermont river — the long limestone scarp that runs down the western edge of the Jura and ends somewhere near the Ain. It's neither quite chalk stream nor quite freestone, which gives it a character most anglers don't bother trying to pin down. The water is clear, the banks are friendly, the valley is gentle enough to walk without swearing, and the trout are decent wild fish that will come to a well-presented olive without feeling they've been tricked. Hatches are predictable through the spring — olives, then mayfly in late May, then sedges from June. Summer low water is the main challenge: the Suran can drop to a trickle in a hot August and needs thunderstorm-driven recharge to recover. But pick your window in May or early June and it's one of the most undervalued trout streams in eastern France.

  • Limestone
Water quality (WFD)
  • EcologyModerate
  • ChemicalUnknown

WFD classification · FRDR2015

The full read · show the working · for brown trout · confidence 80%
How the 32 is built — score × weight = contribution
Temperature35 × 28%9.8
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time40 × 13%5.2
Pressure80 × 7%5.6
Insect activity64 × 12%7.7
Conditions total= 63
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via Ainproxy
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
  • Grayling3rd Saturday of May → 3rd Sunday of September
Related guides
Booking & contacts