Karst · Limestone · Burgundy / Côte-d'Or

Armançon (Upper Trout Reach)

Armançon (Upper Trout Reach) terrain map
Terrain map

The upper Armançon, before it becomes the broad canal-flanked river that runs across the Burgundy plain, is a Côte-d'Or trout stream of real quality.

Marginal · Brown Trout
CDC Emerger · 16-18
Marginallive now
Slow going — pick your moments
Low and clear — careful approach country. Cover and shadow are doing the work today.
80% confidence
What moved it
  • LevelProxyvia Loue
  • Water temp19.5°C
  • ClarityClear
Today’s fly
CDC Emerger
CDC Emerger16-18
Dead-drift
Conditions on the water
Proxy gauge
Level
Steady
Proxy
via Loue
Water temp19.5°C
ClarityClear
Weather27°C
WindN 14 km/h
Pressure1022 hPa
Rain · recent6.0 mm
Rain · ahead1.0 mm

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

Water temperature for brown trout
Warm — slow
20°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 19.5°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 8 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
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 Montbard / Semur-en-Auxois
  • Standard 1ère catégorie.
What's coming
Plan ahead
5-day outlook
Water here around 20°C. Nothing cooler within range — carry a thermometer.
About this water

The upper Armançon, before it becomes the broad canal-flanked river that runs across the Burgundy plain, is a Côte-d'Or trout stream of real quality. It rises on the Jurassic limestone near Essarois, runs through Montbard and Semur-en-Auxois, and gathers water from a long series of spring feeders as it goes. The character is limestone throughout: clear water, weedy pool tails, slow seams, and wild brown trout that know exactly what a size 16 olive looks like and what it does not. Fish the upper and middle reaches for brown trout and the occasional grayling. The hatches are strong — Baetis through spring, grannom in April, BWO throughout, and reliable caddis from May — and the limestone buffering keeps the river in condition even through dry spells. The trout are selective in the slow glides and bolder in the faster runs below the bridges. Start small — size 16 or 18 on fine tippet — and expect the fish to inspect rather than grab. The upper Armançon rewards the kind of patient, careful fishing that people associate with English chalk streams, without any of the associated expense or fuss.

  • Limestone
Water quality (WFD)
  • EcologyModerate
  • ChemicalGood
What this classification means

WFD chemical status Failing to achieve good → Good corrected to EEA WISE 2022 (3rd RBMP) classification for waterbody FRHR61C (was a stale earlier-cycle value). Source: EEA WISE SWB_SurfaceWaterBody (discodata.eea.europa.eu), verified 2026-06-18.

WFD classification · FRHR61C

The full read · show the working · for brown trout · confidence 80%
How the 31 is built — score × weight = contribution
Temperature32 × 28%9.0
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time65 × 13%8.5
Pressure80 × 7%5.6
Insect activity58 × 12%7.0
Conditions total= 65
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via Loueproxy
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 → 31 December
Related guides
Booking & contacts