Freestone · Limestone · Wallonia / Namur Province, BE

Lesse

Photo of Lesse

Ardennes river famous for the caves at Han-sur-Lesse where the river disappears underground.

Tomorrow · Closed season
Coch-y-bonddu
Forecast · Tomorrow
Closed season
Out of season. Try elsewhere.
45% projected
Today's fly
Coch-y-bonddu
Coch-y-bonddu
Conditions on the water · Tomorrow
Live gauge
Level
Rising
0.02 m
Lifting fast
Water temp15.8°C
ClarityVery coloured
Weather22°C
WindN 19 km/h
Pressure1017 hPa
Rain · recent0.0 mm
Rain · ahead3.9 mm

The nearest gauge doesn't record temperatures, so we've estimated it — defer to the river keeper's advice.

Water temperature for Brown Trout
Ideal
16°C est.ideal 10–16°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.
Likely species
Mayflies
Caddisflies
Gammarids
Hatch timeline · tomorrowPeak at 11am

12pm(now) — Reed Smut

Stage: On emergersApproach: Emerger or dryActivity: 45%
Also:Heather Fly39%Cinnamon Sedge26%Pale Watery23%
Peak emergence window11 food groups active

Peak activity at 11am — Reed Smut (Reed Smut, Peak emergence window)

Sub-surface · on the nymphunder the surface

Hatch predictions

Top nymph shown — see all 3 guilds as a supporter.

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Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Top prey shown — see all 4 as a supporter.

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Evidence
Survey-backed · regionalHigh confidence

Backed by regional invertebrate surveys; no sampling on this exact reach yet.

Through the year
0–3 scale · September highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
1
Grayling seasonSeason
2
1
1
2
2
2
2
2
2
Evening SedgeHatch
2
3
3
3
2
Large Dark OliveHatch
1
2
2
1
Iron BlueHatch
1
2
2
2
2
2
2
1
Blue Winged OliveHatch
1
2
2
2
2
1

Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.

Ranked for today
Brown Trout fly box

A proper Ardennes river-trout pack for Wallonia, centred on clear to lightly coloured rivers with trout and some classic fly-fishing culture.

SS
Small Streamer
6-10 · Pattern
Swing
Permits & access
Permit required — see local rules.
  • Permis de pêche (Wallonia) / Visverlof (Flanders)
  • Foreign anglers can purchase a Walloon fishing permit (permis de pêche) online or at post offices without residency requirements
  • For Flemish waters, the visverlof is similarly available
  • No prior fishing exam required in either region.
What's coming
Plan ahead
5-day outlook
Other water nearby · 3
Semois
27 km
Brown trout · Grayling
Ourthe
37 km
Brown trout · Grayling
Pisciculture de Vendresse
58 km
Rainbow trout
Gallery · 2
  1. Photo of Lesse
    Lesse
  2. Terrain map of the venue
    Terrain map
About this water

Ardennes river famous for the caves at Han-sur-Lesse where the river disappears underground. Brown trout and grayling in limestone-rich water with good hatches. Some sections experience kayak traffic in summer—fish early or late. Club permits required.

  • Limestone
Water quality (WFD)
  • Ecology: Moderate
  • Chemical: Unknown

WFD classification · BERW06_LE07R

The full read · show the working · for Brown Trout · confidence 90%
How the 83 is built — score × weight = contribution
Temperature89 × 28%24.9
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time65 × 13%8.5
Pressure80 × 7%5.6
Insect activity76 × 12%9.1
Conditions total= 83
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitysurvey-backed invertebrate datasurvey
What would change the calculation
The dawn and dusk windows score higher than the midday lull.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout 3rd Saturday of March → 30 September
  • Grayling 1 June → 28 February
Related guides
Grayling Playbookgrayling tacticsEuro Nymphingsubsurface methods
Booking & contacts