Chalk Stream · Limestone · Bela Krajina / Semič

Krupa

Krupa — Krupa river in winter

One of the shortest rivers in Slovenia — a karst spring near Semič in Bela Krajina, flowing barely a couple of kilometres before it's spent.

Marginal · Brown Trout
Elk Hair Caddis · 12-16
Marginallive now
Slow going — pick your moments
River temperature is the limiting factor today, not the flow. Fish dawn or dusk if you go at all, and handle everything with extra care.
80% confidence
What moved it
  • LevelDry recentlyNo gauge reading
  • Water temp19.3°C
  • ClarityClear
Today's fly
Elk Hair Caddis
Elk Hair Caddis12-16
High-confidence seasonal pick
Conditions on the water
Estimate
Level
Dry recently
No gauge reading
Water temp19.3°C
ClarityClear
Weather26°C
WindW 5 km/h
Pressure1015 hPa
Rain · recent0.0 mm
Rain · ahead0.0 mm

No gauge on this water — readings are regional estimates from weather, not a live gauge.

Water temperature for Brown Trout
Warm — slow
19°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
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.
Hatch timeline · todayPeak at 6pm

Hatch predictions

Today's headline hatch shown — see all 10 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 3 with Pro.

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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
Brown SedgeHatch
2
3
2
Freshwater ShrimpHatch
2
3
3
3
3
3
3
3
3
3
3
2
Blue Winged OliveHatch
2
3
3
3
3
2
Mayfly (Green Drake)Hatch
2
2

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

Ranked for today
Brown Trout fly box

Ultra-clear spring-fed rivers with large educated trout. Sight fishing, technical presentation, fine tippets. Euro-nymphing dominant subsurface method. Exceptional dry-fly windows during hatch periods. Gacka is the flagship water.

Permits & access
Permit required — see local rules.
  • Bela Krajina ribiška družina (likely RD Črnomelj) — not independently confirmed.
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.
Mrežnica
40 km
~18°C
Brown trout · Grayling
Gallery · 2
  1. Krupa — Krupa river in winter
    Krupa river in winter
  2. Terrain map of the venue
    Terrain map
About this water

One of the shortest rivers in Slovenia — a karst spring near Semič in Bela Krajina, flowing barely a couple of kilometres before it's spent. Marked medium confidence deliberately: it holds trout, but the detail on stocking, permit terms and exact species mix wasn't pinned down with the same certainty as the rest of this pack, so treat it as a lead worth checking locally rather than a settled record.

  • River
  • Limestone
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 Time55 × 13%7.2
Pressure80 × 7%5.6
Insect activity67 × 12%8.0
Conditions total= 65
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
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
  • Trout 1 March → 30 September
Related guides
Chalkstream Playbookchalk stream tacticsAlpine Streamsmountain entomologyMarble TroutSoča system
Booking & contacts