Chalk Stream · Limestone · Bela Krajina / Semič, SI

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.

Today · About as good as it gets
Pink Shrimp
Forecast · Today
About as good as it gets
On the feed top to bottom — start on the rises with a dry, drop a nymph if they stay down.
75% projected
Today's fly
Pink Shrimp
Pink Shrimp
Conditions on the water · Today
Estimate
Level
Dry recently
No gauge reading
Water temp10.9°C
ClaritySlightly coloured
Weather18°C
WindN 8 km/h
Pressure1022 hPa
Rain · recent0.9 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
Ideal
11°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 — water temperature is right today, though insect activity could be better.
Likely species
Mayflies
Caddisflies
Damselflies & dragonflies
Hatch timeline · todayPeak at 6pm

12pm(now) — Black Midge

Stage: On emergersApproach: Emerger or dryActivity: 57%
Also:Autumn Needle Fly38%Iron Blue35%Brown Sedge29%
Peak emergence window8 food groups active

Peak activity at 6pm — Large Cinnamon Sedge (Large Cinnamon Sedge, Weather boost)

Sub-surface · on the nymphunder the surface

Hatch predictions

Top nymph shown — see all 2 guilds as a supporter.

Start free trial

14-day free trial. Cancel anytime.

Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Top prey shown — see all 4 as a supporter.

Start free trial

14-day free trial. Cancel anytime.

Evidence
Records-basedModerate confidence

Based on species-occurrence records, not local invertebrate surveys.

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
Brown SedgeHatch
2
3
3
3
2
Small SpurwingHatch
2
3
3
3
2
Freshwater ShrimpHatch
2
3
3
3
3
3
3
3
3
3
3
2
Small Dark OliveHatch
2
3
3
3
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.

SW
Streamer / Woolly BuggerTop
6-10 · Pattern
High-confidence seasonal pick
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
Other water nearby · 5
River Kolpa
26 km
Brown trout · Grayling · Hucho
Vitunjčica
34 km
Brown trout
Krka
35 km
Brown trout · Grayling
Mrežnica
38 km
Brown trout · Grayling
Curak
40 km
Brown trout
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 90%
How the 80 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow60 × 22%13.2
Clarity95 × 18%17.1
Feeding Time70 × 13%9.1
Pressure80 × 7%5.6
Insect activity59 × 12%7.1
Conditions total= 80
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout 1 March → 30 September
Related guides
Chalkstream Playbooklimestone spring creek — same tacticsAlpine Streamsmountain entomologyMarble TroutSoča system
Booking & contacts