Mountain Freestone · Granite · Honshū, JP

Kurobe River (Kurobe Gorge)

Jujikyo in Kurobe Gorge

The Kurobe cuts one of the deepest gorges in Japan through the granite of the Northern Alps, a river of dam, tunnel and sheer rock where iwana live in cold pockets at the foot of immense walls.

Tomorrow · Not the day for it
Sakasa kebari
Forecast · Tomorrow
Not the day for it
Not much stacked in your favour today. Worth an hour if you are nearby, not worth the special trip.
80% projected
Today's fly
Sakasa kebari
Sakasa kebari
Conditions on the water · Tomorrow
Estimate
Level
Moderate rain recently
No gauge reading
Water temp17.3°C
ClarityVery coloured
Weather21°C
WindN 19 km/h
Pressure1018 hPa
Rain · recent21.3 mm
Rain · ahead0.4 mm

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

Water temperature for White-spotted Char
Warm — slow
17°C est.ideal 7–14°C
0°14°28°
How to fish it · for White-spotted Char
When
Summer, when the high country is open and snow has cleared
Where
The Kurobe cuts one of the deepest gorges in Japan through the granite of the Northern Alps, a river of dam, tunnel and sheer rock where iwana live in cold…
Why this works
Water at 17.9°C — above the white-spotted char caution line (16°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots.
Likely species
Caddisflies
Damselflies & dragonflies
Hatch timeline · tomorrowPeak at 2pm

12pm(now) — Heather Fly

Stage: Terrestrials on topApproach: Dry flyActivity: 60%
Also:Glossosoma (Japan)56%Daddy Long Legs47%Isonychia japonica39%
Peak emergence windowWeather boost11 food groups active

Peak activity at 2pm — Isonychia japonica (Isonychia japonica, Weather boost)

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
Ephemera japonica (Upstream Keiryu Mayfly)Hatch
2
3
2
Stenopsyche CaddisHatch
2
3
3
2
Cicada (Semi)Hatch
2
2
Epeorus latifolium (Riffle Mayfly)Hatch
2
3
3
3
3
3
2

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

Ranked for today
White-spotted Char fly box
CM
Clinger mayfly dun (Epeorus / Rhithrogena)
14–18 · Dry
Cast to rising fish and let it drift drag-free.
Permits & access
Permit required — see local rules.
  • Area rules and serious access constraints; confirm permits and route
  • Mountain safety is essential.
What's coming
Plan ahead
5-day outlook
Water here around 18°C. Nothing cooler within range — carry a thermometer.
Gallery · 2
  1. Jujikyo in Kurobe Gorge
    V-shaped gorge in Toyama.
  2. Terrain map of the venue
    Terrain map
About this water

The Kurobe cuts one of the deepest gorges in Japan through the granite of the Northern Alps, a river of dam, tunnel and sheer rock where iwana live in cold pockets at the foot of immense walls. Hard, dramatic, half-wilderness water reached by mountain railway and trail, fished by those who go deep into the range.

Under the surface

A river in one of Japan's deepest granite gorges, in the heart of the Northern Alps, between sheer walls and the famous Kurobe dam. Iwana hold in cold pockets beneath the cliffs; access is by mountain railway, tunnel and trail. Spare, dramatic, half-wilderness keiryu.

Wading: Deep gorge, sheer walls, cold swift water, serious access

  • River
  • Granite
  • Confined
  • Pocket water
  • Step pool
Conservation note

White-spotted char (iwana).

The full read · show the working · for White-spotted Char · confidence 80%
How the 18 is built — score × weight = contribution
Temperature9 × 28%2.5
Flow40 × 22%8.8
Clarity15 × 18%2.7
Feeding Time55 × 13%7.2
Pressure75 × 7%5.3
Insect activity33 × 12%4.0
Limiting factor: Water temperature (17.9°C) is outside White-spotted Char's preferred range (7–14°C)= 31
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
What would change the calculation
Cooler water — back toward the 7–14 °C ideal band — would lift the score and ease welfare.
A drop and clear would lift the flow and clarity scores.
The dawn and dusk windows score higher than the midday lull.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Char late February to April → late September to mid-October

    Honshu/Shikoku/Kyushu keiryu are managed by local fishery co-operatives — a yugyoken (day/annual ticket) is required, and most streams close around 30 September / mid-October for spawning. Species are surfaced in prose only (no engine slugs for yamame, amago or iwana). Legal status: guidance_not_permission.

Related guides
Euro Nymphingsubsurface methods
Booking & contacts