Freestone · Volcanic · Kyūshū, JP

Gokase River (Takachiho)

Manai Falls at Takachiho Gorge
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
Dry recently
No gauge reading
Water temp18.5°C
ClarityClear
Weather25°C
WindN 6 km/h
Pressure1021 hPa
Rain · recent0.2 mm
Rain · ahead2.5 mm

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

Water temperature for Yamame
Warm — slow
19°C est.ideal 9–16°C
0°14°28°
How to fish it · for Yamame
When
Spring to the autumn closure; cooler upper reaches in high summer
Where
The Gokase rises in the volcanic highlands of Miyazaki and runs through the mythic gorge of Takachiho — basalt-columned, waterfall-hung, woven into the oldest…
Why this works
Water at 18.5°C — above the masu salmon caution line (17°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots.
Hatch timeline · tomorrowPeak at 12h

12h(now) — Heather Fly

Stage: Terrestrials on topApproach: Dry flyActivity: 95%
Also:Glossosoma (Japan)93%Black Gnat68%Isonychia japonica53%
Peak emergence windowWeather boost10 food groups active

Peak activity at 12h — Heather Fly (Heather Fly, Peak emergence window)

Sub-surface · on the nymphunder the surface

Hatch predictions

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Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Top prey shown — see all 3 as a supporter.

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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
Stenopsyche CaddisHatch
2
3
3
2
Cicada (Semi)Hatch
2
2
Ephemera strigata (Mid-Reach Keiryu Mayfly)Hatch
2
3
3
3
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
Fly box · Yamame
EH
Elk Hair / Stenopsyche caddis
12–14 · Sedge
Evening sedge — twitch or dead-drift it as the light goes.
CB
Cicada & beetle terrestrials (midsummer)
10–12 · Terrestrial
Fish it tight to the bank on warm, breezy days.
Permits & access
Permit required — see local rules.
  • Co-operative yugyoken required; spawning closure in autumn
  • Southern waters warm early — fish higher and cooler in summer.
What's coming
Plan ahead
5-day outlook
Water here around 19°C. Nothing cooler within range — carry a thermometer.
Gallery · 2
  1. Manai Falls at Takachiho Gorge
    Volcanic basalt gorge in Kyūshū.
  2. Terrain map of the venue
    Terrain map
Conservation note

White-spotted char (iwana) and yamame in the cooler upper water.

The full read · show the working · for Yamame · confidence 80%
How the 23 is built — score × weight = contribution
Temperature27 × 28%7.6
Flow45 × 22%9.9
Clarity95 × 18%17.1
Feeding Time40 × 13%5.2
Pressure80 × 7%5.6
Insect activity50 × 12%6.0
Conditions total= 51
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 9–16 °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
  • 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