Freestone · Limestone Influenced · Shikoku, JP

Niyodo River

Niyodo River in Ino town, Kochi pref Japan
Tomorrow · Slow going — pick your moments
Sakasa kebari
Forecast · Tomorrow
Slow going — pick your moments
Slow going — pick your moments and do not force it.
80% projected
Today's fly
Sakasa kebari
Sakasa kebari
Conditions on the water · Tomorrow
Estimate
Level
Light rain recently
No gauge reading
Water temp17.8°C
ClaritySlightly coloured
Weather25°C
WindN 7 km/h
Pressure1021 hPa
Rain · recent8.2 mm
Rain · ahead4.4 mm

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

Water temperature for Amago
Warm — slow
18°C est.ideal 9–17°C
0°14°28°
How to fish it · for Amago
When
March/April to the autumn closure
Where
The Niyodo is famous for a colour — 'Niyodo blue', the luminous clarity that limestone gives its water — and runs through the green mountains of Kōchi as one…
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 12 Uhr

12 Uhr(now) — Glossosoma (Japan)

Stage: Taking dunsApproach: Dry flyActivity: 95%
Also:Heather Fly94%Reed Smut70%Isonychia japonica53%
Peak emergence windowWeather boost10 food groups active

Peak activity at 12 Uhr — Glossosoma (Japan) (Glossosoma (Japan), 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 2 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 · Amago
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
  • Confirm reach and method rules.
What's coming
Plan ahead
5-day outlook
Water here around 19°C. Nothing cooler within range — carry a thermometer.
Gallery · 2
  1. Niyodo River in Ino town, Kochi pref Japan
    Clear water river in Shikoku.
  2. Terrain map of the venue
    Terrain map
Conservation note

White-spotted char (iwana) and amago — the prized Shikoku red-spotted native.

The full read · show the working · for Amago · confidence 80%
How the 23 is built — score × weight = contribution
Temperature49 × 28%13.7
Flow60 × 22%13.2
Clarity95 × 18%17.1
Feeding Time50 × 13%6.5
Pressure80 × 7%5.6
Insect activity47 × 12%5.6
Conditions total= 62
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 9–17 °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