Freestone · Limestone Influenced · Shikoku, JP

Niyodo River

Niyodo River in Ino town, Kochi pref Japan

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 of the most beautiful rivers in Japan, holding amago and iwana in pools you can see straight to the bottom of.

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 12pm

12pm(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 12pm — Glossosoma (Japan) (Glossosoma (Japan), Peak emergence window)

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
Amago fly box
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
About this water

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 of the most beautiful rivers in Japan, holding amago and iwana in pools you can see straight to the bottom of. Sight-fishing water in a landscape of gorges and clear pools.

Under the surface

A river celebrated for its luminous limestone-blue clarity, running through the green Kōchi mountains of Shikoku. Amago and iwana hold in pools so clear they seem bottomless; this is sight-fishing water, gorge and pool and astonishing colour.

Wading: Gin clear water, slick bedrock — stealth essential

  • River
  • Limestone influenced
  • Confined
  • Pool riffle
  • Pocket water
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