Freestone · Limestone Influenced · Shikoku

Niyodo River

Niyodo River venue image
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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.

Species

Slow going — pick your moments

Low and clear — careful approach country. Cover and shadow are doing the work today.

The water's warmed to around 18°C, running clear, sitting at a steady height.

80% confidence in this read
Water temperature for amago
Warm — slow
18°C est.ideal 9–17°C
0°14°28°
The full read · show the working · for amago · confidence 80%
How the 27 is built — score × weight = contribution
Temperature73 × 28%20.4
Flow45 × 22%9.9
Clarity95 × 18%17.1
Feeding Time30 × 13%3.9
Pressure80 × 7%5.6
Insect activity53 × 12%6.4
Conditions total= 63
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
What would change the calculation
The dawn and dusk windows score higher than the midday lull.
Conditions
○Regional est.
Level
Dry recently
No gauge reading
Water temp
18.0°C
Estimated
Clarity
Clear
Air temp
23°C
Wind
E 8 km/h
Light breeze
Pressure
1012 hPa
Rain · 48h
0.0 mm
No meaningful rain
Rain · ahead
8.3 mm
Light rain · next 48h

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

Hatch timeline · todayQuiet day

Hatch predictions

Today's headline hatch shown — see all 7 active hatches hour by hour with Pro.

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Evidence
ModelledModerate confidence

Modelled from regional ecology — no survey or occurrence data for this water yet.

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°C — above the masu salmon caution line (17°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots. Otherwise poor — water clarity is in the right range.
Through the year
0–3 scale · June highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Stenopsyche CaddisHatch
2
3
3
2
Cicada (Semi)Hatch
2
2
GrannomHatch
2
2
Evening SedgeHatch
2
3
3
3
2

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

Gallery · 1
  1. Terrain map of the venue
    Terrain map
Permits & access
Permit required — see local rules.
  • Co-operative yugyoken required; spawning closure in autumn
  • Confirm reach and method rules.
Directions
Apple MapsGoogle Maps
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
Seasons & zones
  • Charlate February to April → late September to mid-October
Water here around 18°C. Nothing cooler within range — carry a thermometer.
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