Spate · Granite · Corsica / Corse-du-Sud (Ajaccio hinterland)

Gravona

Gravona terrain map
Poor · Brown Trout
CDC Emerger · 16-18
Poorlive now
Not the day for it
River temperature is the limiting factor today, not the flow. This is not the day to push it. Check the thermal advice above before you head out.
80% confidence
What moved it
  • Level0.50 mLast reading 12h ago
  • Water temp21.3°C
  • ClarityClear
Today's fly
CDC Emerger
CDC Emerger16-18
Dead-drift
Conditions on the water
Live gauge
Level
Steady
0.50 m
Last reading 12h ago
Water temp21.3°C
ClarityClear
Weather22°C
WindE 4 km/h
Pressure1019 hPa
Rain · recent0.1 mm
Rain · ahead1.8 mm

The nearest gauge doesn't record temperatures, so we've estimated it — defer to the river keeper's advice.

Water temperature for Brown Trout
Warm — slow
21°C est.ideal 1016°C
0°14°28°
How to fish it · for Brown Trout
When
Nymphing can work through most of the day.
Where
Cover mixed depths.
Method
Start with tight-line nymphs and adjust if fish rise or drift higher.
Kit
9 ft #4 rod, floating line, 12 ft tapered leader to 4–5 lb fluoro tippet.
Why this works
Water at 21.3°C — above the brown trout caution line (18°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots.
Hatch timeline · todayPeak at 6pm

Hatch predictions

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

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Sub-surface · on the nymphunder the surface

Hatch predictions

See the full sub-surface read with Pro.

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Beyond the hatch · worth watchingambient prey

Hatch predictions

Top prey shown — see all 2 with Pro.

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Evidence
Survey-backed · regionalModerate confidence

Backed by regional invertebrate surveys; no sampling on this exact reach yet.

Through the year
0–3 scale · August highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
1
March BrownHatch
2
3
2
GrannomHatch
2
2
Large StoneflyHatch
2
3
2
Yellow SallyHatch
2
3
2

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

Ranked for today
Brown Trout fly box
Permits & access
Permit required — see local rules.
  • Corse-du-Sud regulations
  • Carte de pêche required
  • No-kill development active.
What's coming
Plan ahead
5-day outlook
Water here around 21°C. Nothing cooler within range — carry a thermometer.
Water quality (WFD)
  • EcologyGood
  • ChemicalUnknown

WFD classification · FRER39

The full read · show the working · for Brown Trout · confidence 80%
How the 19 is built — score × weight = contribution
Temperature11 × 28%3.1
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time55 × 13%7.2
Pressure80 × 7%5.6
Insect activity49 × 12%5.9
Limiting factor: Water temperature (21.3°C) is outside Brown Trout's preferred range (10–16°C)= 57
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitysurvey-backed invertebrate datasurvey
What would change the calculation
Cooler water — back toward the 10–16 °C ideal band — would lift the score and ease welfare.
The dawn and dusk windows score higher than the midday lull.
Directions
Seasons & zones
  • Trout 2nd Saturday of March3rd Sunday of September
Related guides
Booking & contacts