Crystal-clear limestone spring creek in the Cazorla-Segura-Las Villas Natural Park; superb wild brown trout; catch-and-release only.
- Limestone karst
Water temperature for brown trout
Warm — slow17°C est.ideal 10–16°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
Good — water clarity is working for you, but time of day is the limiting factor today.
Hatch timeline · todayQuiet day
Hatch predictions
Today's headline hatch shown — see all 8 active hatches hour by hour with Pro.
Start free trial14-day free trial. Cancel anytime.
Sub-surface · on the nymphunder the surface
Hatch predictions
See the full sub-surface read with Pro.
Start free trial14-day free trial. Cancel anytime.
Beyond the hatch · worth watchingambient prey
Hatch predictions
Top prey shown — see all 3 with Pro.
Start free trial14-day free trial. Cancel anytime.
Evidence
Records-basedModerate confidence
Based on species-occurrence records, not local invertebrate surveys.
Through the year
0–3 scale · July highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Brown SedgeHatch
2
3
2
Freshwater ShrimpHatch
2
3
3
3
3
3
3
3
3
3
3
2
Blue Winged OliveHatch
2
3
3
3
3
2
Mayfly (Green Drake)Hatch
2
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.
- Junta de Andalucía licence plus trout surcharge required
- Confirm the exact current coto status and any local method restrictions before travel.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gallery · 2
Río Castril Terrain map
About this water
The full read · show the working · for brown trout · confidence 75%
How the 72 is built — score × weight = contribution
Temperature86 × 28%24.1
Flow60 × 22%13.2
Clarity95 × 18%17.1
Feeding Time40 × 13%5.2
Pressure80 × 7%5.6
Insect activity60 × 12%7.2
Conditions total= 72
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.
Directions
Seasons & zones
- Troutdurante los periodos hábiles (check current BOJA) → during the designated open period
Related guides
Booking & contacts
Río Castril
Contributor photo
Río Castril
EstefaníaGQ - CC BY-SA 4.0
Crystal-clear limestone spring creek in the Cazorla-Segura-Las Villas Natural Park; superb wild brown trout; catch-and-release only.
Water temperature for brown trout
Warm — slow17°C est.ideal 10–16°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
Good — water clarity is working for you, but time of day is the limiting factor today.
Hatch timeline · todayQuiet day
Hatch predictions
Today's headline hatch shown — see all 8 active hatches hour by hour with Pro.
Start free trial14-day free trial. Cancel anytime.
Sub-surface · on the nymphunder the surface
Hatch predictions
See the full sub-surface read with Pro.
Start free trial14-day free trial. Cancel anytime.
Beyond the hatch · worth watchingambient prey
Hatch predictions
Top prey shown — see all 3 with Pro.
Start free trial14-day free trial. Cancel anytime.
Evidence
Records-basedModerate confidence
Based on species-occurrence records, not local invertebrate surveys.
Through the year
0–3 scale · July highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Brown SedgeHatch
2
3
2
Freshwater ShrimpHatch
2
3
3
3
3
3
3
3
3
3
3
2
Blue Winged OliveHatch
2
3
3
3
3
2
Mayfly (Green Drake)Hatch
2
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.
- Junta de Andalucía licence plus trout surcharge required
- Confirm the exact current coto status and any local method restrictions before travel.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Gallery · 2
Río Castril Terrain map
About this water
Crystal-clear limestone spring creek in the Cazorla-Segura-Las Villas Natural Park; superb wild brown trout; catch-and-release only.
- Limestone karst
The full read · show the working · for brown trout · confidence 75%
How the 72 is built — score × weight = contribution
Temperature86 × 28%24.1
Flow60 × 22%13.2
Clarity95 × 18%17.1
Feeding Time40 × 13%5.2
Pressure80 × 7%5.6
Insect activity60 × 12%7.2
Conditions total= 72
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.
Directions
Seasons & zones
- Troutdurante los periodos hábiles (check current BOJA) → during the designated open period
Related guides
Booking & contacts