Spate · Mixed · Asturias, Spain

Río Aller

The Río Aller, a gravel-bedded river lined with trees, flowing through a green valley near Bustiello, Asturias, Spain.
Today · Closed season
Black Gnat
Forecast · Today
Closed season
Out of season. Plenty of other water available now.
90% projected
Today's fly
Black Gnat
Black Gnat
Conditions on the water · Today
Live gauge
Level
Steady
0.17 m
lowspate
Water temp17.3°C
ClarityClear
Weather17°C
WindN 9 km/h
Pressure1018 hPa
Rain · recent0.9 mm
Rain · ahead2.6 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
17°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
Water at 19.1°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 12pm

12pm(now) — Heather Fly

Stage: Terrestrials on topApproach: Dry flyActivity: 95%
Also:Reed Smut72%Cinnamon Sedge55%Autumn Dun34%
Peak emergence window11 food groups active

Peak activity at 12pm — Heather Fly (Heather Fly, Peak emergence window)

Sub-surface · on the nymphunder the surface

Hatch predictions

Top nymph shown — see all 3 guilds with Pro.

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Beyond the hatch · worth watchingambient prey(1)

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Evidence
Survey-backed · regionalHigh 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
1
March BrownHatch
2
3
2
Late March BrownHatch
2
3
2
Large Brook DunHatch
2
3
2
Large StoneflyHatch
2
3
2

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

Ranked for today
Brown Trout fly box
Beats · 2
Aller · 5.2 kmTrout permit
Trout permit stretch — Puente La Barraca en Collanzo to Puente de Bello.
Beat detail
Daily permit required, keep within bag limits
Upstream: Puente La Barraca en Collanzo
Downstream: Puente de Bello
Aller beat map
San Isidro · 3.8 kmTrout permit
Trout permit stretch — Puente de los Gallegos to Puente de Llanos.
Beat detail
Daily permit required, keep within bag limits
Upstream: Puente de los Gallegos
Downstream: Puente de Llanos
San Isidro beat map
Permits & access
Free state water
State rod licence required for trout / salmon as applicable.
  • Se requiere licencia de pesca asturiana
  • Comprueba la normativa local de trucha — algunos tramos pueden ser vedados.
What's coming
Plan ahead
5-day outlook
Water here around 19°C. Nothing cooler within range — carry a thermometer.
Gallery · 2
  1. The Río Aller, a gravel-bedded river lined with trees, flowing through a green valley near Bustiello, Asturias, Spain.
    Río Aller
  2. Terrain map of the venue
    Terrain map
The full read · show the working · for Brown Trout · confidence 80%
How the 0 is built — score × weight = contribution
Temperature23 × 28%6.4
Flow15 × 22%3.3
Clarity95 × 18%17.1
Feeding Time55 × 13%7.2
Pressure80 × 7%5.6
Insect activity29 × 12%3.5
Limiting factor: River is stable — Brown Trout prefers medium flow= 43
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.
A drop and clear would lift the flow and clarity scores.
The dawn and dusk windows score higher than the midday lull.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout Third Sunday of May → 15 August

    The Aller feeds the Caudal, itself a Nalón tributary joining well above Puente Peñaflor (Grado) — the Nalón's salmon-zone limit — so it sits in the mountain-zone tributary network. Mountain-zone trout (zona de alta montaña): opens Third Sunday of May, not the general 15 March, minimum size 17cm (vs. 19cm general). Asturian regulation classifies any tributary joining above a salmon river's designated zone-limit point as alta montaña water. Inferred here from confluence position, not a verified lookup against the official cotos map (pescafluvial.asturias.es) — confirm before treating as final.

Related guides
Pyrenees PlaybookSpanish riversEuro Nymphingsubsurface methods
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