Spate · Limestone · Asturias, Spain

Río Güeña

Río Güeña venue image

The Güeña is a charming limestone tributary flowing to the Sella at medieval Cangas de Onís.

Marginal · Brown Trout
Ignita CDC · 16-20
Marginallive now
Slow going — pick your moments
River temperature is the limiting factor today, not the flow. Fish dawn or dusk if you go at all, and handle everything with extra care.
80% confidence
What moved it
  • Level0.37 m
  • Water temp18.6°C
  • ClarityClear
Today's fly
IC
Ignita CDC16-20
Upstream dry, on top
Conditions on the water
Live gauge
Level
Steady
0.37 m
lowspate
Water temp18.6°C
ClarityClear
Weather21°C
WindW 9 km/h
Pressure1020 hPa
Rain · recent0.0 mm
Rain · ahead6.7 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
19°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 18.6°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

Top nymph shown — see all 2 guilds 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 · 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
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
Beats · 2
Güeña · 3.3 kmTrout permit
Trout permit stretch — Puente de madera junto a confluencia del Covadonga to Puente Cortijo la Gargantiella.
Beat detail
Daily permit required, keep within bag limits
Upstream: Puente de madera junto a confluencia del Covadonga
Downstream: Puente Cortijo la Gargantiella
Güeña beat map
Cangas de Onis · 1.4 kmC&R trout
C&R trout stretch — Puente Cortijo la Gargantiella to Confluencia con el Sella.
Beat detail
Daily permit required, all fish returned
Upstream: Puente Cortijo la Gargantiella
Downstream: Confluencia con el Sella
Cangas de Onis beat map
Permits & access
Free state water
State rod licence required for trout / salmon as applicable.
  • Asturian fishing licence required
  • In 2026 many trout waters run to 15 August, but salmon zones, mountain zones, tramos sin muerte, and border stretches can differ
  • Check local coto and tramo rules before fishing.
What's coming
Plan ahead
5-day outlook
Cooler water nearby · 2
Water here around 19°C — probably warm enough to stress Brown Trout . These are likely cooler.
Gallery · 1
  1. Terrain map of the venue
    Terrain map
About this water

The Güeña is a charming limestone tributary flowing to the Sella at medieval Cangas de Onís. Gin-clear water and pale stone pools hold wild browns (12–24 cm) that respond to careful presentation. The 3-hour spate response means quick transition to perfect fishing height. Mayfly and olive hatches May–June; sedges and terrestrials work in summer. Evening sessions in low water reward patience. Usually uncrowded, but Asturian licence and local tramo rules still apply. A river where precision casting and observation are rewarded with consistent contact.

Under the surface

The Güeña descends from high slate to arrive into the Sella from the east below Cangas de Onís. The river is steep, responsive, and slate-characterized throughout its course. The upper reaches are step-pool pocket water through Cantabrian slate; the descent is rapid and the response to rain immediate. The middle Güeña opens slightly but maintains its spate character — responsive, amber, belonging fully to the slate-country network. The pools are briefer than on larger rivers, the riffle sequences more continuous. By the time the Güeña arrives into the Sella's limestone country, it's already contributed its amber tone to the blended water. The wading demands attention throughout; the upper pocket water is particularly insecure. But the river's spate character and slate signature make it distinctive among Solana tributaries.

Wading: Polished wet limestone pavement

Hatches & food

In the mountain-to-sea trout rivers of Asturias, olives and other mayflies do much of the work in spring whenever levels and colour allow, followed by strong evening caddis and steady buzzer life through early and mid-summer, with terrestrials and mixed surface food from wooded, pastoral banks rounding out the diet whenever flows drop back into safe wading range.

  • Limestone
  • Partly confined
  • Step pool
  • Pool riffle
Water quality (WFD)
  • EcologyGood
  • ChemicalUnknown

WFD classification · ES018MSPFES142MAR000750

The full read · show the working · for Brown Trout · confidence 80%
How the 36 is built — score × weight = contribution
Temperature46 × 28%12.9
Flow40 × 22%8.8
Clarity95 × 18%17.1
Feeding Time55 × 13%7.2
Pressure80 × 7%5.6
Insect activity50 × 12%6.0
Conditions total= 58
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.
Related guides
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