Spate · Slate · Asturias, Spain

Río Esva (Canero system)

The Río Esva flowing through riparian woodland in the Hoces del Esva gorge, Asturias.
Contributor photo

Río Esva in the Hoces gorge

Ruta Botanica - CC BY-SA 3.0

The Esva (also known by its lower section name Canero) is a small, intimate western Asturian trout river flowing 36 km through slate moorlands and pastoral valleys to Oviedo Bay.

Fair · Brown Trout
Ignita CDC · 16-20
Fairlive now
A side-water session, not the main event
River steady at a fishable height. A patient day. Fish the cover and stay with it.
75% confidence
What moved it
  • Level0.58 mLast reading 3h ago
  • Water temp16.8°C
  • ClarityClear
Today’s fly
IC
Ignita CDC16-20
Upstream dry, on top
Conditions on the water
Live gauge
Level
Steady
0.58 m
lowspate
Water temp16.8°C
ClarityClear
Weather15°C
WindNE 3 km/h
Pressure1019 hPa
Rain · recent0.2 mm
Rain · ahead19.8 mm

Live readings — water temperature is an estimate where the gauge does not record it.

Water temperature for brown trout
Warm — slow
17°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
Good — water clarity is working for you, but insect activity is the limiting factor today.
Hatch timeline · todayPeak at 6pm

Hatch predictions

See the full hour-by-hour hatch timeline with Pro.

Start free trial

14-day free trial. Cancel anytime.

Sub-surface · on the nymphunder the surface

Hatch predictions

See the full sub-surface read with Pro.

Start free trial

14-day free trial. Cancel anytime.

Beyond the hatch · worth watchingambient prey

Hatch predictions

See what else is on the menu with Pro.

Start free trial

14-day free trial. Cancel anytime.

Evidence
Survey-backed · regionalHigh confidence

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

Through the year
0–3 scale · July highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Salmon runRun
1
2
2
1
Trout seasonSeason
1
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
Beats · 6
Brieves · 1.3 kmSorteo
Sorteo stretch — 100 m aguas abajo de la presa de Brieves to Pasarela de Luisín.
Beat detail
Sorteo (lottery) permit required
Upstream: 100 m aguas abajo de la presa de Brieves
Downstream: Pasarela de Luisín
Brieves beat map
Trevías · 0.8 kmSorteo
Sorteo stretch — Pasarela de Luisín to Cola del pozo de la Morena.
Beat detail
Sorteo (lottery) permit required
Upstream: Pasarela de Luisín
Downstream: Cola del pozo de la Morena
Trevías beat map
Cortina · 2.2 kmFree Tue/Wed/Sat
Free Tue/Wed/Sat stretch — 25 m aguas arriba de la cabecera del pozo el Campón to Banzao de Villar.
Beat detail
Free on Tue/Wed/Sat, sorteo on other days
Upstream: 25 m aguas arriba de la cabecera del pozo el Campón
Downstream: Banzao de Villar
Cortina beat map
Chamberí · 1.8 kmSorteo
Sorteo stretch — Banzao de Villar to Puente de Chamberí.
Beat detail
Sorteo (lottery) permit required
Upstream: Banzao de Villar
Downstream: Puente de Chamberí
Chamberí beat map
Piedra Blanca · 1.5 kmSorteo
Sorteo stretch — 50 m aguas abajo de la presa de Casielles to Puente de Canero.
Beat detail
Sorteo (lottery) permit required
Upstream: 50 m aguas abajo de la presa de Casielles
Downstream: Puente de Canero
Piedra Blanca beat map
Agüera · 1.8 kmTrout permit
Trout permit stretch — 50 m aguas abajo del Banzao de Electra del Esva to 50 m aguas abajo Puente Bustiello.
Beat detail
Daily permit required, keep within bag limits
Upstream: 50 m aguas abajo del Banzao de Electra del Esva
Downstream: 50 m aguas abajo Puente Bustiello
Agüera 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
Other water nearby · 5
Gallery · 5
  1. The Río Esva flowing through riparian woodland in the Hoces del Esva gorge, Asturias.
    Río Esva in the Hoces gorge
  2. The Río Esva flowing past the village of Agüera in the Valle de Paredes, Asturias.
    Río Esva at Agüera
  3. A wooden footbridge crossing the Río Esva amid dense riparian woodland in the Hoces gorge.
    Footbridge over the Río Esva
  4. Remains of an ancient stone weir across the Río Esva in the Hoces gorge, Asturias.
    Old weir on the Río Esva
  5. Terrain map of the venue
    Terrain map
About this water

The Esva (also known by its lower section name Canero) is a small, intimate western Asturian trout river flowing 36 km through slate moorlands and pastoral valleys to Oviedo Bay. Unlike the major salmon rivers, the Esva is a dedicated brown trout and sea trout stream — salmon are technically present but catches are negligible, and the river's character is pure trout water. The river's charm lies in its accessibility, modest scale, and consistent wild trout populations. The slate geology creates fast, clear runs with excellent holding water for trout; the short response time (3 hours) means the river comes into perfect fishing condition quickly after rain. Upper tributaries hold small, wild brown trout (15–20 cm); the middle river reaches support larger browns (25–35 cm) that respond to careful presentation. Sea trout run in May–July, entering from the estuary during high tides and evening light. The Esva is an excellent destination for anglers seeking to improve technical dry-fly and nymphing skills without the competitive pressure of salmon beats. Mayfly hatches (May–June), sedges, and terrestrials dominate; night fishing for sea trout is not allowed. The river is typically uncrowded; local knowledge from the village of Pravia (nearby) is helpful. Access is straightforward from roadside parking; but Asturian licence and local tramo rules still need checking. Budget fishing at its best — a river that rewards patient observation and accurate casting. Atlantic salmon stocks are under serious conservation pressure, and where salmon are present the 2026 cupo permits one fish per angler per year; any further fish must be released.

Under the surface

The Esva runs from slate country through partly confined and pool-riffle sequences down roughly 60 kilometres to the sea at Navia province border. The upper reaches drop through step-pool pocket water on Cantabrian slate and quartzite; the tributaries feed the main river with that particular amber-toned spate-responsive character that slate country gives. The middle Esva opens into partly-confined pool-riffle on cobble and gravel emerging from the slate. The pools have depth and character; they're products of a river that's still responding to the landscape, not yet settled into the flattened patterns of lower river reaches. The amber colour persists — that's the signature of slate-country rivers. Watch the upper pocket water where the slate slabs cluster; the foothold is insecure and the wading demands full attention.

Wading: Slick slate and quartzite slabs in pocket water and gorge margins

  • Slate
  • Partly confined
  • Step pool
  • Bedrock gorge
Water quality (WFD)
  • EcologyGood
  • ChemicalUnknown

WFD classification · ES018MSPFES200MAR001770

The full read · show the working · for brown trout · confidence 75%
How the 63 is built — score × weight = contribution
Temperature81 × 28%22.7
Flow40 × 22%8.8
Clarity95 × 18%17.1
Feeding Time40 × 13%5.2
Pressure80 × 7%5.6
Insect activity27 × 12%3.2
Conditions total= 63
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitysurvey-backed invertebrate datasurvey
What would change the calculation
The dawn and dusk windows score higher than the midday lull.
Directions
Seasons & zones
  • SalmonThird Saturday of April → 15 July

    2026 season: opens 18 April. Bag limit reduced to 1 fish per angler per year (was 2 per season). 60 minutes less daily fishing time. Cupo: 1 salmon per day, 1 per season (kill limit). Check river-specific coto rules, vedados, and tackle restrictions before fishing. Esva basin quota for 2026: 5 salmon total.

  • TroutThird Sunday of March → 15 August
4 zones — different rules apply
  • Coto salmonero

    Main Esva salmon beats: Brieves, Trevías, Chamberí, Piedra Blanca (all salmonero tradicional)

    • Salmon: Third Saturday of April → 15 July · 1 per day, 1 per season (kill limit)
    • Sea trout: follows Trout
    • Trout: Third Sunday of May → 15 August
  • Coto parcial

    Cortina coto parcial — middle Esva

    • Salmon: Third Saturday of April → 15 July · 1 per day, 1 per season (kill limit)
    • Sea trout: follows Trout
    • Trout: Third Sunday of March → 15 August
  • Coto truchero

    Esva trout cotos: Agüera, La Central, Paredes, Restiello, La Chanona — upper/middle Esva

    • Sea trout: follows Trout
    • Trout: Third Sunday of March → 15 August
  • Zona libre

    Non-coto stretches of the Esva — free-access trout water

    • Sea trout: follows Trout
    • Trout: Third Sunday of March → 15 August

Sea trout: Variable seasonal (2026) — Western Asturias spate river — reo and salmon on a clean granite-peat system. Sea trout present from June on rising water. Short response time after rain, brief windows. Night fishing restricted per Asturian regional schedule.

Salmon: Heritage only (2026) — Heritage Asturian salmon river — small slate-and-pasture western Asturian river that has historically held salmon but is no longer a viable salmon fishing destination. Listed as 'historic'. Brown trout fishing remains the primary proposition; sea trout interest is modest.

Related guides
Booking & contacts