Stillwater · Limestone · Asturias / Morcín–Riosa, ES

Embalse de los Alfilorios

Embalse de los Alfilorios terrain map

Alfilorios is a small thing with a complicated job: it supplies Oviedo with drinking water and, since 2020, doubles as a trout coto — the sort of pragmatic arrangement Asturias does rather well.

Fair · Trout
Griffith's Gnat · 18-22
Fairlive now
Reasonable autumn fishing likely at Embalse de los Alfilorios
Good wave on — drift country. A useful wave. Work the productive shore.
56% confidence

This is peak season for Embalse de los Alfilorios, though today's conditions aren't quite ideal. Worth fishing — the timing is right even if the weather isn't perfect.

What moved it
  • WindS 6 km/hLight breeze
Today's fly
Griffith's Gnat
Griffith's Gnat18-22
Upstream dry, on top
Conditions on the water
Estimate
Wind
Light breeze
S 6 km/h
N
S
from the south
WaveRipple
Water temp11.8°C
Air temp13°C
CloudOvercast
Pressure1022 hPa
Rain · recent0.0 mm

No gauge on this water — readings are regional estimates from weather, not a live gauge.

Reservoir levelas of 31 Aug
66% 10-yr norm
Steady
50% full
Low & steady
-16 ptsvs seasonal norm
0 ptsvs last year
0 ptsthis week
Below seasonal norm but level steady — fish should be settled to the new shoreline.
How to fish it · for Trout
When
March to August (coto open season). Quiet weekday permits are easiest to come by.
Where
Start with CDC F-Fly (Black) (18-22) on a As per local method. If that does not produce, switch depth or speed before changing the pattern entirely.
The plan
Plan A

Start with CDC F-Fly (Black) (18-22) on a As per local method. If that does not produce, switch depth or speed before changing the pattern entirely.

Plan B

A fry-imitating pattern stripped through the margins can save a blank in autumn.

Watch for

Keep an eye on changing conditions — wind shifts and cloud breaks can trigger short feeding spells.

Either bank or boat

Good ripple suits both bank and boat. Bank: work inflows, dam walls, and points. Boat: broadside drift covering wind lanes.

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)

Hatch predictions

Top prey shown — see all 5 with Pro.

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Through the year
0–3 scale · September highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Mayfly (Green Drake)Hatch
2
2
Daddy Long LegsHatch
2
3
2
DuckflyHatch
2
2
Silverhorns & LonghornsHatch
2
3
3
3
2

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

Ranked for today
Trout fly box
Permits & access
Permit required — see local rules.
  • Asturias licence + Alfilorios coto permit required
  • Bank only — no boats (drinking-water reservoir)
  • Limited to 3 anglers/day and 3 trout/angler/day; sin muerte once the cup is reached
  • Stocked with adult native brown trout.
What's coming
Plan ahead
5-day outlook
Condition match
85%
Cloud50%
Wind100%
Temp100%

Conditions are ideal for Embalse de los Alfilorios — wind, cloud and temperature all line up.

Other water nearby · 5
About this water

Alfilorios is a small thing with a complicated job: it supplies Oviedo with drinking water and, since 2020, doubles as a trout coto — the sort of pragmatic arrangement Asturias does rather well. The fishing nearly didn't survive. The original stock wore thin faster than anyone had budgeted for, and the answer was to put back adult native brown trout, fish too old for the rivers, to keep the place ticking over. It is bank fishing only, three rods a day and three fish, so you fish it slowly and you fish it properly. Nymph the margins, watch for an evening rise, and don't expect a crowd. For a reservoir that exists to fill taps, it fishes with surprising charm.

  • Reservoir
  • Limestone
Why this score
  • Wind conditions (ripple) closely match what this water fishes best in.
  • Temperature (cool) is in the sweet spot for autumn fishing.
  • Below seasonal norm but level steady — fish should be settled to the new shoreline.
Related guides
Booking & contacts