Stillwater · Mixed · Mid-Wales / Powys

Elan Valley (Rhayader)

Claerwen Reservoir with its surrounding mountain ridges reflected in still water.

Elan Valley is more than one reservoir — it's a managed cascade of waters in a spectacular moorland valley, overseen by the Rhayader and Elan Valley Angling Association.

Marginal · Trout
Olive Damsel · 10-12
A patient day, if you fancy it
Water temperature is the limiting factor today, not the wave. Fish dawn or dusk if you go at all, and handle everything with extra care.
44% confidence
limited data
What moved it
  • WindSW 13 km/hGentle breeze
Today's fly
OD
Olive Damsel10-12
Retrieve, sub-surface
Conditions on the water
Live gauge
Wind
Gentle breeze
SW 13 km/h
N
SW
from the south-west
Wave20 cm ripple
Water temp
Air temp27°C
CloudOvercast
Pressure
Rain · recent0.0 mm

Some readings unavailable — check directly before fishing.

How to fish it · for Trout
When
Conditions are not ideal but fishable at Elan Valley (Rhayader). The ripple should help fish move and feed more confidently. Very warm conditions — trout have a narrower safe zone of cool, oxygen-rich water. Fish only at first light or last light, use barbless hooks, keep fish in the water during release, and stop if fish struggle to recover.
Where
Start with Diawl Bach (12-14) — on the bob / top dropper — slow figure-of-eight retrieve. As evening approaches, switch to dries or emergers if you see surface activity.
The plan
Plan A

Start with Diawl Bach (12-14) — on the bob / top dropper — slow figure-of-eight retrieve. As evening approaches, switch to dries or emergers if you see surface activity.

Plan B

Fish early and late, try deeper during the heat of the day with a fast-sinking line.

Watch for

Evening tends to be the best period in summer — stay late if you can for a sedge or spinner fall.

Either bank or boat

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

Beyond the hatch · worth watchingambient prey

Hatch predictions

Top prey shown — see all 3 with Pro.

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Through the year
0–3 scale · July highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
2
1
Daphnia SwarmHatch
2
3
3
3
2
Daddy Long LegsHatch
2
3
2
Lake OliveHatch
2
3
3
3
3
3
2
Silverhorns & LonghornsHatch
1
2
2
2
1

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

Ranked for today
Trout fly box

Boat-friendly, competition-influenced, often wind-driven, with strong top-of-water periods but also classic deep searching and washing-line phases.

What's coming
Plan ahead
5-day outlook
Condition match
49%
Cloud50%
Wind65%
Temp25%

Conditions are away from Elan Valley (Rhayader)'s sweet spot — it usually fishes best in ripple wind with cloud skies.

Other water nearby · 5
Gallery · 2
  1. Claerwen Reservoir with its surrounding mountain ridges reflected in still water.
    Claerwen Reservoir and mountains
  2. Terrain map of the venue
    Terrain map
About this water

Elan Valley is more than one reservoir — it's a managed cascade of waters in a spectacular moorland valley, overseen by the Rhayader and Elan Valley Angling Association. Multiple lakes here (Caban Coch, Garreg-ddu, Pen-y-garreg, Claerwen) offer layered fishing from April through October. The limestone and moorland geology produces reliable hatches and fertile food. The valley setting is magnificent — you're fishing some of Wales's most dramatic scenery without sacrificing access. Spring and early summer produce the best sport; autumn can be productive after a build-up of cold nights. This is pilgrimage water for Welsh fly fishers — plan to spend days here, not hours.

  • Reservoir
  • Mixed
Water quality (WFD)
  • EcologyGood
  • ChemicalUnknown

NRW (Wales) · UKGB110064048350

Why this score
  • Damsel Nymph is in its seasonal window, boosting the chance of targeted feeding.
Directions
Seasons & zones
  • Trout 15 March5 October
Related guides
Casting instructors near here
Booking & contacts
Clubs & associations