Stillwater · Mixed · Mid Wales / Carmarthenshire

Llyn Brianne

Llyn Brianne Reservoir from the western shore, open water toward the spillway with Tywi Forest on the far hillside.

Llyn Brianne is a great upland reservoir flooded into the headwaters of mid Wales, an acid catchment of peat and rock where the water runs soft and the wild brown trout run hard.

Fair · Rainbow
Coch-y-Bonddu Beetle · 10-14
A respectable few hours, if you choose your moments
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.
45% confidence
limited data

Llyn Brianne is often best in spring through autumn.

What moved it
  • WindW 9 km/hLight breeze
Today's fly
CY
Coch-y-Bonddu Beetle10-14
Upstream dry, on top
Conditions on the water
Live gauge
Wind
Light breeze
W 9 km/h
N
W
from the west
WaveRipple
Water temp—
Air temp26°C
CloudOvercast
Pressure—
Rain · recent0.0 mm

Some readings unavailable — check directly before fishing.

How to fish it · for Rainbow
When
The buzzers are on. Daddy longlegs may also come into play as the day warms. The ripple is helpful — fish should move onto the feed and a slow-drifted team or single wet will cover water well.
Where
Set up a broadside drift and cover the water systematically. Work a bushy searching pattern on the bob and drop a contrasting nymph on the point.
The plan
Plan A

Set up a broadside drift and cover the water systematically. Work a bushy searching pattern on the bob and drop a contrasting nymph on the point.

Plan B

If the main plan is not working, switch to a smaller, more imitative pattern fished slower and deeper. A change of drift angle can also make a difference.

Watch for

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

Boat — drift

A gentle ripple is ideal for drifting — broadside drift covering the wind lanes should be productive.

Sub-surface · on the nymphunder the surface

Hatch predictions

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Beyond the hatch · worth watchingambient prey

Hatch predictions

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Through the year
0–3 scale · August highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Daddy Long LegsHatch
2
3
2
Murrough (Great Red Sedge)Hatch
2
3
2
Black MidgeHatch
2
3
3
3
3
3
3
3
3
3
3
2
Lake OliveHatch
1
2
2
2
2
2
1

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

Ranked for today
Rainbow fly box

Traditional wild-trout llyn fishing. Wet flies and dabblers stay central, with buzzer, caddis, terrestrials and occasional small fry patterns becoming important as the season warms.

What's coming
Plan ahead
5-day outlook
Condition match
63%
Cloud50%
Wind100%
Temp25%

A reasonable day here, though temperature isn't quite in the sweet spot.

Other water nearby · 5
Llyn Berwyn
13 km
Brown trout
Llyn Carw
15 km
Brown trout
Usk Reservoir
17 km
Brown trout · Rainbow trout
Springwater Lakes
18 km
Brown trout · Rainbow trout
Llyn Gynon
19 km
Brown trout
Gallery · 5
  1. Llyn Brianne Reservoir from the western shore, open water toward the spillway with Tywi Forest on the far hillside.
    Llyn Brianne Reservoir
  2. View across the Afon Tywi arm of Llyn Brianne toward the dense Tywi Forest on the far shore.
    Llyn Brianne — the Tywi arm
  3. Broad landscape view of Llyn Brianne Reservoir looking north, open water in the foreground and moorland and woodland rising around.
    Llyn Brianne Reservoir
  4. Wide panoramic view of Llyn Brianne reservoir on a clear day, forested hills descending to the water.
    Llyn Brianne panorama
  5. Terrain map of the venue
    Terrain map
About this water

Llyn Brianne is a great upland reservoir flooded into the headwaters of mid Wales, an acid catchment of peat and rock where the water runs soft and the wild brown trout run hard. This is not a manicured day-ticket pond. It's a big, weather-beaten upland water where the fish are mostly small, dark, beautifully marked and entirely uninterested in being caught easily. The browns are wild and earn their living in lean water, with stocked fish added over the years to the mix. The reward isn't size, it's the place — bare hills, drifting cloud, and trout that have never seen anything soft in their lives. Fish a team of traditional Welsh wets across the wave from drifting boat or rocky bank, and on the right blustery day the offers come fast and savage. On the wrong day the wind simply wins.

  • Lake
  • Mixed
Why this score
  • Wind conditions (ripple) closely match what this water fishes best in.
  • Buzzers are in their seasonal window, boosting the chance of targeted feeding.
Related guides
Thermal Layers & Troutreading depth and temperatureEuro Nymphingsubsurface methods
Casting instructors near here
Booking & contacts