Stillwater · Limestone · North Wales / Powys, GB-WLS

Lake Vyrnwy

Broad view of Lake Vyrnwy reservoir with calm water, wooded hillsides, and the shoreline stretching into the distance.

Lake Vyrnwy is the reservoir that made fly fishing accessible to the ordinary angler.

Closed season · Rainbow
Booby · 10–12
Closed season
Season reopens 15 March. Try elsewhere.
Closed — confidence not applicable today.

Lake Vyrnwy is often best in spring through autumn.

What moved it
  • WindSW 10 km/hLight breeze
Today's fly
Booby
Booby10–12
Washing-line, sub-surface
Conditions on the water
Estimate
Wind
Light breeze
SW 10 km/h
N
SW
from the south-west
WaveRipple
Water temp8.8°C
Air temp0°C
CloudBroken
Pressure1017 hPa
Rain · recent0.0 mm

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

How to fish it · for Rainbow
When
Current conditions suit Lake Vyrnwy well for winter tactics. The ripple should help fish move and feed more confidently.
Where
Start with Autumn Buzzer (12–14) — on the bob / top dropper — slow figure-of-eight retrieve. Rainbows respond to more active retrieves — try short strips between pauses. If that does not produce, switch depth or speed before changing the pattern entirely.
The plan
Plan A

Start with Autumn Buzzer (12–14) — on the bob / top dropper — slow figure-of-eight retrieve. Rainbows respond to more active retrieves — try short strips between pauses. If that does not produce, switch depth or speed before changing the pattern entirely.

Plan B

Slow down everything. A booby on a fast-sinking line, left static, can pick up deep fish.

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 2 guilds as a supporter.

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Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Top prey shown — see all 5 as a supporter.

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Through the year
0–3 scale · November highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
2
1
Reservoir BuzzerHatch
2
3
3
3
3
3
2
Daphnia SwarmHatch
2
3
3
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.

Buzzer team todayfor the conditions now
Point
Black buzzer, orange thorax
Not in this water's box
#10
How to fish it
Intermediate line · let the breeze drift the team, then hang it 15–30 s

Fly recommendations

Point fly shown — supporters see the whole team, sizes and why.

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Ranked for today
Rainbow 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
79%
Cloud70%
Wind100%
Temp60%

A good match for Lake Vyrnwy — most conditions are close to what it fishes best in.

Other water nearby · 5
Llyn Coch Hwyad
12 km
Brown trout
Bala Lake (Llyn Tegid)
15 km
Brown trout · Pike · Perch
Llyn Gwyddior
15 km
Brown trout
Llyn Cwmprysor
27 km
Brown trout
Afon Eden (Welsh)
28 km
Brown trout
Gallery · 6
  1. Broad view of Lake Vyrnwy reservoir with calm water, wooded hillsides, and the shoreline stretching into the distance.
    Lake Vyrnwy reservoir
  2. The Victorian Gothic straining tower and approach bridge standing in Lake Vyrnwy, reservoir water surrounding it.
    Lake Vyrnwy straining tower
  3. The stone dam wall of Lake Vyrnwy with the reservoir impounded behind it and wooded hillsides on the far bank.
    Lake Vyrnwy dam and reservoir
  4. Elevated panoramic view over Lake Vyrnwy showing the dam, the straining tower, and the full length of the reservoir.
    Lake Vyrnwy from Craig garth-bwlch
  5. Drone aerial photograph over Lake Vyrnwy reservoir in autumn, the open water ringed by forested hillsides.
    Lake Vyrnwy from the air
  6. Terrain map of the venue
    Terrain map
About this water

Built in 1889, Vyrnwy has a long place in British stillwater fly-fishing. The water is fished from bank and boat, and the limestone geology produces reliable food patterns. Buzzers hatch from April, damsels from June, and sedges cloud the evening air through late summer. The valley setting and native woodland give it a wild, unhurried feel despite the managed access. This is a pilgrimage water — worth scheduling your life around.

Surface area
4.5 km² (1,121 acres)
Max depth
26 m (84 ft)
Length
7.6 km (4.7 mi)
Width
800 m (875 yd)
Area, max depth, length and width: Wikipedia, Lake Vyrnwy
  • Reservoir
  • Limestone
Water quality (WFD)
  • Ecology: Moderate
  • Chemical: Unknown
What this classification means

NRW WFD Cycle 3 (lake) — Llyn Efyrnwy / Lake Vyrnwy: Moderate ecological status. Re-tagged 2026-06-18 from a feeder-river reach to the reservoir's own lake waterbody. Source: NRW DataMapWales WFD Cycle 3 classification layer.

NRW (Wales) · GB30935568

Why this score
  • Wind conditions (ripple) closely match what this water fishes best in.
  • Reservoirs of this kind fish hard at this time of year.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout 15 March → 5 October
Related guides
Fly Fishing in North and Mid Walesfeatured in this guideBig Stillwater Playbookreservoir tacticsReservoir Entomologymatching the hatch
Casting instructors near here
Booking & contacts
Boards & regulators
At a glance

Lake Vyrnwy is a reservoir in North Wales / Powys. The catchment geology is recorded as limestone, and the water sits at about 229 m above sea level. Species listed for this water: brown trout and rainbow trout. The trout season is recorded as running from 15 March to 5 October. Best window recorded for anglers: April–June, September. Core methods listed: loch-style drift; bank nymph; dry fly (sedges/buzzers). Its Water Framework Directive ecological status is recorded as moderate. Nearby waters in our listings include Llyn Coch Hwyad at 12 km, Bala Lake (Llyn Tegid) at 15 km and Llyn Gwyddior at 15 km.