Spate · Old Red Sandstone · Wales / Brecon Beacons (Tawe tributary)

Afon Twrch

The Afon Twrch, a small upland river, winding through a moorland valley in the Brecon Beacons

The Twrch is the main tributary of the Tawe — small, double-bank, and known to those who know it as one of the best-kept brown trout secrets in south Wales.

Poor · Brown Trout
Pheasant Tail Nymph · 14-16
Poorlive now
Not the day for it
River temperature is the limiting factor today, not the flow. This is not the day to push it. Check the thermal advice above before you head out.
90% confidence
What moved it
  • LevelProxyvia Cothi
  • Water temp22.0°C
  • ClarityClear
Today's fly
Pheasant Tail Nymph
Pheasant Tail Nymph14-16
Upstream, sub-surface
Conditions on the water
Proxy gauge
Level
Steady
Proxy
via Cothi
Water temp22.0°C
ClarityClear
Weather28°C
WindW 12 km/h
Pressure1021 hPa
Rain · recent0.0 mm
Rain · ahead1.0 mm

No gauge on this water — conditions are inferred from Cothi. The trend transfers, the absolute level does not.

Water temperature for Brown Trout
Warm — slow
22°C est.ideal 10–16°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
Water at 22°C. This is the line where catch-and-release kills brown trout. Do not fish for them today.
Hatch timeline · todayPeak at 6pm

Hatch predictions

Today's headline hatch shown — see all 8 active hatches hour by hour with Pro.

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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

Hatch predictions

Top prey shown — see all 2 with Pro.

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Evidence
Survey-backed · regionalHigh confidence

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

Through the year
0–3 scale · August highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
1
Daddy Long LegsHatch
2
3
2
March BrownHatch
2
3
2
GrannomHatch
2
2
Large StoneflyHatch
2
3
2

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

Ranked for today
Brown Trout fly box

Spider-heavy and practical. Strong tradition of North Country soft hackles, useful nymphing, and simple dry flies when fish rise properly.

Beats · 1
Afon Twrch — Beats 1 & 2 via Fishing PassportAccess varies
Two short day-ticket beats on the Twrch — Beat 1 (¾ mile) and Beat 2 (½ mile) — both double bank.
What's coming
Plan ahead
5-day outlook
Water here around 22°C. Nothing cooler within range — carry a thermometer.
Gallery · 3
  1. The Afon Twrch, a small upland river, winding through a moorland valley in the Brecon Beacons
    The Afon Twrch winding through moorland above Ystradgynlais
  2. River Twrch looking south downstream from the side of Pen yr Helyg
    River Twrch looking south downstream from the side of Pen yr Helyg
  3. Terrain map of the venue
    Terrain map
About this water

The Twrch is the main tributary of the Tawe — small, double-bank, and known to those who know it as one of the best-kept brown trout secrets in south Wales. Two short Passport beats (¾ mile and ½ mile), seventeen quid a day, five for juniors. The kind of small Brecon Beacons spate water that rewards quiet wading and small flies. The Tawe gets the headlines; the Twrch quietly fishes.

  • Old red sandstone
The full read · show the working · for Brown Trout · confidence 90%
How the 12 is built — score × weight = contribution
Temperature6 × 28%1.7
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time60 × 13%7.8
Pressure80 × 7%5.6
Insect activity58 × 12%7.0
Limiting factor: Water temperature (22°C) is outside Brown Trout's preferred range (10–16°C)= 57
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via Cothiproxy
Prey activitysurvey-backed invertebrate datasurvey
What would change the calculation
Cooler water — back toward the 10–16 °C ideal band — would lift the score and ease welfare.
The dawn and dusk windows score higher than the midday lull.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout 3 March → 30 September
Related guides
Yorkshire & SpidersNorth Country methodsEuro Nymphingsubsurface methods
Casting instructors near here
Booking & contacts