Spate · Granite · Galicia (Pontevedra, ES

Río Deza

Río Deza — Ponte do Demo / Puente del Diablo / Devil's Bridge

A southern Ulla tributary draining the Deza valley between Lalín and Silleda.

Today · Closed season
Black Gnat
Forecast · Today
Closed season
Out of season. Plenty of other water available now.
75% projected
Today's fly
Black Gnat
Black Gnat
Conditions on the water · Today
Live gauge
Level
Steady
1.26 m
Water temp17.1°C
ClarityClear
Weather22°C
WindN 9 km/h
Pressure1023 hPa
Rain · recent0.0 mm
Rain · ahead0.0 mm

The nearest gauge doesn't record temperatures, so we've estimated it — defer to the river keeper's advice.

Water temperature for Brown Trout
Warm — slow
17°C est.ideal 1016°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 18°C — above the brown trout caution line (18°C). Fish dawn or dusk only. Land it fast, wet hands, no air shots.
Hatch timeline · todayPeak at 12pm

12pm(now) Heather Fly

Stage: Terrestrials on topApproach: Dry flyActivity: 95%
Also:Reed Smut89%Cinnamon Sedge50%Autumn Dun37%
Peak emergence windowWeather boost10 food groups active

Peak activity at 12pm — Heather Fly (Heather Fly, Peak emergence window)

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 3 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 · September highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Sea trout runRun
1
2
1
Trout seasonSeason
1
2
1
March BrownHatch
2
3
2
Late March BrownHatch
2
3
2
Large Brook DunHatch
2
3
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
Permits & access
Permit required — see local rules.
  • Galician licence required
  • Salmon fishing prohibited (Xunta 2026 emergency decree).
What's coming
Plan ahead
5-day outlook
Water here around 18°C. Nothing cooler within range — carry a thermometer.
Gallery · 2
  1. Río Deza — Ponte do Demo / Puente del Diablo / Devil's Bridge
    Ponte do Demo / Puente del Diablo / Devil's Bridge
  2. Terrain map of the venue
    Terrain map
About this water

A southern Ulla tributary draining the Deza valley between Lalín and Silleda. Heritage salmon tributary — salmon fishing banned in Galicia 2026 — but a steady wild brown trout and reo river in its own right. The middle reaches around Trasdeza and the Deza forest hold the most interest, with classic Galician granite freestone structure and partial canopy keeping summer water temperatures manageable.

Hatches & food

In Galicia's Atlantic trout rivers, resident browns feed through a spring build-up of olives and other up-wings into a long summer of caddis and small buzzers, with frequent spates and cool water keeping fish active; terrestrials from lush banks and meadows become important once levels settle and the banks green up.

  • Granite
The full read · show the working · for Brown Trout · confidence 80%
How the 0 is built — score × weight = contribution
Temperature42 × 28%11.8
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time60 × 13%7.8
Pressure80 × 7%5.6
Insect activity65 × 12%7.8
Conditions total= 68
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
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
Seasons & zones
  • Sea trout 1 May31 July
  • Trout 1 May31 July

Salmon: Banned (2026) — Galicia 2026 salmon closure — Xunta emergency decree.

Related guides
Booking & contacts