El río Duero, cerca de su nacimiento en Duruelo de la Sierra, Soria

Freestone · Limestone · Castilla y León, ES

Upper Río Duero

The upper Duero navigates beautiful limestone plateau country above Soria — 40 km of clear water and productive brown trout habitat.

Agustín Sandoval - CC BY-SA 4.0

Forecast · Tomorrow

Closed season

Out of season. Try elsewhere.

45% projected

Notify when prime

Today's fly

Frenchie

Rules at a glance

Public water
Licence required

Forecast

Conditions on the water · Tomorrow

Live gauge

Trends shown where the gauge supports them

Level

Rising

0.08 m

Lifting fast

Water temp

6.6°C

coldwarm

Clarity

Very coloured

Colouring up

Weather

14°C

Overcast

Wind

N 14 km/h

calmblown out

Pressure

1025 hPa

lowhigh

Rain · recent

1.7 mm

dryspate risk

Rain · ahead

0.9 mm

dryspate risk

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

Water temperature for Brown Trout

Cool — slow

7°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.

Likely species

Mayflies

Angler's CurseMost likelyLower confidenceNearest relative
#20–22 · Spinner
Go tiny: 20-22 spent spinner, single fly, long tippet.

Caddisflies

Net-spinning caddisMost likelyLower confidenceNearest relative
#12–14–16 · Pupa
Widespread riffle net-spinner; evening emergence.
CapererAlso possibleLower confidence
#10–12 · Adult
Big autumn sedge; fish dry at last light.
Green SedgeAlso possibleLower confidenceNearest relative
#10–12–14–16 · Nymph
Free-living green caddis larva; fast stony riffles.

Gammarids

Freshwater shrimpMost likelyLower confidenceNearest relative
#10–14 · Adult
No hatch? Dead-drift a shrimp deep — the year-round standby.

Hatch timeline · tomorrowPeak at 11am

12pm(now) — Autumn Needle Fly

Stage: Creeping nymphsApproach: Heavy nymphActivity: 25%

Also:Black Midge24%

Peak emergence windowWeather boost3 food groups active

Peak activity at 11am — Autumn Needle Fly (Autumn Needle Fly, Peak emergence window)

Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Supporters see what else is on the menu.

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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

Trout season

Evening Sedge

Large Dark Olive

Iron Blue

Blue Winged Olive

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.

Castilla y León fishing licence required
Many premium trout waters use the Junta's tramo-based management system, including EDE sections, so check the exact section and current rules before travel.

What's coming

Plan ahead

5-day outlook

Other water nearby · 5

Gallery · 2

Terrain map

About this water

The upper Duero navigates beautiful limestone plateau country above Soria — 40 km of clear water and productive brown trout habitat. Classic high-altitude freestone fishing with excellent insect diversity and selectively rising fish. Strong limestone mayfly hatches (Baetis in spring, Ephemerella in early summer) support consistent dry-fly opportunity. Evening spinner falls from May onwards reward technical work.

Limestone

Water quality (WFD)

Ecology: Bad
Chemical: Unknown

What this classification means

WFD ecological status Moderate → Bad corrected to EEA WISE 2022 (3rd RBMP) classification for waterbody ES020MSPF000000306 (was a stale earlier-cycle value). Source: EEA WISE SWB_SurfaceWaterBody (discodata.eea.europa.eu), verified 2026-06-18.

WFD classification · ES020MSPF000000306

The full read · show the working · for Brown Trout · confidence 75%

How the 0 is built — score × weight = contribution

Temperature100 × 28%28.0

Flow40 × 22%8.8

Clarity95 × 18%17.1

Feeding Time45 × 13%5.9

Pressure80 × 7%5.6

Insect activity35 × 12%4.2

Conditions total= 70

Can you trust it?

Water temperatureair-to-water estimateestimated

Level / flowon-river gaugeobserved

Prey activitysurvey-backed invertebrate datasurvey

What would change the calculation

The dawn and dusk windows score higher than the midday lull.

Directions

Apple Maps Google Maps

Seasons & zones

Trout Last Sunday of March → 31 July

Related guides

Booking & contacts

Permits & access

Junta de CyL — Permisos de Pesca
Castilla y León fishing licence and coto permits

Freestone · Limestone · Castilla y León, ES

Upper Río Duero

Contributor photo

Agustín Sandoval - CC BY-SA 4.0

The upper Duero navigates beautiful limestone plateau country above Soria — 40 km of clear water and productive brown trout habitat.

Tomorrow · Closed season

Frenchie

Forecast · Tomorrow

Closed season

Out of season. Try elsewhere.

45% projected

Notify when prime

Today's fly

Frenchie

Conditions on the water · Tomorrow

Live gauge

Level

Rising

0.08 m

Lifting fast

Water temp6.6°C

ClarityVery coloured

Weather14°C

WindN 14 km/h

Pressure1025 hPa

Rain · recent1.7 mm

Rain · ahead0.9 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

Cool — slow

7°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.

Likely species

Mayflies

Angler's CurseMost likelyLower confidenceNearest relative
#20–22 · Spinner
Go tiny: 20-22 spent spinner, single fly, long tippet.

Caddisflies

Net-spinning caddisMost likelyLower confidenceNearest relative
#12–14–16 · Pupa
Widespread riffle net-spinner; evening emergence.
CapererAlso possibleLower confidence
#10–12 · Adult
Big autumn sedge; fish dry at last light.
Green SedgeAlso possibleLower confidenceNearest relative
#10–12–14–16 · Nymph
Free-living green caddis larva; fast stony riffles.

Gammarids

Freshwater shrimpMost likelyLower confidenceNearest relative
#10–14 · Adult
No hatch? Dead-drift a shrimp deep — the year-round standby.

Hatch timeline · tomorrowPeak at 11am

12pm(now) — Autumn Needle Fly

Stage: Creeping nymphsApproach: Heavy nymphActivity: 25%

Also:Black Midge24%

Peak emergence windowWeather boost3 food groups active

Peak activity at 11am — Autumn Needle Fly (Autumn Needle Fly, Peak emergence window)

Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Supporters see what else is on the menu.

Start free trial

14-day free trial. Cancel anytime.

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

Trout season

Evening Sedge

Large Dark Olive

Iron Blue

Blue Winged Olive

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.

Castilla y León fishing licence required
Many premium trout waters use the Junta's tramo-based management system, including EDE sections, so check the exact section and current rules before travel.

What's coming

Plan ahead

5-day outlook

Other water nearby · 5

Embalse de la Cuerda del Pozo