Freestone · Limestone · Castilla y León, ES

Upper Río Duero

Upper Río Duero terrain map

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

Poor · Brown Trout
Klinkhammer · 14-18
Closed season
Out of season. Plenty of other water available now.
Closed — confidence not applicable today.
What moved it
  • LevelDry recentlyNo gauge reading
  • Water temp19.1°C
  • ClarityClear
Today's fly
Klinkhammer
Klinkhammer14-18
High-confidence seasonal pick
Conditions on the water
Estimate
Level
Dry recently
No gauge reading
Water temp19.1°C
ClarityClear
Weather23°C
WindE 7 km/h
Pressure1017 hPa
Rain · recent0.4 mm
Rain · ahead0.0 mm

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

Water temperature for Brown Trout
Warm — slow
19°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 19.1°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 6am

Hatch predictions

Today's headline hatch shown — see all 4 active hatches hour by hour with Pro.

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Sub-surface · on the nymphunder the surface

Hatch predictions

See the full sub-surface read 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
1
GrannomHatch
2
2
Evening SedgeHatch
2
3
3
3
2
Large Dark OliveHatch
1
2
2
1
Iron BlueHatch
1
2
2
1

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
Water here around 19°C. Nothing cooler within range — carry a thermometer.
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 80%
How the 0 is built — score × weight = contribution
Temperature38 × 28%10.6
Flow60 × 22%13.2
Clarity95 × 18%17.1
Feeding Time80 × 13%10.4
Pressure80 × 7%5.6
Insect activity62 × 12%7.4
Conditions total= 64
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.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout Last Sunday of March → 31 July
Related guides
Pyrenees PlaybookSpanish riversEuro Nymphingsubsurface methods
Booking & contacts