Freestone · Granite · Castilla y León, ES

Río Arlanzón

Río Arlanzón — Río Arlanzón a su paso por Burgos

The Arlanzón rises in the Sierra de la Demanda above Pineda de la Sierra and runs down through the upper valley before feeding the Burgos plain.

Today · Closed season
Frenchie
Forecast · Today
Closed season
Out of season. Try elsewhere.
45% projected
Today's fly
Frenchie
Frenchie
Conditions on the water · Today
Live gauge
Level
Rising
0.26 m
Lifting fast
Water temp3.6°C
ClarityUnfishable
Weather8°C
WindN 19 km/h
Pressure1014 hPa
Rain · recent40.1 mm
Rain · ahead9.1 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
4°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.
Hatch timeline · todayQuiet day

Low insect activity predicted today

Sub-surface · on the nymphunder the surface

Hatch predictions

Top nymph shown — see all 3 guilds as a supporter.

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 · November highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
1
Large Dark OliveHatch
1
2
2
1
Blue Winged OliveHatch
1
2
2
2
2
1
Autumn OliveHatch
1
2
1
Brown SedgeHatch
1
2
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 licence required
  • Pineda-area cotos require tramo permits
  • Sierra de la Demanda altitude means the season effectively starts later than the calendar opener.
What's coming
Plan ahead
5-day outlook
Other water nearby · 5
Río Arlanza
33 km
0
Brown trout
Río Revinuesa
56 km
0
Brown trout
Upper Río Duero
58 km
0
Brown trout
Río Ebro (Burgos — Las Merindades to Miranda)
62 km
0
Brown trout
Río Jerea
65 km
0
Brown trout
Gallery · 2
  1. Río Arlanzón — Río Arlanzón a su paso por Burgos
    Río Arlanzón a su paso por Burgos
  2. Terrain map of the venue
    Terrain map
About this water

The upper basin around Pineda is a well-managed Burgos trout system with established coto structure, fly-only/catch-and-release periods, and reliable mountain-water character. Strong granite headwaters; pair with the SAIH Duero EA508 gauge at Pineda de la Sierra for live conditions.

  • Granite
The full read · show the working · for Brown Trout · confidence 45%
How the 0 is built — score × weight = contribution
Temperature12 × 28%3.4
Flow41 × 22%9.0
Clarity15 × 18%2.7
Feeding Time45 × 13%5.9
Pressure80 × 7%5.6
Insect activity28 × 12%3.4
Limiting factor: Water temperature (3.9°C) is outside Brown Trout's preferred range (10–16°C)= 30
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitysurvey-backed invertebrate datasurvey
What would change the calculation
Warmer water — toward the 10–16 °C ideal band — would lift the temperature score.
A drop and clear would lift the flow and clarity scores.
The dawn and dusk windows score higher than the midday lull.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout Last Sunday of March → 31 July
Related guides
Pyrenees PlaybookSpanish riversEuro Nymphingsubsurface methods
Booking & contacts
At a glance

Río Arlanzón is a freestone river in Castilla y León, Spain. The catchment geology is recorded as granite, and the water sits at about 1,161 m above sea level. The river is described as roughly 121 km long. The species listed for this water is brown trout. The trout season is recorded as running from Last Sunday of March to 31 July. Best window recorded for anglers: May–early July is the prime fly-fishing window once snowmelt eases; April can be high and pushy on the Pineda reach. Core methods listed: dry fly; short-line nymph; ahogada wet. Level and flow data for this water is linked from the gauge “EA508 Arlanzón en Pineda de la Sierra (upper)”. Nearby waters in our listings include Río Arlanza at 33 km, Río Revinuesa at 56 km and Upper Río Duero at 58 km.