Spring Fed · Limestone · Aragón, ES

Ríos Piedra, Mesa and upper Jalón (Calatayud / Monasterio de Piedra)

Río Piedra. Aragón
Good · Brown Trout
Grasshopper Pattern · 10-14
Goodlive now
A proper day on the water
River steady at a fishable height. A proper day for it. Work the seams with an upstream nymph, switch to the dry when they show.
75% confidence
What moved it
  • LevelProxyvia Río Abión
  • Water temp8.3°C
  • ClarityClear
Today's fly
Grasshopper Pattern
Grasshopper Pattern10-14
Proven pattern for this period
Conditions on the water
Proxy gauge
Level
Steady
Proxy
via Río Abión
Water temp8.3°C
ClarityClear
Weather21°C
WindN 8 km/h
Pressure1026 hPa
Rain · recent0.0 mm
Rain · ahead0.0 mm

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

Water temperature for Brown Trout
Cool — slow
8°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
Good — water clarity is working for you, but river flow is the limiting factor today.
Likely species
Mayflies
Stoneflies
Gammarids
Hatch timeline · todayQuiet day

Hatch predictions

Today's headline hatch shown — see all 4 active hatches hour by hour as a supporter.

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Sub-surface · on the nymphunder the surface

Hatch predictions

Supporters see the full sub-surface read.

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Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Top prey shown — see all 2 as a supporter.

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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 · October highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
2
1
Brown SedgeHatch
2
3
3
3
2
Small SpurwingHatch
2
3
3
3
2
Freshwater ShrimpHatch
2
3
3
3
3
3
3
3
3
3
3
2
Small Dark OliveHatch
2
3
3
3
2

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

Ranked for today
Fly box · Brown Trout
Permits & access
Permit required — see local rules.
  • Se requiere licencia de pesca de Aragón; los cotos y los tramos libres tienen cada uno sus propias fechas, cupos y normas de método
  • La trucha solo es un objetivo legítimo en los tramos clasificados como salmonícolas; confirma el estado del tramo antes de pescar.
What's coming
Plan ahead
5-day outlook
Gallery · 2
  1. Río Piedra. Aragón
  2. Terrain map of the venue
    Terrain map
The full read · show the working · for Brown Trout · confidence 75%
How the 67 is built — score × weight = contribution
Temperature70 × 28%19.6
Flow40 × 22%8.8
Clarity95 × 18%17.1
Feeding Time65 × 13%8.5
Pressure80 × 7%5.6
Insect activity59 × 12%7.1
Conditions total= 67
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via Río Abiónproxy
Prey activitysurvey-backed invertebrate datasurvey
What would change the calculation
The dawn and dusk windows score higher than the midday lull.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Trout tercer Saturday de March → 15 October

    Aragón general C&R free-water dates (third Saturday of March, 2026-03-21, to 15 October) per the 2026 Orden de vedas. Iberian System tributaries of the Jalón — confirm the exact coto/free-water status per beat, since flows are highly seasonal and trout are only a legitimate target in salmonid-classified reaches. Dates added 2026-09-09; previously an unparseable placeholder.

Related guides
Chalkstream Playbooklimestone spring creek — same tacticsPyrenees PlaybookSpanish riversEuro Nymphingsubsurface methods
Booking & contacts