Freestone · Schist · Cévennes / Lozère-Ardèche, FR

Chassezac

Chassezac — No need for HDR
Poor · Brown Trout
Pheasant Tail Nymph · 14-18
New ruleReported 21 Aug 2026

Severe drought restrictions (crise) in force

A préfectoral drought order places this catchment's surface water at crise, the highest of France's four restriction tiers. Fishing itself is not named in the order, but flows are low and water-use restrictions are in force. Zone: Cèze amont (de source à la confluence Tave jusqu'à la confluence avec la Claysse, ruisseau de la Clays) (dépt 30).

Arrêté préfectoral n°37847 ↗

Temporary notices from official orders and recent fishery reports — they clear automatically once out of date. Always confirm locally before travelling.

Poorlive now
Not the day for it
River temperature is the limiting factor today, not the flow. This is not the day to push it. Check the thermal advice above before you head out.
90% confidence
What moved it
  • LevelProxyvia Loire (Upper)
  • Water temp22.1°C
  • ClarityClear
Today's fly
Pheasant Tail Nymph
Pheasant Tail Nymph14-18
Upstream
Conditions on the water
Proxy gauge
Level
Steady
Proxy
via Loire (Upper)
Water temp22.1°C
ClarityClear
Weather24°C
WindW 16 km/h
Pressure1017 hPa
Rain · recent0.0 mm
Rain · ahead0.7 mm

No gauge on this water — conditions are inferred from Loire (Upper). The trend transfers, the absolute level does not.

Water temperature for Brown Trout
Warm — slow
22°C est.ideal 10–16°C
0°14°28°
How to fish it · for Brown Trout
When
Through the open trout season. Spring olives April through May; sedges through summer evenings.
Where
Pool tails and pocket water through the Lozère-Ardèche valley. Cévennes freestone — clear water, fast pockets.
Method
Upstream dry to risers; dry-dropper through the riffles. The water reads clear — long leader, fine tippet. Move slowly, cast accurately.
Kit
9 ft #4 — French freestone default. Floating line, 12 ft leader to 4 to 5 lb fluoro. Studded boots.
Why this works
Water at 22.1°C. This is the line where catch-and-release kills brown trout. Do not fish for them today.
Hatch timeline · todayPeak at 6am

Hatch predictions

Today's headline hatch shown — see all 2 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(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 · August highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Trout seasonSeason
1
2
2
2
2
2
1
Evening SedgeHatch
2
3
3
3
2
Large Dark OliveHatch
1
2
2
1
Iron BlueHatch
1
2
2
2
2
2
2
1
Blue Winged OliveHatch
1
2
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.
  • AAPPMA Lozère / Ardèche
  • 1ère catégorie
  • Wild trout reserve zones in the upper reaches.
What's coming
Plan ahead
5-day outlook
Cooler water nearby · 1
Probably above the Brown Trout safety line — these are likely cooler, but carry a thermometer.
Beaume
8.0 km
~17°C
Brown trout
Gallery · 2
  1. Chassezac — No need for HDR
    No need for HDR
  2. Terrain map of the venue
    Terrain map
Water quality (WFD)
  • Ecology: Good
  • Chemical: Unknown
What this classification means

WFD ecological status Moderate → Good corrected to EEA WISE 2022 (3rd RBMP) classification for waterbody FRDR413C (was a stale earlier-cycle value). Source: EEA WISE SWB_SurfaceWaterBody (discodata.eea.europa.eu), verified 2026-06-18.

WFD classification · FRDR413C

The full read · show the working · for Brown Trout · confidence 90%
How the 2 is built — score × weight = contribution
Temperature1 × 28%0.3
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time65 × 13%8.5
Pressure80 × 7%5.6
Insect activity67 × 12%8.0
Limiting factor: Water temperature (22.1°C) is outside Brown Trout's preferred range (10–16°C)= 57
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via Loire (Upper)proxy
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
Apple MapsGoogle Maps
Seasons & zones
  • Trout 2nd Saturday of March → 3rd Sunday of September
Related guides
Pyrenees PlaybookFrench riversEuro Nymphingsubsurface methods
Booking & contacts