Freestone · Schist · Cévennes / Lozère-Ardèche, FR

Chassezac

Chassezac — No need for HDR

The Chassezac is a small river that does a very dramatic thing: it starts on the schist of Mont Lozère, runs south through trout water that could sit anywhere in the Cévennes, and then cuts abruptly into the limestone to form the Gorges du Chassezac — a vertical-walled canyon that local kayakers speak about in tones of respectful fear.

Poor · Brown Trout
Pheasant Tail Nymph · 14-18
New ruleReported 21 Aug 2026

Severe drought restrictions (crise) in force

VigiEau lists this venue's surface-water zone (Cèze amont (de source à la confluence Tave jusqu'à la confluence avec la Claysse, ruisseau de la Clays), dépt 30) at crise, under an official préfectoral drought arrêté. Fishing is not itself banned by it, but water levels are low — go gently on stressed fish.

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Temporary notices from official orders and recent fishery reports — they clear automatically once out of date.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.

Closed season
Out of season. Try elsewhere.
Closed — confidence not applicable today.
What moved it
  • LevelProxyvia Loire (Upper)
  • Water temp16.5°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 temp16.5°C
ClarityClear
Weather20°C
WindS 23 km/h
Pressure1021 hPa
Rain · recent0.0 mm
Rain · ahead70.1 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
17°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.
Likely species
Hatch timeline · todayPeak at 11am

Hatch predictions

Today's headline hatch shown — see all 12 active hatches hour by hour as a supporter.

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Sub-surface · on the nymphunder the surface

Hatch predictions

Top nymph shown — see all 2 guilds as a supporter.

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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 · September 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

More balanced than the mountain-river pack. French nymphing still matters, but there is more room for dries, spiders and general searching flies.

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
Other water nearby · 5
Gallery · 2
  1. Chassezac — No need for HDR
    No need for HDR
  2. Terrain map of the venue
    Terrain map
About this water

The Chassezac is a small river that does a very dramatic thing: it starts on the schist of Mont Lozère, runs south through trout water that could sit anywhere in the Cévennes, and then cuts abruptly into the limestone to form the Gorges du Chassezac — a vertical-walled canyon that local kayakers speak about in tones of respectful fear. The trout fishing is in the upper reaches above the gorges and in the tributary streams that feed it. It is the kind of water where you park the car at a back-road bridge, walk upstream for half an hour, and then realise you probably won't see another angler all day. The usable beats are above Les Vans and upstream of the first hydroelectric barrage. The fish are small — six to ten inches is the honest range, with occasional better fish in the deeper pools — but they rise confidently to a well-presented dry in the right weather. March through early June is the window. After that, like most Cévennes water, the Chassezac thins out to a trickle and the fish retreat to the holding pools. The schist colour is always there, even at low water: dark water that looks almost peat-stained but isn't.

Hatches & food

In Cévennes and other Mediterranean-season trout rivers, spring olives and stoneflies dominate while flows are cool and comfortable for fish, followed by a relatively short but intense caddis spell as the rivers warm; terrestrials and small buzzers can offer chances around morning and evening once dangerous heat and skinny water ease off, with a further autumn reset of olives, small caddis and buzzers after the first good cooling rains.

  • Schist
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 0 is built — score × weight = contribution
Temperature82 × 28%23.0
Flow80 × 22%17.6
Clarity95 × 18%17.1
Feeding Time70 × 13%9.1
Pressure80 × 7%5.6
Insect activity75 × 12%9.0
Conditions total= 81
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowproxy via Loire (Upper)proxy
Prey activitysurvey-backed invertebrate datasurvey
Directions
Seasons & zones
  • Trout 2nd Saturday of March → 3rd Sunday of September
Related guides
Booking & contacts